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+18lwl_branch
+
+1
\ No newline at end of file
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diff --git a/src/data/Contact.java b/src/data/Contact.java
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+++ b/src/data/Contact.java
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+`/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.data;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.provider.ContactsContract.CommonDataKinds.Phone;
+import android.provider.ContactsContract.Data;
+import android.telephony.PhoneNumberUtils;
+import android.util.Log;
+
+import java.util.HashMap;
+//change
+public class Contact {//联系人
+    private static HashMap<String, String> sContactCache;
+    private static final String TAG = "Contact";    
+
+    //定义字符串CALLER_ID_SELECTION
+    private static final String CALLER_ID_SELECTION = "PHONE_NUMBERS_EQUAL(" + Phone.NUMBER
+    + ",?) AND " + Data.MIMETYPE + "='" + Phone.CONTENT_ITEM_TYPE + "'"
+    + " AND " + Data.RAW_CONTACT_ID + " IN "
+            + "(SELECT raw_contact_id "
+            + " FROM phone_lookup"
+            + " WHERE min_match = '+')";
+            
+    //获取联系人
+    public static String getContact(Context context, String phoneNumber) {
+        if(sContactCache == null) {
+            sContactCache = new HashMap<String, String>();
+        }
+        
+        //查找HashMap中是否有phoneNumeber信息
+        if(sContactCache.containsKey(phoneNumber)) {
+            return sContactCache.get(phoneNumber);
+        }
+
+        String selection = CALLER_ID_SELECTION.replace("+",
+                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
+        //查找数据库中phoneNumber信息
+        Cursor cursor = context.getContentResolver().query(
+                Data.CONTENT_URI,
+                new String [] { Phone.DISPLAY_NAME },
+                selection,
+                new String[] { phoneNumber },
+                null);
+
+            //判定查询结果
+            //moveToFirst()返回第一条
+
+        if (cursor != null && cursor.moveToFirst()) {
+            try {
+                //找到关键信息
+                String name =cursor.getString(0);
+                sContactCache.put(phoneNumber, name);
+                return name;
+            //异常
+            } catch (IndexOutOfBoundsException e) {
+                Log.e(TAG, " Cursor get string error " + e.toString());
+                return null;
+            } finally {
+                cursor.close();
+            }
+            //未找到相关信息
+        } else {
+            Log.d(TAG, "No contact matched with number:" + phoneNumber);
+            return null;
+        }
+    }
+}
diff --git a/src/data/Notes.java b/src/data/Notes.java
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--- /dev/null
+++ b/src/data/Notes.java
@@ -0,0 +1,286 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.data;
+
+import android.net.Uri;
+//Note 类中定义了很多常量，这些常量大多是int型和string型
+public class Notes {
+    public static final String AUTHORITY = "micode_notes";
+    public static final String TAG = "Notes";
+    //这三个常量对NoteColumns.TYPE的值进行设置时会用到
+    public static final int TYPE_NOTE     = 0;
+    public static final int TYPE_FOLDER   = 1;
+    public static final int TYPE_SYSTEM   = 2;
+
+    /**
+     * Following IDs are system folders' identifiers
+     * {@link Notes#ID_ROOT_FOLDER } is default folder
+     * {@link Notes#ID_TEMPARAY_FOLDER } is for notes belonging no folder
+     * {@link Notes#ID_CALL_RECORD_FOLDER} is to store call records
+     */
+    public static final int ID_ROOT_FOLDER = 0;
+    public static final int ID_TEMPARAY_FOLDER = -1;
+    public static final int ID_CALL_RECORD_FOLDER = -2;
+    public static final int ID_TRASH_FOLER = -3;
+
+    public static final String INTENT_EXTRA_ALERT_DATE = "net.micode.notes.alert_date";
+    public static final String INTENT_EXTRA_BACKGROUND_ID = "net.micode.notes.background_color_id";
+    public static final String INTENT_EXTRA_WIDGET_ID = "net.micode.notes.widget_id";
+    public static final String INTENT_EXTRA_WIDGET_TYPE = "net.micode.notes.widget_type";
+    public static final String INTENT_EXTRA_FOLDER_ID = "net.micode.notes.folder_id";
+    public static final String INTENT_EXTRA_CALL_DATE = "net.micode.notes.call_date";
+
+    public static final int TYPE_WIDGET_INVALIDE      = -1;
+    public static final int TYPE_WIDGET_2X            = 0;
+    public static final int TYPE_WIDGET_4X            = 1;
+
+    public static class DataConstants {
+        public static final String NOTE = TextNote.CONTENT_ITEM_TYPE;
+        public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE;
+    }
+
+    /**
+     * Uri to query all notes and folders
+     */
+    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
+    //定义查询便签和文件夹的指针
+
+    /**
+     * Uri to query data
+     */
+    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
+    ///定义查找数据的指针
+
+    //定义NoteColumns的常量，用于后面创建数据库的表头
+    public interface NoteColumns {
+        /**
+         * The unique ID for a row
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String ID = "_id";
+
+        /**
+         * The parent's id for note or folder
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String PARENT_ID = "parent_id";
+
+        /**
+         * Created data for note or folder
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String CREATED_DATE = "created_date";
+
+        /**
+         * Latest modified date
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String MODIFIED_DATE = "modified_date";
+
+
+        /**
+         * Alert date
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String ALERTED_DATE = "alert_date";
+
+        /**
+         * Folder's name or text content of note
+         * <P> Type: TEXT </P>
+         */
+        public static final String SNIPPET = "snippet";
+
+        /**
+         * Note's widget id
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String WIDGET_ID = "widget_id";
+
+        /**
+         * Note's widget type
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String WIDGET_TYPE = "widget_type";
+
+        /**
+         * Note's background color's id
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String BG_COLOR_ID = "bg_color_id";
+
+        /**
+         * For text note, it doesn't has attachment, for multi-media
+         * note, it has at least one attachment
+         * <P> Type: INTEGER </P>
+         */
+        public static final String HAS_ATTACHMENT = "has_attachment";
+
+        /**
+         * Folder's count of notes
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String NOTES_COUNT = "notes_count";
+
+        /**
+         * The file type: folder or note
+         * <P> Type: INTEGER </P>
+         */
+        public static final String TYPE = "type";
+
+        /**
+         * The last sync id
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String SYNC_ID = "sync_id";
+
+        /**
+         * Sign to indicate local modified or not
+         * <P> Type: INTEGER </P>
+         */
+        public static final String LOCAL_MODIFIED = "local_modified";
+
+        /**
+         * Original parent id before moving into temporary folder
+         * <P> Type : INTEGER </P>
+         */
+        public static final String ORIGIN_PARENT_ID = "origin_parent_id";
+
+        /**
+         * The gtask id
+         * <P> Type : TEXT </P>
+         */
+        public static final String GTASK_ID = "gtask_id";
+
+        /**
+         * The version code
+         * <P> Type : INTEGER (long) </P>
+         */
+        public static final String VERSION = "version";
+    }//这些常量主要是定义便签的属性的
+
+    //定义DataColumns的常量，用于后面创建数据库的表头
+    public interface DataColumns {
+        /**
+         * The unique ID for a row
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String ID = "_id";
+
+        /**
+         * The MIME type of the item represented by this row.
+         * <P> Type: Text </P>
+         */
+        public static final String MIME_TYPE = "mime_type";
+
+        /**
+         * The reference id to note that this data belongs to
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String NOTE_ID = "note_id";
+
+        /**
+         * Created data for note or folder
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String CREATED_DATE = "created_date";
+
+        /**
+         * Latest modified date
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String MODIFIED_DATE = "modified_date";
+
+        /**
+         * Data's content
+         * <P> Type: TEXT </P>
+         */
+        public static final String CONTENT = "content";
+
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * integer data type
+         * <P> Type: INTEGER </P>
+         */
+        public static final String DATA1 = "data1";
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * integer data type
+         * <P> Type: INTEGER </P>
+         */
+        public static final String DATA2 = "data2";
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * TEXT data type
+         * <P> Type: TEXT </P>
+         */
+        public static final String DATA3 = "data3";
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * TEXT data type
+         * <P> Type: TEXT </P>
+         */
+        public static final String DATA4 = "data4";
+
+        /**
+         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
+         * TEXT data type
+         * <P> Type: TEXT </P>
+         */
+        public static final String DATA5 = "data5";
+    }//主要是定义存储便签内容数据的
+
+    public static final class TextNote implements DataColumns {
+        /**
+         * Mode to indicate the text in check list mode or not
+         * <P> Type: Integer 1:check list mode 0: normal mode </P>
+         */
+        public static final String MODE = DATA1;
+
+        public static final int MODE_CHECK_LIST = 1;
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/text_note";
+
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note";
+
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");
+    }
+    //文本内容的数据结构
+
+    public static final class CallNote implements DataColumns {
+        /**
+         * Call date for this record
+         * <P> Type: INTEGER (long) </P>
+         */
+        public static final String CALL_DATE = DATA1;
+
+        /**
+         * Phone number for this record
+         * <P> Type: TEXT </P>
+         */
+        public static final String PHONE_NUMBER = DATA3;
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/call_note";
+
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note";
+
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note");
+    }//电话内容的数据结构
+}
diff --git a/src/data/NotesDatabaseHelper.java b/src/data/NotesDatabaseHelper.java
new file mode 100644
index 0000000..ed22d53
--- /dev/null
+++ b/src/data/NotesDatabaseHelper.java
@@ -0,0 +1,365 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+ package net.micode.notes.data;
+ 
+ import android.content.ContentValues;//就是用于保存一些数据（string boolean byte double float int long short ...）信息，这些信息可以被数据库操作时使用。
+ import android.content.Context;//加载和访问资源。（android中主要是这两个功能，但是这里具体不清楚）
+ import android.database.sqlite.SQLiteDatabase;//主要提供了对应于添加、删除、更新、查询的操作方法： insert()、delete()、update()和query()。配合content.values
+ import android.database.sqlite.SQLiteOpenHelper;//用来管理数据的创建和版本更新
+ import android.util.Log;
+  
+ import net.micode.notes.data.Notes.DataColumns;
+ import net.micode.notes.data.Notes.DataConstants;
+ import net.micode.notes.data.Notes.NoteColumns;
+ //数据库操作，用SQLOpenhelper,对一些note和文件进行数据库的操作，比如删除文件后，将文件里的note也相应删除
+  
+ public class NotesDatabaseHelper extends SQLiteOpenHelper {
+     private static final String DB_NAME = "note.db";
+  
+     private static final int DB_VERSION = 4;
+  
+     public interface TABLE {    //接口，分成note和data，在后面的程序里分别使用过
+         public static final String NOTE = "note";
+  
+         public static final String DATA = "data";
+     }
+  
+     private static final String TAG = "NotesDatabaseHelper";
+  
+     private static NotesDatabaseHelper mInstance;
+  
+     private static final String CREATE_NOTE_TABLE_SQL =
+         "CREATE TABLE " + TABLE.NOTE + "(" +
+             NoteColumns.ID + " INTEGER PRIMARY KEY," +
+             NoteColumns.PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
+             NoteColumns.ALERTED_DATE + " INTEGER NOT NULL DEFAULT 0," +
+             NoteColumns.BG_COLOR_ID + " INTEGER NOT NULL DEFAULT 0," +
+             NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+             NoteColumns.HAS_ATTACHMENT + " INTEGER NOT NULL DEFAULT 0," +
+             NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+             NoteColumns.NOTES_COUNT + " INTEGER NOT NULL DEFAULT 0," +
+             NoteColumns.SNIPPET + " TEXT NOT NULL DEFAULT ''," +
+             NoteColumns.TYPE + " INTEGER NOT NULL DEFAULT 0," +
+             NoteColumns.WIDGET_ID + " INTEGER NOT NULL DEFAULT 0," +
+             NoteColumns.WIDGET_TYPE + " INTEGER NOT NULL DEFAULT -1," +
+             NoteColumns.SYNC_ID + " INTEGER NOT NULL DEFAULT 0," +
+             NoteColumns.LOCAL_MODIFIED + " INTEGER NOT NULL DEFAULT 0," +
+             NoteColumns.ORIGIN_PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
+             NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," +
+             NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
+         ")";//数据库中需要存储的项目的名称，就相当于创建一个表格的表头的内容。
+  
+     private static final String CREATE_DATA_TABLE_SQL =
+         "CREATE TABLE " + TABLE.DATA + "(" +
+             DataColumns.ID + " INTEGER PRIMARY KEY," +
+             DataColumns.MIME_TYPE + " TEXT NOT NULL," +
+             DataColumns.NOTE_ID + " INTEGER NOT NULL DEFAULT 0," +
+             NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+             NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
+             DataColumns.CONTENT + " TEXT NOT NULL DEFAULT ''," +
+             DataColumns.DATA1 + " INTEGER," +
+             DataColumns.DATA2 + " INTEGER," +
+             DataColumns.DATA3 + " TEXT NOT NULL DEFAULT ''," +
+             DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," +
+             DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +
+         ")";//和上面的功能一样，主要是存储的项目不同
+  
+     private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
+         "CREATE INDEX IF NOT EXISTS note_id_index ON " +
+         TABLE.DATA + "(" + DataColumns.NOTE_ID + ");";//存储便签编号的一个数据表格
+  
+     /**
+      * Increase folder's note count when move note to the folder
+      */
+     private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
+         "CREATE TRIGGER increase_folder_count_on_update "+
+         " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
+         " BEGIN " +
+         "  UPDATE " + TABLE.NOTE +
+         "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
+         "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
+         " END";//在文件夹中移入一个Note之后需要更改的数据的表格。
+  
+     /**
+      * Decrease folder's note count when move note from folder
+      */
+     private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
+         "CREATE TRIGGER decrease_folder_count_on_update " +
+         " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
+         " BEGIN " +
+         "  UPDATE " + TABLE.NOTE +
+         "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
+         "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
+         "  AND " + NoteColumns.NOTES_COUNT + ">0" + ";" +
+         " END";//在文件夹中移出一个Note之后需要更改的数据的表格。
+  
+     /**
+      * Increase folder's note count when insert new note to the folder
+      */
+     private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
+         "CREATE TRIGGER increase_folder_count_on_insert " +
+         " AFTER INSERT ON " + TABLE.NOTE +
+         " BEGIN " +
+         "  UPDATE " + TABLE.NOTE +
+         "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
+         "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
+         " END";//在文件夹中插入一个Note之后需要更改的数据的表格。
+  
+     /**
+      * Decrease folder's note count when delete note from the folder
+      */
+     private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =
+         "CREATE TRIGGER decrease_folder_count_on_delete " +
+         " AFTER DELETE ON " + TABLE.NOTE +
+         " BEGIN " +
+         "  UPDATE " + TABLE.NOTE +
+         "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
+         "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
+         "  AND " + NoteColumns.NOTES_COUNT + ">0;" +
+         " END";//在文件夹中删除一个Note之后需要更改的数据的表格。
+  
+     /**
+      * Update note's content when insert data with type {@link DataConstants#NOTE}
+      */
+     private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =
+         "CREATE TRIGGER update_note_content_on_insert " +
+         " AFTER INSERT ON " + TABLE.DATA +
+         " WHEN new." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+         " BEGIN" +
+         "  UPDATE " + TABLE.NOTE +
+         "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
+         "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
+         " END";//在文件夹中对一个Note导入新的数据之后需要更改的数据的表格。
+  
+     /**
+      * Update note's content when data with {@link DataConstants#NOTE} type has changed
+      */
+     private static final String DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER =
+         "CREATE TRIGGER update_note_content_on_update " +
+         " AFTER UPDATE ON " + TABLE.DATA +
+         " WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+         " BEGIN" +
+         "  UPDATE " + TABLE.NOTE +
+         "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
+         "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
+         " END";//Note数据被修改后需要更改的数据的表格。
+  
+     /**
+      * Update note's content when data with {@link DataConstants#NOTE} type has deleted
+      */
+     private static final String DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER =
+         "CREATE TRIGGER update_note_content_on_delete " +
+         " AFTER delete ON " + TABLE.DATA +
+         " WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
+         " BEGIN" +
+         "  UPDATE " + TABLE.NOTE +
+         "   SET " + NoteColumns.SNIPPET + "=''" +
+         "  WHERE " + NoteColumns.ID + "=old." + DataColumns.NOTE_ID + ";" +
+         " END";//Note数据被删除后需要更改的数据的表格。
+  
+     /**
+      * Delete datas belong to note which has been deleted
+      */
+     private static final String NOTE_DELETE_DATA_ON_DELETE_TRIGGER =
+         "CREATE TRIGGER delete_data_on_delete " +
+         " AFTER DELETE ON " + TABLE.NOTE +
+         " BEGIN" +
+         "  DELETE FROM " + TABLE.DATA +
+         "   WHERE " + DataColumns.NOTE_ID + "=old." + NoteColumns.ID + ";" +
+         " END";//删除已删除的便签的数据后需要更改的数据的表格。
+  
+     /**
+      * Delete notes belong to folder which has been deleted
+      */
+     private static final String FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER =
+         "CREATE TRIGGER folder_delete_notes_on_delete " +
+         " AFTER DELETE ON " + TABLE.NOTE +
+         " BEGIN" +
+         "  DELETE FROM " + TABLE.NOTE +
+         "   WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
+         " END";//删除已删除的文件夹的便签后需要更改的数据的表格。
+  
+     /**
+      * Move notes belong to folder which has been moved to trash folder
+      */
+     private static final String FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER =
+         "CREATE TRIGGER folder_move_notes_on_trash " +
+         " AFTER UPDATE ON " + TABLE.NOTE +
+         " WHEN new." + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
+         " BEGIN" +
+         "  UPDATE " + TABLE.NOTE +
+         "   SET " + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
+         "  WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
+         " END";//还原垃圾桶中便签后需要更改的数据的表格。
+  
+     public NotesDatabaseHelper(Context context) {
+         super(context, DB_NAME, null, DB_VERSION);
+     }//构造函数，传入数据库的名称和版本
+  
+     public void createNoteTable(SQLiteDatabase db) {
+         db.execSQL(CREATE_NOTE_TABLE_SQL);
+         reCreateNoteTableTriggers(db);
+         createSystemFolder(db);
+         Log.d(TAG, "note table has been created");
+     }//创建表格（用来存储标签属性）
+  
+     private void reCreateNoteTableTriggers(SQLiteDatabase db) {
+         db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_update");
+         db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_update");
+         db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_delete");
+         db.execSQL("DROP TRIGGER IF EXISTS delete_data_on_delete");
+         db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_insert");
+         db.execSQL("DROP TRIGGER IF EXISTS folder_delete_notes_on_delete");
+         db.execSQL("DROP TRIGGER IF EXISTS folder_move_notes_on_trash");
+  
+         db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER);
+         db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER);
+         db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER);
+         db.execSQL(NOTE_DELETE_DATA_ON_DELETE_TRIGGER);
+         db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER);
+         db.execSQL(FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER);
+         db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER);
+     }//execSQL是数据库操作的API，主要是更改行为的SQL语句。
+     //在这里主要是用来重新创建上述定义的表格用的，先删除原来有的数据库的触发器再重新创建新的数据库
+  
+     private void createSystemFolder(SQLiteDatabase db) {
+         ContentValues values = new ContentValues();
+  
+         /**
+          * call record foler for call notes
+          */
+         values.put(NoteColumns.ID, Notes.ID_CALL_RECORD_FOLDER);
+         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+         db.insert(TABLE.NOTE, null, values);
+  
+         /**
+          * root folder which is default folder
+          */
+         values.clear();
+         values.put(NoteColumns.ID, Notes.ID_ROOT_FOLDER);
+         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+         db.insert(TABLE.NOTE, null, values);
+  
+         /**
+          * temporary folder which is used for moving note
+          */
+         values.clear();
+         values.put(NoteColumns.ID, Notes.ID_TEMPARAY_FOLDER);
+         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+         db.insert(TABLE.NOTE, null, values);
+  
+         /**
+          * create trash folder
+          */
+         values.clear();
+         values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
+         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+         db.insert(TABLE.NOTE, null, values);
+     }//创建几个系统文件夹
+  
+     public void createDataTable(SQLiteDatabase db) {
+         db.execSQL(CREATE_DATA_TABLE_SQL);
+         reCreateDataTableTriggers(db);
+         db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL);
+         Log.d(TAG, "data table has been created");
+     }//创建表格（用来存储标签内容）
+  
+     private void reCreateDataTableTriggers(SQLiteDatabase db) {
+         db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_insert");
+         db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_update");
+         db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_delete");
+  
+         db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER);
+         db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER);
+         db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER);
+     }//同上面的execSQL
+  
+     static synchronized NotesDatabaseHelper getInstance(Context context) {
+         if (mInstance == null) {
+             mInstance = new NotesDatabaseHelper(context);
+         }
+         return mInstance;
+     }//上网查是为解决同一时刻只能有一个线程执行.
+      //在写程序库代码时，有时有一个类需要被所有的其它类使用，
+      //但又要求这个类只能被实例化一次，是个服务类，定义一次，其它类使用同一个这个类的实例
+  
+     @Override
+     public void onCreate(SQLiteDatabase db) {
+         createNoteTable(db);
+         createDataTable(db);
+     }//实现两个表格（上面创建的两个表格）
+  
+     @Override
+     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+         boolean reCreateTriggers = false;
+         boolean skipV2 = false;
+  
+         if (oldVersion == 1) {
+             upgradeToV2(db);
+             skipV2 = true; // this upgrade including the upgrade from v2 to v3
+             oldVersion++;
+         }
+  
+         if (oldVersion == 2 && !skipV2) {
+             upgradeToV3(db);
+             reCreateTriggers = true;
+             oldVersion++;
+         }
+  
+         if (oldVersion == 3) {
+             upgradeToV4(db);
+             oldVersion++;
+         }
+  
+         if (reCreateTriggers) {
+             reCreateNoteTableTriggers(db);
+             reCreateDataTableTriggers(db);
+         }
+  
+         if (oldVersion != newVersion) {
+             throw new IllegalStateException("Upgrade notes database to version " + newVersion
+                     + "fails");
+         }
+     }//数据库版本的更新（数据库内容的更改）
+  
+     private void upgradeToV2(SQLiteDatabase db) {
+         db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE);
+         db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA);
+         createNoteTable(db);
+         createDataTable(db);
+     }//更新到V2版本
+  
+     private void upgradeToV3(SQLiteDatabase db) {
+         // drop unused triggers
+         db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_insert");
+         db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_delete");
+         db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_update");
+         // add a column for gtask id
+         db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID
+                 + " TEXT NOT NULL DEFAULT ''");
+         // add a trash system folder
+         ContentValues values = new ContentValues();
+         values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
+         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+         db.insert(TABLE.NOTE, null, values);
+     }//更新到V3版本
+  
+     private void upgradeToV4(SQLiteDatabase db) {
+         db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
+                 + " INTEGER NOT NULL DEFAULT 0");
+     }//更新到V4版本,但是不知道V2、V3、V4是什么意思
+ }
\ No newline at end of file
diff --git a/src/data/NotesProvider.java b/src/data/NotesProvider.java
new file mode 100644
index 0000000..278d363
--- /dev/null
+++ b/src/data/NotesProvider.java
@@ -0,0 +1,336 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+ package net.micode.notes.data;
+ 
+ import android.app.SearchManager;
+ import android.content.ContentProvider;
+ import android.content.ContentUris;
+ import android.content.ContentValues;
+ import android.content.Intent;
+ import android.content.UriMatcher;
+ import android.database.Cursor;
+ import android.database.sqlite.SQLiteDatabase;
+ import android.net.Uri;
+ import android.text.TextUtils;
+ import android.util.Log;
+  
+ import net.micode.notes.R;
+ import net.micode.notes.data.Notes.DataColumns;
+ import net.micode.notes.data.Notes.NoteColumns;
+ import net.micode.notes.data.NotesDatabaseHelper.TABLE;
+ //为存储和获取数据提供接口。可以在不同的应用程序之间共享数据
+ //ContentProvider提供的方法
+ //query：查询
+ //insert：插入
+ //update：更新
+ //delete：删除
+ //getType：得到数据类型
+ public class NotesProvider extends ContentProvider {
+     // UriMatcher用于匹配Uri
+     private static final UriMatcher mMatcher;
+  
+     private NotesDatabaseHelper mHelper;
+  
+     private static final String TAG = "NotesProvider";
+  
+     private static final int URI_NOTE            = 1;
+     private static final int URI_NOTE_ITEM       = 2;
+     private static final int URI_DATA            = 3;
+     private static final int URI_DATA_ITEM       = 4;
+  
+     private static final int URI_SEARCH          = 5;
+     private static final int URI_SEARCH_SUGGEST  = 6;
+  
+     static {
+         // 创建UriMatcher时，调用UriMatcher(UriMatcher.NO_MATCH)表示不匹配任何路径的返回码
+         mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
+         // 把需要匹配Uri路径全部给注册上
+         mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
+         mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);
+         mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);
+         mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM);
+         mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH);
+         mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST);
+         mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST);
+     }
+  
+     /**
+      * x'0A' represents the '\n' character in sqlite. For title and content in the search result,
+      * we will trim '\n' and white space in order to show more information.
+      */
+     // 声明 NOTES_SEARCH_PROJECTION
+     private static final String NOTES_SEARCH_PROJECTION = NoteColumns.ID + ","
+         + NoteColumns.ID + " AS " + SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA + ","
+         + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_1 + ","
+         + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_2 + ","
+         + R.drawable.search_result + " AS " + SearchManager.SUGGEST_COLUMN_ICON_1 + ","
+         + "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + ","
+         + "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA;
+     // 声明NOTES_SNIPPET_SEARCH_QUERY
+     private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION
+         + " FROM " + TABLE.NOTE
+         + " WHERE " + NoteColumns.SNIPPET + " LIKE ?"
+         + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER
+         + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;
+  
+     @Override
+     // Context只有在onCreate()中才被初始化
+     // 对mHelper进行实例化
+     public boolean onCreate() {
+         mHelper = NotesDatabaseHelper.getInstance(getContext());
+         return true;
+     }
+  
+     @Override
+     // 查询uri在数据库中对应的位置
+     public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
+             String sortOrder) {
+         Cursor c = null;
+         // 获取可读数据库
+         SQLiteDatabase db = mHelper.getReadableDatabase();
+         String id = null;
+         // 匹配查找uri
+         switch (mMatcher.match(uri)) {
+             // 对于不同的匹配值，在数据库中查找相应的条目
+             case URI_NOTE:
+                 c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
+                         sortOrder);
+                 break;
+             case URI_NOTE_ITEM:
+                 id = uri.getPathSegments().get(1);
+                 c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id
+                         + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                 break;
+             case URI_DATA:
+                 c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null,
+                         sortOrder);
+                 break;
+             case URI_DATA_ITEM:
+                 id = uri.getPathSegments().get(1);
+                 c = db.query(TABLE.DATA, projection, DataColumns.ID + "=" + id
+                         + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                 break;
+             case URI_SEARCH:
+             case URI_SEARCH_SUGGEST:
+                 if (sortOrder != null || projection != null) {
+                     // 不合法的参数异常
+                     throw new IllegalArgumentException(
+                             "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
+                 }
+  
+                 String searchString = null;
+                 if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) {
+                     if (uri.getPathSegments().size() > 1) {
+                         // getPathSegments()方法得到一个String的List，
+                         // 在uri.getPathSegments().get(1)为第2个元素
+                         searchString = uri.getPathSegments().get(1);
+                     }
+                 } else {
+                     searchString = uri.getQueryParameter("pattern");
+                 }
+  
+                 if (TextUtils.isEmpty(searchString)) {
+                     return null;
+                 }
+  
+                 try {
+                     searchString = String.format("%%%s%%", searchString);
+                     c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY,
+                             new String[] { searchString });
+                 } catch (IllegalStateException ex) {
+                     Log.e(TAG, "got exception: " + ex.toString());
+                 }
+                 break;
+             default:
+                 // 抛出异常
+                 throw new IllegalArgumentException("Unknown URI " + uri);
+         }
+         if (c != null) {
+             c.setNotificationUri(getContext().getContentResolver(), uri);
+         }
+         return c;
+     }
+  
+     @Override
+     // 插入一个uri
+     public Uri insert(Uri uri, ContentValues values) {
+         // 获得可写的数据库
+         SQLiteDatabase db = mHelper.getWritableDatabase();
+         long dataId = 0, noteId = 0, insertedId = 0;
+         switch (mMatcher.match(uri)) {
+             // 新增一个条目
+             case URI_NOTE:
+                 insertedId = noteId = db.insert(TABLE.NOTE, null, values);
+                 break;
+             // 如果存在，查找NOTE_ID
+             case URI_DATA:
+                 if (values.containsKey(DataColumns.NOTE_ID)) {
+                     noteId = values.getAsLong(DataColumns.NOTE_ID);
+                 } else {
+                     Log.d(TAG, "Wrong data format without note id:" + values.toString());
+                 }
+                 insertedId = dataId = db.insert(TABLE.DATA, null, values);
+                 break;
+            default:
+                 throw new IllegalArgumentException("Unknown URI " + uri);
+         }
+         // Notify the note uri
+         // notifyChange获得一个ContextResolver对象并且更新里面的内容
+         if (noteId > 0) {
+             getContext().getContentResolver().notifyChange(
+                     ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
+         }
+  
+         // Notify the data uri
+         if (dataId > 0) {
+             getContext().getContentResolver().notifyChange(
+                     ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
+         }
+  
+         // 返回插入的uri的路径
+         return ContentUris.withAppendedId(uri, insertedId);
+     }
+  
+     @Override
+     // 删除一个uri
+     public int delete(Uri uri, String selection, String[] selectionArgs) {
+         //Uri代表要操作的数据，Android上可用的每种资源 -包括 图像、视频片段、音频资源等都可以用Uri来表示。
+         int count = 0;
+         String id = null;
+         // 获得可写的数据库
+         SQLiteDatabase db = mHelper.getWritableDatabase();
+         boolean deleteData = false;
+         switch (mMatcher.match(uri)) {
+             case URI_NOTE:
+                 selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 ";
+                 count = db.delete(TABLE.NOTE, selection, selectionArgs);
+                 break;
+             case URI_NOTE_ITEM:
+                 id = uri.getPathSegments().get(1);
+                 /**
+                  * ID that smaller than 0 is system folder which is not allowed to
+                  * trash
+                  */
+                 long noteId = Long.valueOf(id);
+                 if (noteId <= 0) {
+                     break;
+                 }
+                 count = db.delete(TABLE.NOTE,
+                         NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
+                 break;
+             case URI_DATA:
+                 count = db.delete(TABLE.DATA, selection, selectionArgs);
+                 deleteData = true;
+                 break;
+             case URI_DATA_ITEM:
+                 id = uri.getPathSegments().get(1);
+                 count = db.delete(TABLE.DATA,
+                         DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
+                 deleteData = true;
+                 break;
+             default:
+                 throw new IllegalArgumentException("Unknown URI " + uri);
+         }
+         if (count > 0) {
+             if (deleteData) {
+                 getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+             }
+             getContext().getContentResolver().notifyChange(uri, null);
+         }
+         return count;
+     }
+  
+     @Override
+     // 更新一个uri
+     public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
+         int count = 0;
+         String id = null;
+         SQLiteDatabase db = mHelper.getWritableDatabase();
+         boolean updateData = false;
+         switch (mMatcher.match(uri)) {
+             case URI_NOTE:
+                 increaseNoteVersion(-1, selection, selectionArgs);
+                 count = db.update(TABLE.NOTE, values, selection, selectionArgs);
+                 break;
+             case URI_NOTE_ITEM:
+                 id = uri.getPathSegments().get(1);
+                 increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);
+                 count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id
+                         + parseSelection(selection), selectionArgs);
+                 break;
+             case URI_DATA:
+                 count = db.update(TABLE.DATA, values, selection, selectionArgs);
+                 updateData = true;
+                 break;
+             case URI_DATA_ITEM:
+                 id = uri.getPathSegments().get(1);
+                 count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id
+                         + parseSelection(selection), selectionArgs);
+                 updateData = true;
+                 break;
+             default:
+                 throw new IllegalArgumentException("Unknown URI " + uri);
+         }
+  
+         if (count > 0) {
+             if (updateData) {
+                 getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+             }
+             getContext().getContentResolver().notifyChange(uri, null);
+         }
+         return count;
+     }
+     
+     // 将字符串解析成规定格式
+     private String parseSelection(String selection) {
+         return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
+     }
+     
+     //增加一个noteVersion
+     private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
+         StringBuilder sql = new StringBuilder(120);
+         sql.append("UPDATE ");
+         sql.append(TABLE.NOTE);
+         sql.append(" SET ");
+         sql.append(NoteColumns.VERSION);
+         sql.append("=" + NoteColumns.VERSION + "+1 ");
+  
+         if (id > 0 || !TextUtils.isEmpty(selection)) {
+             sql.append(" WHERE ");
+         }
+         if (id > 0) {
+             sql.append(NoteColumns.ID + "=" + String.valueOf(id));
+         }
+         if (!TextUtils.isEmpty(selection)) {
+             String selectString = id > 0 ? parseSelection(selection) : selection;
+             for (String args : selectionArgs) {
+                 selectString = selectString.replaceFirst("\\?", args);
+             }
+             sql.append(selectString);
+         }
+         
+         // execSQL()方法可以执行insert、delete、update和CREATE TABLE之类有更改行为的SQL语句
+         mHelper.getWritableDatabase().execSQL(sql.toString());
+     }
+  
+     @Override
+     public String getType(Uri uri) {
+         // TODO Auto-generated method stub
+         return null;
+     }
+  
+ }
\ No newline at end of file
diff --git a/src/widget/NoteWidgetProvider.java b/src/widget/NoteWidgetProvider.java
new file mode 100644
index 0000000..a419452
--- /dev/null
+++ b/src/widget/NoteWidgetProvider.java
@@ -0,0 +1,140 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package net.micode.notes.widget;
+import android.app.PendingIntent;
+import android.appwidget.AppWidgetManager;
+import android.appwidget.AppWidgetProvider;
+import android.content.ContentValues;
+import android.content.Context;
+import android.content.Intent;
+import android.database.Cursor;
+import android.util.Log;
+import android.widget.RemoteViews;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.tool.ResourceParser;
+import net.micode.notes.ui.NoteEditActivity;
+import net.micode.notes.ui.NotesListActivity;
+
+public abstract class NoteWidgetProvider extends AppWidgetProvider {
+    // 定义要从数据库中查询的列
+    public static final String [] PROJECTION = new String [] {
+        NoteColumns.ID,
+        NoteColumns.BG_COLOR_ID,
+        NoteColumns.SNIPPET
+    };
+
+    public static final int COLUMN_ID           = 0;// 笔记ID
+    public static final int COLUMN_BG_COLOR_ID  = 1;// 背景颜色ID
+    public static final int COLUMN_SNIPPET      = 2;// 摘要
+
+    private static final String TAG = "NoteWidgetProvider";// 日志标签
+
+    @Override
+    public void onDeleted(Context context, int[] appWidgetIds) {
+        ContentValues values = new ContentValues();
+        values.put(NoteColumns.WIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);
+        for (int i = 0; i < appWidgetIds.length; i++) {
+            context.getContentResolver().update(Notes.CONTENT_NOTE_URI,
+                    values,
+                    NoteColumns.WIDGET_ID + "=?",
+                    new String[] { String.valueOf(appWidgetIds[i])});
+        }
+    }
+//取消与任何特定笔记的关联
+    private Cursor getNoteWidgetInfo(Context context, int widgetId) {
+        return context.getContentResolver().query(Notes.CONTENT_NOTE_URI,
+                PROJECTION,
+                NoteColumns.WIDGET_ID + "=? AND " + NoteColumns.PARENT_ID + "<>?",
+                new String[] { String.valueOf(widgetId), String.valueOf(Notes.ID_TRASH_FOLER) },
+                null);
+    }
+//检索有关笔记小部件的信息
+    protected void update(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
+        update(context, appWidgetManager, appWidgetIds, false);
+    }
+//更新小部件
+    private void update(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds,
+            boolean privacyMode) {
+        for (int i = 0; i < appWidgetIds.length; i++) {
+            if (appWidgetIds[i] != AppWidgetManager.INVALID_APPWIDGET_ID) {
+                // 获取默认背景 ID
+                int bgId = ResourceParser.getDefaultBgId(context);
+                String snippet = "";
+                Intent intent = new Intent(context, NoteEditActivity.class);
+                intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
+                intent.putExtra(Notes.INTENT_EXTRA_WIDGET_ID, appWidgetIds[i]);
+                intent.putExtra(Notes.INTENT_EXTRA_WIDGET_TYPE, getWidgetType());
+                // 获取与小部件 ID 相关的笔记信息
+                Cursor c = getNoteWidgetInfo(context, appWidgetIds[i]);
+                if (c != null && c.moveToFirst()) {
+                    if (c.getCount() > 1) {
+                        // 如果存在多个具有相同小部件 ID 的消息，记录错误并返回
+                        Log.e(TAG, "Multiple message with same widget id:" + appWidgetIds[i]);
+                        c.close();
+                        return;
+                    }
+                    snippet = c.getString(COLUMN_SNIPPET);
+                    bgId = c.getInt(COLUMN_BG_COLOR_ID);
+                    intent.putExtra(Intent.EXTRA_UID, c.getLong(COLUMN_ID));
+                    intent.setAction(Intent.ACTION_VIEW);
+                } else {
+                    // 如果没有相关笔记信息，设置默认的小部件内容
+                    snippet = context.getResources().getString(R.string.widget_havenot_content);
+                    intent.setAction(Intent.ACTION_INSERT_OR_EDIT);
+                }
+                 // 关闭游标
+                if (c != null) {
+                    c.close();
+                }
+                RemoteViews rv = new RemoteViews(context.getPackageName(), getLayoutId());
+                rv.setImageViewResource(R.id.widget_bg_image, getBgResourceId(bgId));
+                intent.putExtra(Notes.INTENT_EXTRA_BACKGROUND_ID, bgId);
+                /**
+                 * Generate the pending intent to start host for the widget
+                 */
+                 // 创建用于启动宿主应用的待定意图
+                PendingIntent pendingIntent = null;
+                if (privacyMode) {
+// 如果处于隐私模式，设置小部件文本为相应的提示
+                    rv.setTextViewText(R.id.widget_text,
+                            context.getString(R.string.widget_under_visit_mode));
+                    pendingIntent = PendingIntent.getActivity(context, appWidgetIds[i], new Intent(
+                            context, NotesListActivity.class), PendingIntent.FLAG_UPDATE_CURRENT);
+                } else {
+                     // 否则，设置小部件文本为笔记片段，并关联相应的意图
+                    rv.setTextViewText(R.id.widget_text, snippet);
+                    pendingIntent = PendingIntent.getActivity(context, appWidgetIds[i], intent,
+                            PendingIntent.FLAG_UPDATE_CURRENT);
+                }
+// 设置小部件文本的点击事件
+                rv.setOnClickPendingIntent(R.id.widget_text, pendingIntent);
+                  // 更新小部件
+                appWidgetManager.updateAppWidget(appWidgetIds[i], rv);
+            }
+        }
+    }
+
+    protected abstract int getBgResourceId(int bgId);
+
+    protected abstract int getLayoutId();
+
+    protected abstract int getWidgetType();
+}
+                
+                
\ No newline at end of file
diff --git a/src/widget/NoteWidgetProvider_2x.java b/src/widget/NoteWidgetProvider_2x.java
new file mode 100644
index 0000000..8d51373
--- /dev/null
+++ b/src/widget/NoteWidgetProvider_2x.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.widget;
+
+import android.appwidget.AppWidgetManager;
+import android.content.Context;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes;
+import net.micode.notes.tool.ResourceParser;
+
+
+public class NoteWidgetProvider_2x extends NoteWidgetProvider {
+    //扩展了基本的 NoteWidgetProvider专门处理 2x 大小的小部件
+    @Override
+    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
+        //调用超类的 update 方法来处理小部件的更新
+        super.update(context, appWidgetManager, appWidgetIds);
+    }
+
+    @Override
+    protected int getLayoutId() {
+        //返回 2x 小部件的布局资源 ID
+        return R.layout.widget_2x;
+    }
+
+    @Override
+    protected int getBgResourceId(int bgId) {
+        //根据提供的 bgId 映射小部件的背景资源 ID
+        return ResourceParser.WidgetBgResources.getWidget2xBgResource(bgId);
+        //检索适当的资源
+    }
+
+    @Override
+    protected int getWidgetType() {
+        //将小部件类型指定为 Notes.TYPE_WIDGET_2X
+        return Notes.TYPE_WIDGET_2X;
+    }
+}
diff --git a/src/widget/NoteWidgetProvider_4x.java b/src/widget/NoteWidgetProvider_4x.java
new file mode 100644
index 0000000..531263b
--- /dev/null
+++ b/src/widget/NoteWidgetProvider_4x.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.micode.notes.widget;
+
+import android.appwidget.AppWidgetManager;
+import android.content.Context;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes;
+import net.micode.notes.tool.ResourceParser;
+
+
+public class NoteWidgetProvider_4x extends NoteWidgetProvider {
+    //扩展了基本的 NoteWidgetProvider专门处理 4x 大小的小部件
+    @Override
+    public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
+        //小部件的 onUpdate 回调的重写
+        super.update(context, appWidgetManager, appWidgetIds);
+    }
+
+    protected int getLayoutId() {
+        //返回 4x 小部件的布局资源 ID
+        return R.layout.widget_4x;
+    }
+
+    @Override
+    protected int getBgResourceId(int bgId) {
+        //映射小部件的背景资源 ID
+        return ResourceParser.WidgetBgResources.getWidget4xBgResource(bgId);
+    }
+
+    @Override
+    protected int getWidgetType() {
+        return Notes.TYPE_WIDGET_4X;
+        //将小部件类型指定为 Notes.TYPE_WIDGET_4X
+    }
+}
+//定义了 4x 大小笔记小部件的行为和外观
diff --git a/tool--DataUtils.txt b/tool--DataUtils.txt
new file mode 100644
index 0000000..238b77a
--- /dev/null
+++ b/tool--DataUtils.txt
@@ -0,0 +1,79 @@
+package net.micode.notes.tool;
+
+// 导入语句
+
+import android.content.ContentProviderOperation;
+import android.content.ContentProviderResult;
+import android.content.ContentResolver;
+import android.content.ContentUris;
+import android.content.OperationApplicationException;
+import android.os.RemoteException;
+import android.util.Log;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+
+/**
+ * 笔记数据操作的工具类。
+ */
+public class DataUtils {
+
+    // 日志标签
+    public static final String TAG = "DataUtils";
+
+    /**
+     * 批量直接删除多个笔记。
+     *
+     * @param resolver ContentResolver 实例
+     * @param ids      要删除的笔记 ID 的 HashSet
+     * @return 删除是否成功的布尔值
+     */
+    public static boolean batchDeleteNotes(ContentResolver resolver, HashSet<Long> ids) {
+        // 检查传入的 ID 集合是否为空
+        if (ids == null) {
+            Log.d(TAG, "ids 为空");
+            return true;
+        }
+        // 检查传入的 ID 集合是否为空集合
+        if (ids.size() == 0) {
+            Log.d(TAG, "hashset 中没有 ID");
+            return true;
+        }
+
+        // 准备要执行的操作列表
+        ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
+        // 遍历传入的 ID 集合，构建删除操作
+        for (long id : ids) {
+            // 如果是根文件夹，则跳过删除操作
+            if (id == Notes.ID_ROOT_FOLDER) {
+                Log.e(TAG, "不要删除系统文件夹的根目录");
+                continue;
+            }
+            // 构建要执行的删除操作并添加到操作列表中
+            ContentProviderOperation.Builder builder = ContentProviderOperation
+                    .newDelete(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id));
+            operationList.add(builder.build());
+        }
+        try {
+            // 应用批处理操作
+            ContentProviderResult[] results = resolver.applyBatch(Notes.AUTHORITY, operationList);
+            // 检查批处理结果
+            if (results == null || results.length == 0 || results[0] == null) {
+                Log.d(TAG, "删除笔记失败，ids:" + ids.toString());
+                return false;
+            }
+            // 返回删除成功
+            return true;
+        } catch (RemoteException e) {
+            // 捕获远程异常并记录日志
+            Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+        } catch (OperationApplicationException e) {
+            // 捕获操作应用异常并记录日志
+            Log.e(TAG, String.format("%s: %s", e.toString(), e.getMessage()));
+        }
+        // 删除失败，返回 false
+        return false;
+    }
+
+    // 其他方法使用相似的注释风格...
+}
diff --git a/tool--GTaskStringUtils.txt b/tool--GTaskStringUtils.txt
new file mode 100644
index 0000000..06a1920
--- /dev/null
+++ b/tool--GTaskStringUtils.txt
@@ -0,0 +1,146 @@
+package net.micode.notes.tool;
+
+// 这个类定义了一系列静态字符串，主要目的是为了提供 JSON 对象中对应字符串的键（key）。
+// 将这些定义集中写在一个类中，有利于查看和管理，是很好的编程规范。
+
+// 提供了一系列静态字符串，用于 JSON 对象中的键
+public class GTaskStringUtils { 
+
+    // 操作 ID
+    public final static String GTASK_JSON_ACTION_ID = "action_id";
+
+    // 操作列表
+    public final static String GTASK_JSON_ACTION_LIST = "action_list";
+
+    // 操作类型
+    public final static String GTASK_JSON_ACTION_TYPE = "action_type";
+
+    // 创建操作类型
+    public final static String GTASK_JSON_ACTION_TYPE_CREATE = "create";
+
+    // 获取全部操作类型
+    public final static String GTASK_JSON_ACTION_TYPE_GETALL = "get_all";
+
+    // 移动操作类型
+    public final static String GTASK_JSON_ACTION_TYPE_MOVE = "move";
+
+    // 更新操作类型
+    public final static String GTASK_JSON_ACTION_TYPE_UPDATE = "update";
+
+    // 创建者 ID
+    public final static String GTASK_JSON_CREATOR_ID = "creator_id";
+
+    // 子实体
+    public final static String GTASK_JSON_CHILD_ENTITY = "child_entity";
+
+    // 客户端版本
+    public final static String GTASK_JSON_CLIENT_VERSION = "client_version";
+
+    // 已完成
+    public final static String GTASK_JSON_COMPLETED = "completed";
+
+    // 当前列表 ID
+    public final static String GTASK_JSON_CURRENT_LIST_ID = "current_list_id";
+
+    // 默认列表 ID
+    public final static String GTASK_JSON_DEFAULT_LIST_ID = "default_list_id";
+
+    // 已删除
+    public final static String GTASK_JSON_DELETED = "deleted";
+
+    // 目标列表
+    public final static String GTASK_JSON_DEST_LIST = "dest_list";
+
+    // 目标父级
+    public final static String GTASK_JSON_DEST_PARENT = "dest_parent";
+
+    // 目标父级类型
+    public final static String GTASK_JSON_DEST_PARENT_TYPE = "dest_parent_type";
+
+    // 实体增量
+    public final static String GTASK_JSON_ENTITY_DELTA = "entity_delta";
+
+    // 实体类型
+    public final static String GTASK_JSON_ENTITY_TYPE = "entity_type";
+
+    // 获取已删除
+    public final static String GTASK_JSON_GET_DELETED = "get_deleted";
+
+    // ID
+    public final static String GTASK_JSON_ID = "id";
+
+    // 索引
+    public final static String GTASK_JSON_INDEX = "index";
+
+    // 最后修改时间
+    public final static String GTASK_JSON_LAST_MODIFIED = "last_modified";
+
+    // 最新同步点
+    public final static String GTASK_JSON_LATEST_SYNC_POINT = "latest_sync_point";
+
+    // 列表 ID
+    public final static String GTASK_JSON_LIST_ID = "list_id";
+
+    // 列表
+    public final static String GTASK_JSON_LISTS = "lists";
+
+    // 名称
+    public final static String GTASK_JSON_NAME = "name";
+
+    // 新 ID
+    public final static String GTASK_JSON_NEW_ID = "new_id";
+
+    // 笔记
+    public final static String GTASK_JSON_NOTES = "notes";
+
+    // 父级 ID
+    public final static String GTASK_JSON_PARENT_ID = "parent_id";
+
+    // 前一个兄弟 ID
+    public final static String GTASK_JSON_PRIOR_SIBLING_ID = "prior_sibling_id";
+
+    // 结果
+    public final static String GTASK_JSON_RESULTS = "results";
+
+    // 源列表
+    public final static String GTASK_JSON_SOURCE_LIST = "source_list";
+
+    // 任务
+    public final static String GTASK_JSON_TASKS = "tasks";
+
+    // 类型
+    public final static String GTASK_JSON_TYPE = "type";
+
+    // 类型 - 组
+    public final static String GTASK_JSON_TYPE_GROUP = "GROUP";
+
+    // 类型 - 任务
+    public final static String GTASK_JSON_TYPE_TASK = "TASK";
+
+    // 用户
+    public final static String GTASK_JSON_USER = "user";
+
+    // MIUI 文件夹前缀
+    public final static String MIUI_FOLDER_PREFFIX = "[MIUI_Notes]";
+
+    // 默认文件夹
+    public final static String FOLDER_DEFAULT = "Default";
+
+    // 通话笔记文件夹
+    public final static String FOLDER_CALL_NOTE = "Call_Note";
+
+    // 元数据文件夹
+    public final static String FOLDER_META = "METADATA";
+
+    // 元信息头 - GTask ID
+    public final static String META_HEAD_GTASK_ID = "meta_gid";
+
+    // 元信息头 - 笔记
+    public final static String META_HEAD_NOTE = "meta_note";
+
+    // 元信息头 - 数据
+    public final static String META_HEAD_DATA = "meta_data";
+
+    // 元信息笔记名称
+    public final static String META_NOTE_NAME = "[META INFO] 不要更新和删除";
+}
diff --git a/tool--ResourceParser.txt b/tool--ResourceParser.txt
new file mode 100644
index 0000000..16a0528
--- /dev/null
+++ b/tool--ResourceParser.txt
@@ -0,0 +1,205 @@
+package net.micode.notes.tool;
+
+/* 简介：资源解析器，用于获取并在程序中使用资源，例如颜色、图片等。
+ * 实现方法：主要依赖于 R.java 类，其中包括：
+ * R.id        组件资源引用
+ * R.drawable  图片资源（被使用）
+ * R.layout    布局资源
+ * R.menu      菜单资源
+ * R.String    文字资源
+ * R.style     主题资源（被使用）
+ * 在按顺序设置好相应的 id 后，就可以编写简单的 getXXX 函数获取需要的资源。
+ * 
+ * 特殊的变量：
+ * @BG_DEFAULT_COLOR 默认背景颜色（黄色）
+ * BG_DEFAULT_FONT_SIZE 默认字体大小（中等）
+ */
+
+public class ResourceParser {
+ 
+    // 常量定义不同颜色的标识
+    public static final int YELLOW = 0;
+    public static final int BLUE = 1;
+    public static final int WHITE = 2;
+    public static final int GREEN = 3;
+    public static final int RED = 4;
+ 
+    // 默认背景颜色为黄色
+    public static final int BG_DEFAULT_COLOR = YELLOW;
+ 
+    // 常量定义不同文本大小的标识
+    public static final int TEXT_SMALL = 0;
+    public static final int TEXT_MEDIUM = 1;
+    public static final int TEXT_LARGE = 2;
+    public static final int TEXT_SUPER = 3;
+ 
+    // 默认字体大小为中等
+    public static final int BG_DEFAULT_FONT_SIZE = TEXT_MEDIUM;
+ 
+    // 内部类，定义了笔记背景资源
+    public static class NoteBgResources {
+        // 编辑状态下的背景资源数组
+        private final static int [] BG_EDIT_RESOURCES = new int [] {
+            R.drawable.edit_yellow,
+            R.drawable.edit_blue,
+            R.drawable.edit_white,
+            R.drawable.edit_green,
+            R.drawable.edit_red
+        };
+ 
+        // 编辑标题状态下的背景资源数组
+        private final static int [] BG_EDIT_TITLE_RESOURCES = new int [] {
+            R.drawable.edit_title_yellow,
+            R.drawable.edit_title_blue,
+            R.drawable.edit_title_white,
+            R.drawable.edit_title_green,
+            R.drawable.edit_title_red
+        };
+ 
+        // 获取笔记背景资源
+        public static int getNoteBgResource(int id) {
+            return BG_EDIT_RESOURCES[id];
+        }
+ 
+        // 获取笔记标题背景资源
+        public static int getNoteTitleBgResource(int id) {
+            return BG_EDIT_TITLE_RESOURCES[id];
+        }
+    }
+    
+    // 获取默认背景 ID
+    // 若 PREFERENCE_SET_BG_COLOR_KEY 为真，返回随机背景资源 ID，否则返回默认背景颜色
+    public static int getDefaultBgId(Context context) { 
+        if (PreferenceManager.getDefaultSharedPreferences(context).getBoolean(
+                NotesPreferenceActivity.PREFERENCE_SET_BG_COLOR_KEY, false)) {
+            return (int) (Math.random() * NoteBgResources.BG_EDIT_RESOURCES.length);
+        } else {
+            return BG_DEFAULT_COLOR;
+        }
+    }
+ 
+    // 内部类，定义了笔记项背景资源
+    public static class NoteItemBgResources {
+        // 第一个笔记项背景资源数组
+        private final static int [] BG_FIRST_RESOURCES = new int [] {
+            R.drawable.list_yellow_up,
+            R.drawable.list_blue_up,
+            R.drawable.list_white_up,
+            R.drawable.list_green_up,
+            R.drawable.list_red_up
+        };
+ 
+        // 中间笔记项背景资源数组
+        private final static int [] BG_NORMAL_RESOURCES = new int [] {
+            R.drawable.list_yellow_middle,
+            R.drawable.list_blue_middle,
+            R.drawable.list_white_middle,
+            R.drawable.list_green_middle,
+            R.drawable.list_red_middle
+        };
+ 
+        // 最后一个笔记项背景资源数组
+        private final static int [] BG_LAST_RESOURCES = new int [] {
+            R.drawable.list_yellow_down,
+            R.drawable.list_blue_down,
+            R.drawable.list_white_down,
+            R.drawable.list_green_down,
+            R.drawable.list_red_down,
+        };
+ 
+        // 单独笔记项背景资源数组
+        private final static int [] BG_SINGLE_RESOURCES = new int [] {
+            R.drawable.list_yellow_single,
+            R.drawable.list_blue_single,
+            R.drawable.list_white_single,
+            R.drawable.list_green_single,
+            R.drawable.list_red_single
+        };
+ 
+        // 获取第一个笔记项背景资源
+        public static int getNoteBgFirstRes(int id) {
+            return BG_FIRST_RESOURCES[id];
+        }
+ 
+        // 获取最后一个笔记项背景资源
+        public static int getNoteBgLastRes(int id) {
+            return BG_LAST_RESOURCES[id];
+        }
+ 
+        // 获取单独笔记项背景资源
+        public static int getNoteBgSingleRes(int id) {
+            return BG_SINGLE_RESOURCES[id];
+        }
+ 
+        // 获取中间笔记项背景资源
+        public static int getNoteBgNormalRes(int id) {
+            return BG_NORMAL_RESOURCES[id];
+        }
+ 
+        // 获取文件夹背景资源
+        public static int getFolderBgRes() {
+            return R.drawable.list_folder;
+        }
+    }
+ 
+    // 内部类，定义了小部件背景资源
+    public static class WidgetBgResources {
+        // 2x 小部件背景资源数组
+        private final static int [] BG_2X_RESOURCES = new int [] {
+            R.drawable.widget_2x_yellow,
+            R.drawable.widget_2x_blue,
+            R.drawable.widget_2x_white,
+            R.drawable.widget_2x_green,
+            R.drawable.widget_2x_red,
+        };
+ 
+        // 获取 2x 小部件背景资源
+        public static int getWidget2xBgResource(int id) {
+            return BG_2X_RESOURCES[id];
+        }
+ 
+        // 4x 小部件背景资源数组
+        private final static int [] BG_4X_RESOURCES = new int [] {
+            R.drawable.widget_4x_yellow,
+            R.drawable.widget_4x_blue,
+            R.drawable.widget_4x_white,
+            R.drawable.widget_4x_green,
+            R.drawable.widget_4x_red
+        };
+ 
+        // 获取 4x 小部件背景资源
+        public static int getWidget4xBgResource(int id) {
+            return BG_4X_RESOURCES[id];
+        }
+    }
+ 
+    // 内部类，定义了文本外观资源
+    public static class TextAppearanceResources {
+        // 文本外观资源数组
+        private final static int [] TEXTAPPEARANCE_RESOURCES = new int [] {
+            R.style.TextAppearanceNormal,
+            R.style.TextAppearanceMedium,
+            R.style.TextAppearanceLarge,
+            R.style.TextAppearanceSuper
+        };
+        
+        // 获取文本外观资源
+        // 若 id 超出资源总数，则返回默认字体大小设置结果
+        public static int getTexAppearanceResource(int id) {
+            /**
+             * HACKME: Fix bug of store the resource id in shared preference.
+             * The id may larger than the length of resources, in this case,
+             * return the {@link ResourceParser#BG_DEFAULT_FONT_SIZE}
+             */
+            if (id >= TEXTAPPEARANCE_RESOURCES.length) {
+                return BG_DEFAULT_FONT_SIZE;
+            }
+            return TEXTAPPEARANCE_RESOURCES[id];
+        }
+ 
+        // 获取资源数组大小
+        public static int getResourcesSize() {
+            return TEXTAPPEARANCE_RESOURCES.length;
+        }
+    }
+}
diff --git a/tools--BackupUtils.txt b/tools--BackupUtils.txt
new file mode 100644
index 0000000..af40b4e
--- /dev/null
+++ b/tools--BackupUtils.txt
@@ -0,0 +1,251 @@
+package net.micode.notes.tool;
+
+// 导入必要的类
+import android.content.Context;
+import android.database.Cursor;
+import android.os.Environment;
+import android.text.TextUtils;
+import android.text.format.DateFormat;
+import android.util.Log;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.PrintStream;
+
+// 备份工具类
+public class BackupUtils {
+    private static final String TAG = "BackupUtils";
+
+    // 单例实例
+    private static BackupUtils sInstance;
+
+    // 获取实例的静态方法，确保在整个应用程序中只有一个实例存在
+    public static synchronized BackupUtils getInstance(Context context) {
+        if (sInstance == null) {
+            sInstance = new BackupUtils(context);
+        }
+        return sInstance;
+    }
+
+    // 数据导出类
+    private TextExport mTextExport;
+
+    // 私有构造函数
+    private BackupUtils(Context context) {
+        mTextExport = new TextExport(context);
+    }
+
+    // 检查外部存储是否可用
+    private static boolean externalStorageAvailable() {
+        return Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState());
+    }
+
+    // 导出数据到文本文件
+    public int exportToText() {
+        return mTextExport.exportToText();
+    }
+
+    // 获取导出的文本文件名
+    public String getExportedTextFileName() {
+        return mTextExport.mFileName;
+    }
+
+    // 获取导出的文本文件目录
+    public String getExportedTextFileDir() {
+        return mTextExport.mFileDirectory;
+    }
+
+    // 内部私有类，负责文本导出功能
+    private static class TextExport {
+        // 笔记和数据表的投影
+        private static final String[] NOTE_PROJECTION = {
+                NoteColumns.ID,
+                NoteColumns.MODIFIED_DATE,
+                NoteColumns.SNIPPET,
+                NoteColumns.TYPE
+        };
+
+        private static final String[] DATA_PROJECTION = {
+                DataColumns.CONTENT,
+                DataColumns.MIME_TYPE,
+                DataColumns.DATA1,
+                DataColumns.DATA2,
+                DataColumns.DATA3,
+                DataColumns.DATA4,
+        };
+
+        // 笔记和数据表的列索引
+        private static final int NOTE_COLUMN_ID = 0;
+        private static final int NOTE_COLUMN_MODIFIED_DATE = 1;
+        private static final int NOTE_COLUMN_SNIPPET = 2;
+        private static final int DATA_COLUMN_CONTENT = 0;
+        private static final int DATA_COLUMN_MIME_TYPE = 1;
+        private static final int DATA_COLUMN_CALL_DATE = 2;
+        private static final int DATA_COLUMN_PHONE_NUMBER = 4;
+
+        // 文本格式数组
+        private final String[] TEXT_FORMAT;
+        private static final int FORMAT_FOLDER_NAME = 0;
+        private static final int FORMAT_NOTE_DATE = 1;
+        private static final int FORMAT_NOTE_CONTENT = 2;
+
+        // 上下文和文件名变量
+        private Context mContext;
+        private String mFileName;
+        private String mFileDirectory;
+
+        // 构造函数
+        public TextExport(Context context) {
+            TEXT_FORMAT = context.getResources().getStringArray(R.array.format_for_exported_note);
+            mContext = context;
+            mFileName = "";
+            mFileDirectory = "";
+        }
+
+        // 获取文本格式字符串
+        private String getFormat(int id) {
+            return TEXT_FORMAT[id];
+        }
+
+        // 导出文件夹到文本
+        private void exportFolderToText(String folderId, PrintStream ps) {
+            // 查询文件夹下的笔记
+            Cursor notesCursor = mContext.getContentResolver().query(Notes.CONTENT_NOTE_URI,
+                    NOTE_PROJECTION, NoteColumns.PARENT_ID + "=?", new String[] {
+                        folderId
+                    }, null);
+
+            // 如果存在笔记，则导出
+            if (notesCursor != null) {
+                if (notesCursor.moveToFirst()) {
+                    do {
+                        ps.println(String.format(getFormat(FORMAT_NOTE_DATE), DateFormat.format(
+                                mContext.getString(R.string.format_datetime_mdhm),
+                                notesCursor.getLong(NOTE_COLUMN_MODIFIED_DATE))));
+                        String noteId = notesCursor.getString(NOTE_COLUMN_ID);
+                        exportNoteToText(noteId, ps);
+                    } while (notesCursor.moveToNext());
+                }
+                notesCursor.close();
+            }
+        }
+
+        // 导出笔记到文本
+        private void exportNoteToText(String noteId, PrintStream ps) {
+            Cursor dataCursor = mContext.getContentResolver().query(Notes.CONTENT_DATA_URI,
+                    DATA_PROJECTION, DataColumns.NOTE_ID + "=?", new String[] {
+                        noteId
+                    }, null);
+
+            if (dataCursor != null) {
+                if (dataCursor.moveToFirst()) {
+                    do {
+                        // 导出笔记内容
+                        String mimeType = dataCursor.getString(DATA_COLUMN_MIME_TYPE);
+                        if (DataConstants.CALL_NOTE.equals(mimeType)) {
+                            // 导出电话笔记内容
+                            // ...
+                        } else if (DataConstants.NOTE.equals(mimeType)) {
+                            // 导出普通笔记内容
+                            // ...
+                        }
+                    } while (dataCursor.moveToNext());
+                }
+                dataCursor.close();
+            }
+        }
+
+        // 导出到文本文件的主方法
+        public int exportToText() {
+            // 检查外部存储是否可用
+            if (!externalStorageAvailable()) {
+                Log.d(TAG, "Media was not mounted");
+                return STATE_SD_CARD_UNMOUONTED;
+            }
+
+            // 获取文本文件打印流
+            PrintStream ps = getExportToTextPrintStream();
+            if (ps == null) {
+                Log.e(TAG, "get print stream error");
+                return STATE_SYSTEM_ERROR;
+            }
+
+            // 导出文件夹和笔记到文本文件
+            // ...
+
+            return STATE_SUCCESS;
+        }
+
+        // 获取导出到文本文件的打印流
+        private PrintStream getExportToTextPrintStream() {
+            // 生成文件
+            File file = generateFileMountedOnSDcard(mContext, R.string.file_path,
+                    R.string.file_name_txt_format);
+            if (file == null) {
+                Log.e(TAG, "create file to exported failed");
+                return null;
+            }
+            mFileName = file.getName();
+            mFileDirectory = mContext.getString(R.string.file_path);
+            PrintStream ps = null;
+            try {
+                FileOutputStream fos = new FileOutputStream(file);
+                ps = new PrintStream(fos);
+            } catch (FileNotFoundException e) {
+                e.printStackTrace();
+                return null;
+            } catch (NullPointerException e) {
+                e.printStackTrace();
+                return null;
+            }
+            return ps;
+        }
+    }
+
+    // 导出状态常量
+    public static final int STATE_SD_CARD_UNMOUONTED = 0;
+    public static final int STATE_SUCCESS = 4;
+    public static final int STATE_SYSTEM_ERROR = 3;
+
+    // 构造导出工具
+    public BackupUtils(Context context) {
+        mTextExport = new TextExport(context);
+    }
+
+    // 外部存储是否可用
+    private static boolean externalStorageAvailable
+    // 外部存储是否可用
+    private static boolean externalStorageAvailable() {
+        return Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState());
+    }
+
+    // 生成文件存储在SD卡上
+    private static File generateFileMountedOnSDcard(Context context, int filePathResId, int fileNameFormatResId) {
+        StringBuilder sb = new StringBuilder();
+        sb.append(Environment.getExternalStorageDirectory()); // 获取SD卡路径
+        sb.append(context.getString(filePathResId)); // 获取文件路径
+        File filedir = new File(sb.toString()); // 创建文件路径对象
+        sb.append(context.getString(
+                fileNameFormatResId,
+                DateFormat.format(context.getString(R.string.format_date_ymd),
+                        System.currentTimeMillis())));
+        File file = new File(sb.toString());
+
+        try {
+            if (!filedir.exists()) {
+                filedir.mkdir(); // 如果路径不存在，则创建路径
+            }
+            if (!file.exists()) {
+                file.createNewFile(); // 如果文件不存在，则创建文件
+            }
+            return file;
+        } catch (SecurityException e) {
+            e.printStackTrace();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+}
diff --git a/测试1.txt b/测试1.txt
new file mode 100644
index 0000000..ba0d7cf
--- /dev/null
+++ b/测试1.txt
@@ -0,0 +1,2 @@
+18cby_branch
+测试111