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src/data/Contact.java

@@ -1,17 +1,15 @@
 /*
- * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ * 版权所有 (c) 2010-2011, The MiCode 开源社区 (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
+ * 根据 Apache 许可证 2.0 版本授权
+ * 除非遵守许可证，否则不得使用此文件
+ * 您可以在以下网址获取许可证副本：
  *
  *        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.
+ * 除非适用法律要求或书面同意，软件按"原样"分发
+ * 没有任何明示或暗示的担保或条件
+ * 请参阅许可证了解具体的权限和限制
  */
 
 package net.micode.notes.data;
@@ -25,10 +23,21 @@ import android.util.Log;
 
 import java.util.HashMap;
 
+/**
+ * 联系人查询工具类，用于通过电话号码获取联系人信息
+ */
 public class Contact {
+    // 静态联系人缓存，使用HashMap存储电话号码到联系人姓名的映射
+    // 键：电话号码(String)，值：联系人姓名(String)
     private static HashMap<String, String> sContactCache;
+    
+    // 日志标签，用于调试和错误记录
     private static final String TAG = "Contact";
 
+    // 联系人查询的选择条件(WHERE子句)
+    // 1. 使用PHONE_NUMBERS_EQUAL函数比较电话号码
+    // 2. 限制MIME类型为电话类型
+    // 3. 通过phone_lookup表提高查询效率
     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 "
@@ -36,38 +45,65 @@ public class Contact {
             + " FROM phone_lookup"
             + " WHERE min_match = '+')";
 
+    /**
+     * 根据电话号码获取联系人姓名
+     * 
+     * @param context Android上下文对象，用于访问ContentResolver
+     * @param phoneNumber 要查询的电话号码
+     * @return 联系人姓名，如果未找到则返回null
+     */
     public static String getContact(Context context, String phoneNumber) {
+        // 初始化缓存(懒加载模式)
         if(sContactCache == null) {
             sContactCache = new HashMap<String, String>();
         }
 
+        // 首先检查缓存中是否已有该号码的查询结果
         if(sContactCache.containsKey(phoneNumber)) {
-            return sContactCache.get(phoneNumber);
+            return sContactCache.get(phoneNumber); // 命中缓存直接返回
         }
 
+        // 准备查询条件：
+        // 1. 将选择语句中的"+"替换为电话号码的最小匹配长度
+        // 2. PhoneNumberUtils.toCallerIDMinMatch()方法会根据号码格式返回合适的匹配长度
         String selection = CALLER_ID_SELECTION.replace("+",
                 PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
+        
+        // 执行内容提供器查询：
+        // 1. 查询URI: Data.CONTENT_URI (联系人数据)
+        // 2. 只查询DISPLAY_NAME(显示名称)列
+        // 3. 使用上面构建的选择条件
+        // 4. 查询参数为phoneNumber
+        // 5. 不指定排序方式
         Cursor cursor = context.getContentResolver().query(
-                Data.CONTENT_URI,
-                new String [] { Phone.DISPLAY_NAME },
-                selection,
-                new String[] { phoneNumber },
-                null);
+                Data.CONTENT_URI,                   // 联系人数据URI
+                new String [] { Phone.DISPLAY_NAME }, // 要查询的列
+                selection,                          // WHERE条件
+                new String[] { phoneNumber },       // WHERE参数
+                null);                             // 排序方式
 
+        // 处理查询结果
         if (cursor != null && cursor.moveToFirst()) {
             try {
+                // 获取第一行第一列的数据(联系人姓名)
                 String name = cursor.getString(0);
+                
+                // 将结果存入缓存以备后续使用
                 sContactCache.put(phoneNumber, name);
+                
                 return name;
             } catch (IndexOutOfBoundsException e) {
-                Log.e(TAG, " Cursor get string error " + e.toString());
+                // 处理可能的数组越界异常
+                Log.e(TAG, "获取Cursor字符串时出错：" + e.toString());
                 return null;
             } finally {
+                // 确保关闭Cursor释放资源
                 cursor.close();
             }
         } else {
-            Log.d(TAG, "No contact matched with number:" + phoneNumber);
+            // 没有找到匹配的联系人记录
+            Log.d(TAG, "没有找到匹配号码的联系人：" + phoneNumber);
             return null;
         }
     }
-}
+}

src/data/Notes.java

@@ -1,279 +1,292 @@
 /*
- * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ * 版权所有 (c) 2010-2011, The MiCode 开源社区 (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
+ * 根据 Apache 许可证 2.0 版本授权
+ * 除非遵守许可证要求，否则不得使用此文件
+ * 您可以在以下网址获取许可证副本：
  *
  *        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.
+ * 除非适用法律要求或书面同意，软件按"原样"分发
+ * 没有任何明示或暗示的担保或条件
+ * 请参阅许可证了解具体权限和限制
  */
 
 package net.micode.notes.data;
 
 import android.net.Uri;
+
+/**
+ * 便签应用的核心常量定义类
+ * 包含URI定义、类型常量、数据列定义等内容
+ */
 public class Notes {
+    // 内容提供器的授权标识
     public static final String AUTHORITY = "micode_notes";
+    
+    // 日志标签
     public static final String TAG = "Notes";
-    public static final int TYPE_NOTE     = 0;
-    public static final int TYPE_FOLDER   = 1;
-    public static final int TYPE_SYSTEM   = 2;
+    
+    // 笔记类型常量
+    public static final int TYPE_NOTE     = 0;   // 普通笔记
+    public static final int TYPE_FOLDER   = 1;   // 文件夹
+    public static final int TYPE_SYSTEM   = 2;   // 系统文件夹
 
     /**
-     * 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
+     * 系统文件夹ID定义：
+     * {@link Notes#ID_ROOT_FOLDER} 根文件夹（默认文件夹）
+     * {@link Notes#ID_TEMPARAY_FOLDER} 临时文件夹（存放未分类笔记）
+     * {@link Notes#ID_CALL_RECORD_FOLDER} 通话记录文件夹
      */
-    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 final int ID_ROOT_FOLDER = 0;           // 根文件夹ID
+    public static final int ID_TEMPARAY_FOLDER = -1;      // 临时文件夹ID
+    public static final int ID_CALL_RECORD_FOLDER = -2;   // 通话记录文件夹ID
+    public static final int ID_TRASH_FOLER = -3;          // 回收站文件夹ID
+
+    // Intent附加数据键名常量
+    public static final String INTENT_EXTRA_ALERT_DATE = "net.micode.notes.alert_date";          // 提醒日期
+    public static final String INTENT_EXTRA_BACKGROUND_ID = "net.micode.notes.background_color_id"; // 背景颜色ID
+    public static final String INTENT_EXTRA_WIDGET_ID = "net.micode.notes.widget_id";            // 桌面小部件ID
+    public static final String INTENT_EXTRA_WIDGET_TYPE = "net.micode.notes.widget_type";        // 小部件类型
+    public static final String INTENT_EXTRA_FOLDER_ID = "net.micode.notes.folder_id";            // 文件夹ID
+    public static final String INTENT_EXTRA_CALL_DATE = "net.micode.notes.call_date";             // 通话日期
+
+    // 桌面小部件类型常量
+    public static final int TYPE_WIDGET_INVALIDE = -1;    // 无效小部件
+    public static final int TYPE_WIDGET_2X = 0;           // 2x大小小部件
+    public static final int TYPE_WIDGET_4X = 1;           // 4x大小小部件
 
+    /**
+     * 数据内容类型常量定义
+     */
     public static class DataConstants {
-        public static final String NOTE = TextNote.CONTENT_ITEM_TYPE;
-        public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE;
+        public static final String NOTE = TextNote.CONTENT_ITEM_TYPE;      // 普通笔记类型
+        public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE; // 通话笔记类型
     }
 
-    /**
-     * Uri to query all notes and folders
-     */
-    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
+    // 内容URI定义
+    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");  // 笔记查询URI
+    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");  // 数据查询URI
 
     /**
-     * Uri to query data
+     * 笔记数据表列名定义接口
      */
-    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
-
     public interface NoteColumns {
         /**
-         * The unique ID for a row
-         * <P> Type: INTEGER (long) </P>
+         * 行唯一ID
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String ID = "_id";
 
         /**
-         * The parent's id for note or folder
-         * <P> Type: INTEGER (long) </P>
+         * 父项ID（用于笔记或文件夹的层级关系）
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String PARENT_ID = "parent_id";
 
         /**
-         * Created data for note or folder
-         * <P> Type: INTEGER (long) </P>
+         * 创建日期
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String CREATED_DATE = "created_date";
 
         /**
-         * Latest modified date
-         * <P> Type: INTEGER (long) </P>
+         * 最后修改日期
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String MODIFIED_DATE = "modified_date";
 
-
         /**
-         * Alert date
-         * <P> Type: INTEGER (long) </P>
+         * 提醒日期
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String ALERTED_DATE = "alert_date";
 
         /**
-         * Folder's name or text content of note
-         * <P> Type: TEXT </P>
+         * 文件夹名称或笔记内容摘要
+         * <P> 类型: TEXT </P>
          */
         public static final String SNIPPET = "snippet";
 
         /**
-         * Note's widget id
-         * <P> Type: INTEGER (long) </P>
+         * 关联的小部件ID
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String WIDGET_ID = "widget_id";
 
         /**
-         * Note's widget type
-         * <P> Type: INTEGER (long) </P>
+         * 小部件类型
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String WIDGET_TYPE = "widget_type";
 
         /**
-         * Note's background color's id
-         * <P> Type: INTEGER (long) </P>
+         * 背景颜色ID
+         * <P> 类型: 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>
+         * 是否有附件（0-无，1-有）
+         * <P> 类型: INTEGER </P>
          */
         public static final String HAS_ATTACHMENT = "has_attachment";
 
         /**
-         * Folder's count of notes
-         * <P> Type: INTEGER (long) </P>
+         * 文件夹中的笔记数量
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String NOTES_COUNT = "notes_count";
 
         /**
-         * The file type: folder or note
-         * <P> Type: INTEGER </P>
+         * 类型标识（笔记/文件夹/系统文件夹）
+         * <P> 类型: INTEGER </P>
          */
         public static final String TYPE = "type";
 
         /**
-         * The last sync id
-         * <P> Type: INTEGER (long) </P>
+         * 同步ID（用于数据同步）
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String SYNC_ID = "sync_id";
 
         /**
-         * Sign to indicate local modified or not
-         * <P> Type: INTEGER </P>
+         * 本地修改标记（0-未修改，1-已修改）
+         * <P> 类型: INTEGER </P>
          */
         public static final String LOCAL_MODIFIED = "local_modified";
 
         /**
-         * Original parent id before moving into temporary folder
-         * <P> Type : INTEGER </P>
+         * 原始父ID（移动前的位置）
+         * <P> 类型: INTEGER </P>
          */
         public static final String ORIGIN_PARENT_ID = "origin_parent_id";
 
         /**
-         * The gtask id
-         * <P> Type : TEXT </P>
+         * Google任务ID（用于与Google Tasks同步）
+         * <P> 类型: TEXT </P>
          */
         public static final String GTASK_ID = "gtask_id";
 
         /**
-         * The version code
-         * <P> Type : INTEGER (long) </P>
+         * 数据版本号
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String VERSION = "version";
     }
 
+    /**
+     * 数据表列名定义接口
+     */
     public interface DataColumns {
         /**
-         * The unique ID for a row
-         * <P> Type: INTEGER (long) </P>
+         * 行唯一ID
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String ID = "_id";
 
         /**
-         * The MIME type of the item represented by this row.
-         * <P> Type: Text </P>
+         * MIME类型标识
+         * <P> 类型: 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>
+         * 关联的笔记ID
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String NOTE_ID = "note_id";
 
         /**
-         * Created data for note or folder
-         * <P> Type: INTEGER (long) </P>
+         * 创建日期
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String CREATED_DATE = "created_date";
 
         /**
-         * Latest modified date
-         * <P> Type: INTEGER (long) </P>
+         * 最后修改日期
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String MODIFIED_DATE = "modified_date";
 
         /**
-         * Data's content
-         * <P> Type: TEXT </P>
+         * 数据内容
+         * <P> 类型: 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>
+         * 通用数据列1，具体含义由MIME_TYPE决定（通常用于整数类型）
+         * <P> 类型: 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>
+         * 通用数据列2，具体含义由MIME_TYPE决定（通常用于整数类型）
+         * <P> 类型: 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>
+         * 通用数据列3，具体含义由MIME_TYPE决定（通常用于文本类型）
+         * <P> 类型: 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>
+         * 通用数据列4，具体含义由MIME_TYPE决定（通常用于文本类型）
+         * <P> 类型: 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>
+         * 通用数据列5，具体含义由MIME_TYPE决定（通常用于文本类型）
+         * <P> 类型: TEXT </P>
          */
         public static final String DATA5 = "data5";
     }
 
+    /**
+     * 文本笔记数据定义
+     */
     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>
+         * 模式标识（0-普通模式，1-清单模式）
+         * <P> 类型: INTEGER </P>
          */
         public static final String MODE = DATA1;
 
-        public static final int MODE_CHECK_LIST = 1;
+        public static final int MODE_CHECK_LIST = 1;  // 清单模式
 
-        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";
+        // MIME类型定义
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/text_note";      // 多项目类型
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note"; // 单项目类型
 
+        // 内容URI
         public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");
     }
 
+    /**
+     * 通话记录笔记数据定义
+     */
     public static final class CallNote implements DataColumns {
         /**
-         * Call date for this record
-         * <P> Type: INTEGER (long) </P>
+         * 通话日期
+         * <P> 类型: INTEGER (long) </P>
          */
         public static final String CALL_DATE = DATA1;
 
         /**
-         * Phone number for this record
-         * <P> Type: TEXT </P>
+         * 电话号码
+         * <P> 类型: 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";
+        // MIME类型定义
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/call_note";      // 多项目类型
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note"; // 单项目类型
 
+        // 内容URI
         public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note");
     }
-}
+}

src/data/NotesDatabaseHelper.java

@@ -1,17 +1,15 @@
 /*
- * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ * 版权所有 (c) 2010-2011, The MiCode 开源社区 (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
+ * 根据 Apache 许可证 2.0 版本授权
+ * 除非遵守许可证要求，否则不得使用此文件
+ * 您可以在以下网址获取许可证副本：
  *
  *        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.
+ * 除非适用法律要求或书面同意，软件按"原样"分发
+ * 没有任何明示或暗示的担保或条件
+ * 请参阅许可证了解具体权限和限制
  */
 
 package net.micode.notes.data;
@@ -26,64 +24,74 @@ import net.micode.notes.data.Notes.DataColumns;
 import net.micode.notes.data.Notes.DataConstants;
 import net.micode.notes.data.Notes.NoteColumns;
 
-
+/**
+ * 便签应用的数据库帮助类
+ * 负责数据库的创建、升级和管理工作
+ */
 public class NotesDatabaseHelper extends SQLiteOpenHelper {
+    // 数据库名称常量
     private static final String DB_NAME = "note.db";
-
+    // 数据库版本号
     private static final int DB_VERSION = 4;
 
+    /**
+     * 数据库表名定义接口
+     */
     public interface TABLE {
-        public static final String NOTE = "note";
-
-        public static final String DATA = "data";
+        public static final String NOTE = "note";  // 笔记表
+        public static final String DATA = "data";  // 数据表
     }
 
+    // 日志标签
     private static final String TAG = "NotesDatabaseHelper";
-
+    // 单例实例
     private static NotesDatabaseHelper mInstance;
 
+    // 创建笔记表的SQL语句
     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" +
+            NoteColumns.ID + " INTEGER PRIMARY KEY," +               // 笔记ID
+            NoteColumns.PARENT_ID + " INTEGER NOT NULL DEFAULT 0," + // 父文件夹ID
+            NoteColumns.ALERTED_DATE + " INTEGER NOT NULL DEFAULT 0," + // 提醒日期
+            NoteColumns.BG_COLOR_ID + " INTEGER NOT NULL DEFAULT 0," + // 背景颜色ID
+            NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + // 创建日期
+            NoteColumns.HAS_ATTACHMENT + " INTEGER NOT NULL DEFAULT 0," + // 是否有附件
+            NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + // 修改日期
+            NoteColumns.NOTES_COUNT + " INTEGER NOT NULL DEFAULT 0," + // 包含笔记数(文件夹用)
+            NoteColumns.SNIPPET + " TEXT NOT NULL DEFAULT ''," +     // 内容摘要
+            NoteColumns.TYPE + " INTEGER NOT NULL DEFAULT 0," +      // 类型(笔记/文件夹)
+            NoteColumns.WIDGET_ID + " INTEGER NOT NULL DEFAULT 0," +  // 关联的小部件ID
+            NoteColumns.WIDGET_TYPE + " INTEGER NOT NULL DEFAULT -1," + // 小部件类型
+            NoteColumns.SYNC_ID + " INTEGER NOT NULL DEFAULT 0," +    // 同步ID
+            NoteColumns.LOCAL_MODIFIED + " INTEGER NOT NULL DEFAULT 0," + // 本地修改标记
+            NoteColumns.ORIGIN_PARENT_ID + " INTEGER NOT NULL DEFAULT 0," + // 原始父ID
+            NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," +     // Google任务ID
+            NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +    // 版本号
         ")";
 
+    // 创建数据表的SQL语句
     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 ''" +
+            DataColumns.ID + " INTEGER PRIMARY KEY," +               // 数据ID
+            DataColumns.MIME_TYPE + " TEXT NOT NULL," +              // MIME类型
+            DataColumns.NOTE_ID + " INTEGER NOT NULL DEFAULT 0," +   // 关联的笔记ID
+            NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + // 创建日期
+            NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + // 修改日期
+            DataColumns.CONTENT + " TEXT NOT NULL DEFAULT ''," +     // 内容
+            DataColumns.DATA1 + " INTEGER," +                        // 通用数据列1
+            DataColumns.DATA2 + " INTEGER," +                        // 通用数据列2
+            DataColumns.DATA3 + " TEXT NOT NULL DEFAULT ''," +       // 通用数据列3
+            DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," +       // 通用数据列4
+            DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +        // 通用数据列5
         ")";
 
+    // 创建数据表note_id索引的SQL语句
     private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
         "CREATE INDEX IF NOT EXISTS note_id_index ON " +
         TABLE.DATA + "(" + DataColumns.NOTE_ID + ");";
 
     /**
-     * Increase folder's note count when move note to the folder
+     * 触发器：当更新笔记的父文件夹时增加目标文件夹的笔记计数
      */
     private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
         "CREATE TRIGGER increase_folder_count_on_update "+
@@ -95,7 +103,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * Decrease folder's note count when move note from folder
+     * 触发器：当更新笔记的父文件夹时减少原文件夹的笔记计数
      */
     private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
         "CREATE TRIGGER decrease_folder_count_on_update " +
@@ -108,7 +116,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * Increase folder's note count when insert new note to the folder
+     * 触发器：当插入新笔记时增加父文件夹的笔记计数
      */
     private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
         "CREATE TRIGGER increase_folder_count_on_insert " +
@@ -120,7 +128,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * Decrease folder's note count when delete note from the folder
+     * 触发器：当删除笔记时减少父文件夹的笔记计数
      */
     private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =
         "CREATE TRIGGER decrease_folder_count_on_delete " +
@@ -133,7 +141,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * Update note's content when insert data with type {@link DataConstants#NOTE}
+     * 触发器：当插入笔记数据时更新笔记内容摘要
      */
     private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =
         "CREATE TRIGGER update_note_content_on_insert " +
@@ -146,7 +154,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * Update note's content when data with {@link DataConstants#NOTE} type has changed
+     * 触发器：当更新笔记数据时更新笔记内容摘要
      */
     private static final String DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER =
         "CREATE TRIGGER update_note_content_on_update " +
@@ -159,7 +167,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * Update note's content when data with {@link DataConstants#NOTE} type has deleted
+     * 触发器：当删除笔记数据时清空笔记内容摘要
      */
     private static final String DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER =
         "CREATE TRIGGER update_note_content_on_delete " +
@@ -172,7 +180,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * Delete datas belong to note which has been deleted
+     * 触发器：当删除笔记时删除关联的数据
      */
     private static final String NOTE_DELETE_DATA_ON_DELETE_TRIGGER =
         "CREATE TRIGGER delete_data_on_delete " +
@@ -183,7 +191,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * Delete notes belong to folder which has been deleted
+     * 触发器：当删除文件夹时删除其中的所有笔记
      */
     private static final String FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER =
         "CREATE TRIGGER folder_delete_notes_on_delete " +
@@ -194,7 +202,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * Move notes belong to folder which has been moved to trash folder
+     * 触发器：当文件夹被移到回收站时将其中的笔记也移到回收站
      */
     private static final String FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER =
         "CREATE TRIGGER folder_move_notes_on_trash " +
@@ -206,18 +214,31 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
         " END";
 
+    /**
+     * 构造函数
+     * @param context 上下文对象
+     */
     public NotesDatabaseHelper(Context context) {
         super(context, DB_NAME, null, DB_VERSION);
     }
 
+    /**
+     * 创建笔记表
+     * @param db SQLite数据库对象
+     */
     public void createNoteTable(SQLiteDatabase db) {
-        db.execSQL(CREATE_NOTE_TABLE_SQL);
-        reCreateNoteTableTriggers(db);
-        createSystemFolder(db);
+        db.execSQL(CREATE_NOTE_TABLE_SQL);  // 执行建表SQL
+        reCreateNoteTableTriggers(db);      // 重建触发器
+        createSystemFolder(db);             // 创建系统文件夹
         Log.d(TAG, "note table has been created");
     }
 
+    /**
+     * 重建笔记表的所有触发器
+     * @param db SQLite数据库对象
+     */
     private void reCreateNoteTableTriggers(SQLiteDatabase db) {
+        // 删除所有现有触发器
         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");
@@ -226,6 +247,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.execSQL("DROP TRIGGER IF EXISTS folder_delete_notes_on_delete");
         db.execSQL("DROP TRIGGER IF EXISTS folder_move_notes_on_trash");
 
+        // 重新创建所有触发器
         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);
@@ -235,58 +257,69 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER);
     }
 
+    /**
+     * 创建系统文件夹
+     * @param db SQLite数据库对象
+     */
     private void createSystemFolder(SQLiteDatabase db) {
         ContentValues values = new ContentValues();
 
-        /**
-         * call record foler for call notes
-         */
+        // 创建通话记录文件夹
         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
-         */
+        // 创建根文件夹
         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
-         */
+        // 创建临时文件夹
         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
-         */
+        // 创建回收站文件夹
         values.clear();
         values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
         values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
         db.insert(TABLE.NOTE, null, values);
     }
 
+    /**
+     * 创建数据表
+     * @param db SQLite数据库对象
+     */
     public void createDataTable(SQLiteDatabase db) {
-        db.execSQL(CREATE_DATA_TABLE_SQL);
-        reCreateDataTableTriggers(db);
-        db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL);
+        db.execSQL(CREATE_DATA_TABLE_SQL);  // 执行建表SQL
+        reCreateDataTableTriggers(db);      // 重建触发器
+        db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL); // 创建索引
         Log.d(TAG, "data table has been created");
     }
 
+    /**
+     * 重建数据表的所有触发器
+     * @param db SQLite数据库对象
+     */
     private void reCreateDataTableTriggers(SQLiteDatabase db) {
+        // 删除现有触发器
         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");
 
+        // 重新创建触发器
         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);
     }
 
+    /**
+     * 获取单例实例
+     * @param context 上下文对象
+     * @return NotesDatabaseHelper实例
+     */
     static synchronized NotesDatabaseHelper getInstance(Context context) {
         if (mInstance == null) {
             mInstance = new NotesDatabaseHelper(context);
@@ -294,69 +327,100 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         return mInstance;
     }
 
+    /**
+     * 数据库创建时调用
+     * @param db SQLite数据库对象
+     */
     @Override
     public void onCreate(SQLiteDatabase db) {
-        createNoteTable(db);
-        createDataTable(db);
+        createNoteTable(db);  // 创建笔记表
+        createDataTable(db); // 创建数据表
     }
 
+    /**
+     * 数据库升级时调用
+     * @param db SQLite数据库对象
+     * @param oldVersion 旧版本号
+     * @param newVersion 新版本号
+     */
     @Override
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
         boolean reCreateTriggers = false;
         boolean skipV2 = false;
 
+        // 从版本1升级到版本2
         if (oldVersion == 1) {
             upgradeToV2(db);
-            skipV2 = true; // this upgrade including the upgrade from v2 to v3
+            skipV2 = true; // 这个升级包含从v2到v3的升级
             oldVersion++;
         }
 
+        // 从版本2升级到版本3
         if (oldVersion == 2 && !skipV2) {
             upgradeToV3(db);
             reCreateTriggers = true;
             oldVersion++;
         }
 
+        // 从版本3升级到版本4
         if (oldVersion == 3) {
             upgradeToV4(db);
             oldVersion++;
         }
 
+        // 如果需要，重新创建触发器
         if (reCreateTriggers) {
             reCreateNoteTableTriggers(db);
             reCreateDataTableTriggers(db);
         }
 
+        // 检查版本号是否匹配
         if (oldVersion != newVersion) {
-            throw new IllegalStateException("Upgrade notes database to version " + newVersion
-                    + "fails");
+            throw new IllegalStateException("升级笔记数据库到版本 " + newVersion + "失败");
         }
     }
 
+    /**
+     * 升级到版本2
+     * @param db SQLite数据库对象
+     */
     private void upgradeToV2(SQLiteDatabase db) {
+        // 删除旧表
         db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE);
         db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA);
+        // 重新创建表
         createNoteTable(db);
         createDataTable(db);
     }
 
+    /**
+     * 升级到版本3
+     * @param db SQLite数据库对象
+     */
     private void upgradeToV3(SQLiteDatabase db) {
-        // drop unused triggers
+        // 删除不再使用的触发器
         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
+        
+        // 添加Google任务ID列
         db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID
                 + " TEXT NOT NULL DEFAULT ''");
-        // add a trash system folder
+        
+        // 添加回收站系统文件夹
         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);
     }
 
+    /**
+     * 升级到版本4
+     * @param db SQLite数据库对象
+     */
     private void upgradeToV4(SQLiteDatabase db) {
+        // 添加版本号列
         db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
                 + " INTEGER NOT NULL DEFAULT 0");
     }
-}
+}

src/data/NotesProvider.java

@@ -1,22 +1,19 @@
 /*
- * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ * 版权所有 (c) 2010-2011, The MiCode 开源社区 (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
+ * 根据 Apache 许可证 2.0 版本授权
+ * 除非遵守许可证要求，否则不得使用此文件
+ * 您可以在以下网址获取许可证副本：
  *
  *        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.
+ * 除非适用法律要求或书面同意，软件按"原样"分发
+ * 没有任何明示或暗示的担保或条件
+ * 请参阅许可证了解具体权限和限制
  */
 
 package net.micode.notes.data;
 
-
 import android.app.SearchManager;
 import android.content.ContentProvider;
 import android.content.ContentUris;
@@ -34,36 +31,45 @@ import net.micode.notes.data.Notes.DataColumns;
 import net.micode.notes.data.Notes.NoteColumns;
 import net.micode.notes.data.NotesDatabaseHelper.TABLE;
 
-
+/**
+ * 便签应用的内容提供器(ContentProvider)
+ * 负责处理所有数据访问请求，包括增删改查操作
+ */
 public class NotesProvider extends ContentProvider {
+    // URI匹配器，用于识别不同类型的URI请求
     private static final UriMatcher mMatcher;
 
+    // 数据库帮助类实例
     private NotesDatabaseHelper mHelper;
 
+    // 日志标签
     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;
+    // URI匹配类型常量
+    private static final int URI_NOTE            = 1;  // 笔记集合
+    private static final int URI_NOTE_ITEM       = 2;  // 单条笔记
+    private static final int URI_DATA            = 3;  // 数据集合
+    private static final int URI_DATA_ITEM       = 4;  // 单条数据
+    private static final int URI_SEARCH          = 5;  // 搜索
+    private static final int URI_SEARCH_SUGGEST  = 6;  // 搜索建议
 
+    // 静态初始化块，配置URI匹配器
     static {
         mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
-        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);
+        // 添加URI匹配规则
+        mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);                      // 匹配笔记集合
+        mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);              // 匹配单条笔记
+        mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);                     // 匹配数据集合
+        mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM);              // 匹配单条数据
+        mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH);                 // 匹配搜索
+        mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST); // 匹配搜索建议
+        mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST); // 带参数的搜索建议
     }
 
     /**
-     * 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.
+     * 搜索结果的投影(列)定义
+     * x'0A'代表SQLite中的换行符'\n'
+     * 对于搜索结果中的标题和内容，我们会去除换行符和空格以显示更多信息
      */
     private static final String NOTES_SEARCH_PROJECTION = NoteColumns.ID + ","
         + NoteColumns.ID + " AS " + SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA + ","
@@ -73,50 +79,68 @@ public class NotesProvider extends ContentProvider {
         + "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + ","
         + "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA;
 
+    // 笔记片段搜索查询SQL
     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;
+        + " WHERE " + NoteColumns.SNIPPET + " LIKE ?"  // 使用LIKE进行模糊匹配
+        + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER  // 排除回收站中的笔记
+        + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;  // 只搜索普通笔记(非文件夹)
 
+    /**
+     * 内容提供器创建时调用
+     * @return 是否成功创建
+     */
     @Override
     public boolean onCreate() {
+        // 获取数据库帮助类实例
         mHelper = NotesDatabaseHelper.getInstance(getContext());
         return true;
     }
 
+    /**
+     * 查询方法
+     * @param uri 请求的URI
+     * @param projection 要返回的列
+     * @param selection 选择条件
+     * @param selectionArgs 选择参数
+     * @param sortOrder 排序方式
+     * @return 查询结果的Cursor
+     */
     @Override
     public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
             String sortOrder) {
         Cursor c = null;
         SQLiteDatabase db = mHelper.getReadableDatabase();
         String id = null;
+        
+        // 根据URI类型执行不同的查询
         switch (mMatcher.match(uri)) {
-            case URI_NOTE:
+            case URI_NOTE:  // 查询笔记集合
                 c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
                         sortOrder);
                 break;
-            case URI_NOTE_ITEM:
-                id = uri.getPathSegments().get(1);
+            case URI_NOTE_ITEM:  // 查询单条笔记
+                id = uri.getPathSegments().get(1);  // 获取笔记ID
                 c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id
                         + parseSelection(selection), selectionArgs, null, null, sortOrder);
                 break;
-            case URI_DATA:
+            case URI_DATA:  // 查询数据集合
                 c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null,
                         sortOrder);
                 break;
-            case URI_DATA_ITEM:
-                id = uri.getPathSegments().get(1);
+            case URI_DATA_ITEM:  // 查询单条数据
+                id = uri.getPathSegments().get(1);  // 获取数据ID
                 c = db.query(TABLE.DATA, projection, DataColumns.ID + "=" + id
                         + parseSelection(selection), selectionArgs, null, null, sortOrder);
                 break;
-            case URI_SEARCH:
-            case URI_SEARCH_SUGGEST:
+            case URI_SEARCH:  // 搜索请求
+            case URI_SEARCH_SUGGEST:  // 搜索建议请求
                 if (sortOrder != null || projection != null) {
                     throw new IllegalArgumentException(
-                            "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
+                            "搜索查询不支持指定sortOrder、selection、selectionArgs或projection参数");
                 }
 
+                // 获取搜索关键字
                 String searchString = null;
                 if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) {
                     if (uri.getPathSegments().size() > 1) {
@@ -131,72 +155,92 @@ public class NotesProvider extends ContentProvider {
                 }
 
                 try {
+                    // 格式化搜索字符串(添加通配符)
                     searchString = String.format("%%%s%%", searchString);
+                    // 执行原始SQL查询
                     c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY,
                             new String[] { searchString });
                 } catch (IllegalStateException ex) {
-                    Log.e(TAG, "got exception: " + ex.toString());
+                    Log.e(TAG, "查询异常: " + ex.toString());
                 }
                 break;
             default:
-                throw new IllegalArgumentException("Unknown URI " + uri);
+                throw new IllegalArgumentException("未知URI: " + uri);
         }
+        // 设置内容变化通知URI
         if (c != null) {
             c.setNotificationUri(getContext().getContentResolver(), uri);
         }
         return c;
     }
 
+    /**
+     * 插入数据
+     * @param uri 内容URI
+     * @param values 要插入的值
+     * @return 新插入数据的URI
+     */
     @Override
     public Uri insert(Uri uri, ContentValues values) {
         SQLiteDatabase db = mHelper.getWritableDatabase();
         long dataId = 0, noteId = 0, insertedId = 0;
+        
+        // 根据URI类型执行不同的插入操作
         switch (mMatcher.match(uri)) {
-            case URI_NOTE:
+            case URI_NOTE:  // 插入笔记
                 insertedId = noteId = db.insert(TABLE.NOTE, null, values);
                 break;
-            case URI_DATA:
+            case URI_DATA:  // 插入数据
                 if (values.containsKey(DataColumns.NOTE_ID)) {
                     noteId = values.getAsLong(DataColumns.NOTE_ID);
                 } else {
-                    Log.d(TAG, "Wrong data format without note id:" + values.toString());
+                    Log.d(TAG, "数据格式错误，缺少note id:" + values.toString());
                 }
                 insertedId = dataId = db.insert(TABLE.DATA, null, values);
                 break;
             default:
-                throw new IllegalArgumentException("Unknown URI " + uri);
+                throw new IllegalArgumentException("未知URI: " + uri);
         }
-        // Notify the note uri
+        
+        // 通知相关URI的数据变化
         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);
         }
 
+        // 返回新插入数据的URI
         return ContentUris.withAppendedId(uri, insertedId);
     }
 
+    /**
+     * 删除数据
+     * @param uri 内容URI
+     * @param selection 选择条件
+     * @param selectionArgs 选择参数
+     * @return 删除的行数
+     */
     @Override
     public int delete(Uri uri, String selection, String[] selectionArgs) {
         int count = 0;
         String id = null;
         SQLiteDatabase db = mHelper.getWritableDatabase();
         boolean deleteData = false;
+        
+        // 根据URI类型执行不同的删除操作
         switch (mMatcher.match(uri)) {
-            case URI_NOTE:
+            case URI_NOTE:  // 删除笔记集合
                 selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 ";
                 count = db.delete(TABLE.NOTE, selection, selectionArgs);
                 break;
-            case URI_NOTE_ITEM:
+            case URI_NOTE_ITEM:  // 删除单条笔记
                 id = uri.getPathSegments().get(1);
                 /**
-                 * ID that smaller than 0 is system folder which is not allowed to
-                 * trash
+                 * ID小于0的是系统文件夹，不允许删除
                  */
                 long noteId = Long.valueOf(id);
                 if (noteId <= 0) {
@@ -205,19 +249,21 @@ public class NotesProvider extends ContentProvider {
                 count = db.delete(TABLE.NOTE,
                         NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
                 break;
-            case URI_DATA:
+            case URI_DATA:  // 删除数据集合
                 count = db.delete(TABLE.DATA, selection, selectionArgs);
                 deleteData = true;
                 break;
-            case URI_DATA_ITEM:
+            case URI_DATA_ITEM:  // 删除单条数据
                 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);
+                throw new IllegalArgumentException("未知URI: " + uri);
         }
+        
+        // 通知相关URI的数据变化
         if (count > 0) {
             if (deleteData) {
                 getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
@@ -227,37 +273,48 @@ public class NotesProvider extends ContentProvider {
         return count;
     }
 
+    /**
+     * 更新数据
+     * @param uri 内容URI
+     * @param values 新值
+     * @param selection 选择条件
+     * @param selectionArgs 选择参数
+     * @return 更新的行数
+     */
     @Override
     public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
         int count = 0;
         String id = null;
         SQLiteDatabase db = mHelper.getWritableDatabase();
         boolean updateData = false;
+        
+        // 根据URI类型执行不同的更新操作
         switch (mMatcher.match(uri)) {
-            case URI_NOTE:
-                increaseNoteVersion(-1, selection, selectionArgs);
+            case URI_NOTE:  // 更新笔记集合
+                increaseNoteVersion(-1, selection, selectionArgs);  // 增加版本号
                 count = db.update(TABLE.NOTE, values, selection, selectionArgs);
                 break;
-            case URI_NOTE_ITEM:
+            case URI_NOTE_ITEM:  // 更新单条笔记
                 id = uri.getPathSegments().get(1);
-                increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);
+                increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);  // 增加版本号
                 count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id
                         + parseSelection(selection), selectionArgs);
                 break;
-            case URI_DATA:
+            case URI_DATA:  // 更新数据集合
                 count = db.update(TABLE.DATA, values, selection, selectionArgs);
                 updateData = true;
                 break;
-            case URI_DATA_ITEM:
+            case URI_DATA_ITEM:  // 更新单条数据
                 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);
+                throw new IllegalArgumentException("未知URI: " + uri);
         }
 
+        // 通知相关URI的数据变化
         if (count > 0) {
             if (updateData) {
                 getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
@@ -267,17 +324,28 @@ public class NotesProvider extends ContentProvider {
         return count;
     }
 
+    /**
+     * 解析选择条件，添加AND连接
+     * @param selection 原始选择条件
+     * @return 解析后的选择条件
+     */
     private String parseSelection(String selection) {
         return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
     }
 
+    /**
+     * 增加笔记版本号
+     * @param id 笔记ID
+     * @param selection 选择条件
+     * @param selectionArgs 选择参数
+     */
     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 ");
+        sql.append("=" + NoteColumns.VERSION + "+1 ");  // 版本号+1
 
         if (id > 0 || !TextUtils.isEmpty(selection)) {
             sql.append(" WHERE ");
@@ -293,13 +361,18 @@ public class NotesProvider extends ContentProvider {
             sql.append(selectString);
         }
 
+        // 执行SQL语句
         mHelper.getWritableDatabase().execSQL(sql.toString());
     }
 
+    /**
+     * 获取URI对应的MIME类型
+     * @param uri 内容URI
+     * @return MIME类型字符串
+     */
     @Override
     public String getType(Uri uri) {
-        // TODO Auto-generated method stub
+        // TODO 待实现
         return null;
     }
-
-}
+}