2024/12/21 data包、tool包 代码注释

src/net/micode/notes/data/Contact.java

@@ -25,10 +25,11 @@ import android.util.Log;
 
 import java.util.HashMap;
 
-public class Contact {
+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 "
@@ -36,17 +37,20 @@ public class Contact {
             + " 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中是否已有phoneNumber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的信息
         Cursor cursor = context.getContentResolver().query(
                 Data.CONTENT_URI,
                 new String [] { Phone.DISPLAY_NAME },
@@ -54,16 +58,21 @@ public class Contact {
                 new String[] { phoneNumber },
                 null);
 
+        // 判定查询结果
+        // moveToFirst()返回第一条
         if (cursor != null && cursor.moveToFirst()) {
             try {
+                // 找到相关信息
                 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);

src/net/micode/notes/data/Notes.java

@@ -17,9 +17,11 @@
 package net.micode.notes.data;
 
 import android.net.Uri;
+// Notes 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";
+    //以下三个常量对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;
@@ -54,13 +56,14 @@ public class Notes {
     /**
      * Uri to query all notes and folders
      */
-    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
+    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");
+    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
@@ -72,7 +75,7 @@ public class Notes {
          * The parent's id for note or folder
          * <P> Type: INTEGER (long) </P>
          */
-        public static final String PARENT_ID = "parent_id";
+        public static final String PARENT_ID = "parent_id";//为什么会有parent_id
 
         /**
          * Created data for note or folder
@@ -140,7 +143,7 @@ public class Notes {
          * The last sync id
          * <P> Type: INTEGER (long) </P>
          */
-        public static final String SYNC_ID = "sync_id";
+        public static final String SYNC_ID = "sync_id";//同步
 
         /**
          * Sign to indicate local modified or not
@@ -165,8 +168,9 @@ public class Notes {
          * <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
@@ -239,7 +243,7 @@ public class Notes {
          * <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 {
         /**
@@ -255,7 +259,7 @@ public class Notes {
         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 {
         /**
@@ -275,5 +279,5 @@ public class Notes {
         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
 }

src/net/micode/notes/data/NotesDatabaseHelper.java

@@ -16,23 +16,23 @@
 
 package net.micode.notes.data;
 
-import android.content.ContentValues;
-import android.content.Context;
-import android.database.sqlite.SQLiteDatabase;
-import android.database.sqlite.SQLiteOpenHelper;
+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 {
+    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";
@@ -61,7 +61,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             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 + "(" +
@@ -76,11 +76,11 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             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 + ");";
+        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
@@ -92,7 +92,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  UPDATE " + TABLE.NOTE +
         "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
         "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
-        " END";
+        " 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
@@ -105,7 +105,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
         "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
         "  AND " + NoteColumns.NOTES_COUNT + ">0" + ";" +
-        " END";
+        " END";//在文件夹中插入一个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
@@ -117,7 +117,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  UPDATE " + TABLE.NOTE +
         "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
         "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
-        " END";
+        " END";//在文件夹中删除一个Note之后需要更改的数据的表格。
 
     /**
      * Decrease folder's note count when delete note from the folder
@@ -130,7 +130,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
         "  WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
         "  AND " + NoteColumns.NOTES_COUNT + ">0;" +
-        " END";
+        " 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}
@@ -143,7 +143,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  UPDATE " + TABLE.NOTE +
         "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
         "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
-        " END";
+        " 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
@@ -156,7 +156,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  UPDATE " + TABLE.NOTE +
         "   SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
         "  WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
-        " END";
+        " 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
@@ -169,7 +169,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  UPDATE " + TABLE.NOTE +
         "   SET " + NoteColumns.SNIPPET + "=''" +
         "  WHERE " + NoteColumns.ID + "=old." + DataColumns.NOTE_ID + ";" +
-        " END";
+        " 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
@@ -180,7 +180,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " BEGIN" +
         "  DELETE FROM " + TABLE.DATA +
         "   WHERE " + DataColumns.NOTE_ID + "=old." + NoteColumns.ID + ";" +
-        " END";
+        " 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
@@ -191,7 +191,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " BEGIN" +
         "  DELETE FROM " + TABLE.NOTE +
         "   WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
-        " END";
+        " 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
@@ -204,18 +204,18 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  UPDATE " + TABLE.NOTE +
         "   SET " + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
         "  WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
-        " END";
+        " 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");
@@ -233,7 +233,8 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         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();
@@ -268,14 +269,14 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         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");
@@ -285,20 +286,22 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         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) {
@@ -331,14 +334,14 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             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
@@ -353,10 +356,10 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         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
 }

src/net/micode/notes/data/NotesProvider.java

@@ -34,7 +34,13 @@ 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 {
     private static final UriMatcher mMatcher;
 
@@ -50,8 +56,9 @@ public class NotesProvider extends ContentProvider {
     private static final int URI_SEARCH          = 5;
     private static final int URI_SEARCH_SUGGEST  = 6;
 
-    static {
+    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);
@@ -65,6 +72,7 @@ public class NotesProvider extends ContentProvider {
      * 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 + ","
@@ -73,6 +81,7 @@ public class NotesProvider extends ContentProvider {
         + "'" + 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 ?"
@@ -80,18 +89,24 @@ public class NotesProvider extends ContentProvider {
         + " 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);
@@ -113,6 +128,7 @@ public class NotesProvider extends ContentProvider {
             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");
                 }
@@ -120,6 +136,8 @@ public class NotesProvider extends ContentProvider {
                 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 {
@@ -139,6 +157,7 @@ public class NotesProvider extends ContentProvider {
                 }
                 break;
             default:
+                // 抛出异常
                 throw new IllegalArgumentException("Unknown URI " + uri);
         }
         if (c != null) {
@@ -148,13 +167,17 @@ public class NotesProvider extends ContentProvider {
     }
 
     @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);
@@ -167,6 +190,7 @@ public class NotesProvider extends ContentProvider {
                 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);
@@ -177,14 +201,17 @@ public class NotesProvider extends ContentProvider {
             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)) {
@@ -228,6 +255,7 @@ public class NotesProvider extends ContentProvider {
     }
 
     @Override
+    // 更新一个uri
     public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
         int count = 0;
         String id = null;
@@ -267,10 +295,11 @@ public class NotesProvider extends ContentProvider {
         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 ");
@@ -292,7 +321,7 @@ public class NotesProvider extends ContentProvider {
             }
             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());
     }
 

src/net/micode/notes/tool/BackupUtils.java

@@ -37,12 +37,16 @@ import java.io.PrintStream;
 
 
 public class BackupUtils {
-    private static final String TAG = "BackupUtils";
+    private static final String TAG = "BackupUtils"; //类里面为什么可以定义自身类的对象？
     // Singleton stuff
     private static BackupUtils sInstance;
 
     public static synchronized BackupUtils getInstance(Context context) {
+        //ynchronized 关键字，代表这个方法加锁,相当于不管哪一个线程（例如线程A）
+        //运行到这个方法时,都要检查有没有其它线程B（或者C、 D等）正在用这个方法(或者该类的其他同步方法)，有的话要等正在使用synchronized方法的线程B（或者C 、D）运行完这个方法后再运行此线程A,没有的话,锁定调用者,然后直接运行。
+        //它包括两种用法：synchronized 方法和 synchronized 块。
         if (sInstance == null) {
+            //如果当前备份不存在，则新声明一个
             sInstance = new BackupUtils(context);
         }
         return sInstance;
@@ -52,24 +56,26 @@ public class BackupUtils {
      * Following states are signs to represents backup or restore
      * status
      */
-    // Currently, the sdcard is not mounted
+    // Currently, the sdcard is not mounted SD  卡没有被装入手机
     public static final int STATE_SD_CARD_UNMOUONTED           = 0;
-    // The backup file not exist
+    // The backup file not exist  备份文件夹不存在
     public static final int STATE_BACKUP_FILE_NOT_EXIST        = 1;
-    // The data is not well formated, may be changed by other programs
+    // The data is not well formated, may be changed by other programs 数据已被破坏，可能被修改
     public static final int STATE_DATA_DESTROIED               = 2;
-    // Some run-time exception which causes restore or backup fails
+    // Some run-time exception which causes restore or backup fails  超时异常
     public static final int STATE_SYSTEM_ERROR                 = 3;
-    // Backup or restore success
+    // Backup or restore success  成功存储
     public static final int STATE_SUCCESS                      = 4;
 
     private TextExport mTextExport;
 
+    //初始化函数
     private BackupUtils(Context context) {
         mTextExport = new TextExport(context);
     }
 
     private static boolean externalStorageAvailable() {
+        //外部存储功能是否可用
         return Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState());
     }
 
@@ -128,10 +134,11 @@ public class BackupUtils {
         public TextExport(Context context) {
             TEXT_FORMAT = context.getResources().getStringArray(R.array.format_for_exported_note);
             mContext = context;
-            mFileName = "";
+            mFileName = "";  //为什么为空?
             mFileDirectory = "";
         }
 
+        //获取文本的组成部分
         private String getFormat(int id) {
             return TEXT_FORMAT[id];
         }
@@ -140,7 +147,7 @@ public class BackupUtils {
          * Export the folder identified by folder id to text
          */
         private void exportFolderToText(String folderId, PrintStream ps) {
-            // Query notes belong to this folder
+            // Query notes belong to this folder  通过查询parent id是文件夹id的note来选出制定ID文件夹下的Note
             Cursor notesCursor = mContext.getContentResolver().query(Notes.CONTENT_NOTE_URI,
                     NOTE_PROJECTION, NoteColumns.PARENT_ID + "=?", new String[] {
                         folderId
@@ -149,13 +156,13 @@ public class BackupUtils {
             if (notesCursor != null) {
                 if (notesCursor.moveToFirst()) {
                     do {
-                        // Print note's last modified date
+                        // Print note's last modified date   ps里面保存有这份note的日期
                         ps.println(String.format(getFormat(FORMAT_NOTE_DATE), DateFormat.format(
                                 mContext.getString(R.string.format_datetime_mdhm),
                                 notesCursor.getLong(NOTE_COLUMN_MODIFIED_DATE))));
                         // Query data belong to this note
                         String noteId = notesCursor.getString(NOTE_COLUMN_ID);
-                        exportNoteToText(noteId, ps);
+                        exportNoteToText(noteId, ps); //将文件导出到text
                     } while (notesCursor.moveToNext());
                 }
                 notesCursor.close();
@@ -172,6 +179,7 @@ public class BackupUtils {
                     }, null);
 
             if (dataCursor != null) {
+                //利用光标来扫描内容，区别为callnote和note两种，靠ps.printline输出
                 if (dataCursor.moveToFirst()) {
                     do {
                         String mimeType = dataCursor.getString(DATA_COLUMN_MIME_TYPE);
@@ -181,7 +189,7 @@ public class BackupUtils {
                             long callDate = dataCursor.getLong(DATA_COLUMN_CALL_DATE);
                             String location = dataCursor.getString(DATA_COLUMN_CONTENT);
 
-                            if (!TextUtils.isEmpty(phoneNumber)) {
+                            if (!TextUtils.isEmpty(phoneNumber)) {  //判断是否为空字符
                                 ps.println(String.format(getFormat(FORMAT_NOTE_CONTENT),
                                         phoneNumber));
                             }
@@ -218,7 +226,7 @@ public class BackupUtils {
         /**
          * Note will be exported as text which is user readable
          */
-        public int exportToText() {
+        public int exportToText() {  //总函数，调用上面的exportFolder和exportNote
             if (!externalStorageAvailable()) {
                 Log.d(TAG, "Media was not mounted");
                 return STATE_SD_CARD_UNMOUONTED;
@@ -229,7 +237,7 @@ public class BackupUtils {
                 Log.e(TAG, "get print stream error");
                 return STATE_SYSTEM_ERROR;
             }
-            // First export folder and its notes
+            // First export folder and its notes                                 导出文件夹，就是导出里面包含的便签
             Cursor folderCursor = mContext.getContentResolver().query(
                     Notes.CONTENT_NOTE_URI,
                     NOTE_PROJECTION,
@@ -257,7 +265,7 @@ public class BackupUtils {
                 folderCursor.close();
             }
 
-            // Export notes in root's folder
+            // Export notes in root's folder        将根目录里的便签导出（由于不属于任何文件夹，因此无法通过文件夹导出来实现这一部分便签的导出）
             Cursor noteCursor = mContext.getContentResolver().query(
                     Notes.CONTENT_NOTE_URI,
                     NOTE_PROJECTION,
@@ -297,7 +305,7 @@ public class BackupUtils {
             PrintStream ps = null;
             try {
                 FileOutputStream fos = new FileOutputStream(file);
-                ps = new PrintStream(fos);
+                ps = new PrintStream(fos);   //将ps输出流输出到特定的文件，目的就是导出到文件，而不是直接输出
             } catch (FileNotFoundException e) {
                 e.printStackTrace();
                 return null;
@@ -314,16 +322,16 @@ public class BackupUtils {
      */
     private static File generateFileMountedOnSDcard(Context context, int filePathResId, int fileNameFormatResId) {
         StringBuilder sb = new StringBuilder();
-        sb.append(Environment.getExternalStorageDirectory());
-        sb.append(context.getString(filePathResId));
-        File filedir = new File(sb.toString());
+        sb.append(Environment.getExternalStorageDirectory());   //外部（SD卡）的存储路径
+        sb.append(context.getString(filePathResId));     //文件的存储路径
+        File filedir = new File(sb.toString());     //filedir应该就是用来存储路径信息
         sb.append(context.getString(
                 fileNameFormatResId,
                 DateFormat.format(context.getString(R.string.format_date_ymd),
                         System.currentTimeMillis())));
         File file = new File(sb.toString());
 
-        try {
+        try {   //如果这些文件不存在，则新建
             if (!filedir.exists()) {
                 filedir.mkdir();
             }
@@ -336,7 +344,7 @@ public class BackupUtils {
         } catch (IOException e) {
             e.printStackTrace();
         }
-
+        // try catch 异常处理
         return null;
     }
 }

src/net/micode/notes/tool/DataUtils.java

@@ -38,6 +38,7 @@ import java.util.HashSet;
 public class DataUtils {
     public static final String TAG = "DataUtils";
     public static boolean batchDeleteNotes(ContentResolver resolver, HashSet<Long> ids) {
+        //直接删除多个笔记
         if (ids == null) {
             Log.d(TAG, "the ids is null");
             return true;
@@ -47,18 +48,19 @@ public class DataUtils {
             return true;
         }
 
-        ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
+        ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();  //提供一个任务列表
         for (long id : ids) {
             if(id == Notes.ID_ROOT_FOLDER) {
                 Log.e(TAG, "Don't delete system folder root");
                 continue;
-            }
+            }   //如果发现是根文件夹，则不删除
             ContentProviderOperation.Builder builder = ContentProviderOperation
-                    .newDelete(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id));
+                    .newDelete(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id));     //用newDelete实现删除功能
             operationList.add(builder.build());
         }
         try {
-            ContentProviderResult[] results = resolver.applyBatch(Notes.AUTHORITY, operationList);
+            ContentProviderResult[] results = resolver.applyBatch(Notes.AUTHORITY, operationList);  //主机名（或叫Authority）用于唯一标识这个ContentProvider，外部调用者可以根据这个标识来找到它。
+            //数据库事务，数据库事务是由一组数据库操作序列组成，事务作为一个整体被执行
             if (results == null || results.length == 0 || results[0] == null) {
                 Log.d(TAG, "delete notes failed, ids:" + ids.toString());
                 return false;
@@ -77,7 +79,7 @@ public class DataUtils {
         values.put(NoteColumns.PARENT_ID, desFolderId);
         values.put(NoteColumns.ORIGIN_PARENT_ID, srcFolderId);
         values.put(NoteColumns.LOCAL_MODIFIED, 1);
-        resolver.update(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id), values, null, null);
+        resolver.update(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id), values, null, null);    //对需要移动的便签进行数据更新，然后用update实现
     }
 
     public static boolean batchMoveToFolder(ContentResolver resolver, HashSet<Long> ids,
@@ -90,14 +92,14 @@ public class DataUtils {
         ArrayList<ContentProviderOperation> operationList = new ArrayList<ContentProviderOperation>();
         for (long id : ids) {
             ContentProviderOperation.Builder builder = ContentProviderOperation
-                    .newUpdate(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id));
+                    .newUpdate(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, id));     //通过withAppendedId方法，为该Uri加上ID
             builder.withValue(NoteColumns.PARENT_ID, folderId);
             builder.withValue(NoteColumns.LOCAL_MODIFIED, 1);
             operationList.add(builder.build());
-        }
+        }   //将ids里包含的每一列的数据逐次加入到operationList中，等待最后的批量处理
 
         try {
-            ContentProviderResult[] results = resolver.applyBatch(Notes.AUTHORITY, operationList);
+            ContentProviderResult[] results = resolver.applyBatch(Notes.AUTHORITY, operationList)   //applyBatch一次性处理一个操作列表
             if (results == null || results.length == 0 || results[0] == null) {
                 Log.d(TAG, "delete notes failed, ids:" + ids.toString());
                 return false;
@@ -119,7 +121,7 @@ public class DataUtils {
                 new String[] { "COUNT(*)" },
                 NoteColumns.TYPE + "=? AND " + NoteColumns.PARENT_ID + "<>?",
                 new String[] { String.valueOf(Notes.TYPE_FOLDER), String.valueOf(Notes.ID_TRASH_FOLER)},
-                null);
+                null);   //筛选条件：源文件不为trash folder
 
         int count = 0;
         if(cursor != null) {
@@ -137,15 +139,15 @@ public class DataUtils {
     }
 
     public static boolean visibleInNoteDatabase(ContentResolver resolver, long noteId, int type) {
-        Cursor cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId),
+        Cursor cursor = resolver.query(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId),  //通过withAppendedId方法，为该Uri加上ID
                 null,
                 NoteColumns.TYPE + "=? AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER,
                 new String [] {String.valueOf(type)},
-                null);
+                null);      //查询条件：type符合，且不属于垃圾文件夹
 
         boolean exist = false;
         if (cursor != null) {
-            if (cursor.getCount() > 0) {
+            if (cursor.getCount() > 0) {    //用getcount函数判断cursor是否为空
                 exist = true;
             }
             cursor.close();
@@ -187,6 +189,7 @@ public class DataUtils {
                 " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER +
                 " AND " + NoteColumns.SNIPPET + "=?",
                 new String[] { name }, null);
+        //通过名字查询文件是否存在
         boolean exist = false;
         if(cursor != null) {
             if(cursor.getCount() > 0) {
@@ -202,7 +205,7 @@ public class DataUtils {
                 new String[] { NoteColumns.WIDGET_ID, NoteColumns.WIDGET_TYPE },
                 NoteColumns.PARENT_ID + "=?",
                 new String[] { String.valueOf(folderId) },
-                null);
+                null);  //查询条件：父ID是传入的folderId;
 
         HashSet<AppWidgetAttribute> set = null;
         if (c != null) {
@@ -217,7 +220,7 @@ public class DataUtils {
                     } catch (IndexOutOfBoundsException e) {
                         Log.e(TAG, e.toString());
                     }
-                } while (c.moveToNext());
+                } while (c.moveToNext());   //查询下一条
             }
             c.close();
         }
@@ -250,7 +253,7 @@ public class DataUtils {
                 + CallNote.PHONE_NUMBER + ",?)",
                 new String [] { String.valueOf(callDate), CallNote.CONTENT_ITEM_TYPE, phoneNumber },
                 null);
-
+        //通过数据库操作，查询条件是（callDate和phoneNumber匹配传入参数的值）
         if (cursor != null) {
             if (cursor.moveToFirst()) {
                 try {
@@ -269,7 +272,7 @@ public class DataUtils {
                 new String [] { NoteColumns.SNIPPET },
                 NoteColumns.ID + "=?",
                 new String [] { String.valueOf(noteId)},
-                null);
+                null);      //查询条件：noteId
 
         if (cursor != null) {
             String snippet = "";
@@ -282,7 +285,8 @@ public class DataUtils {
         throw new IllegalArgumentException("Note is not found with id: " + noteId);
     }
 
-    public static String getFormattedSnippet(String snippet) {
+    public static String getFormattedSnippet(String snippet){
+        //对字符串进行格式处理，将字符串两头的空格去掉，同时将换行符去掉
         if (snippet != null) {
             snippet = snippet.trim();
             int index = snippet.indexOf('\n');

src/net/micode/notes/tool/GTaskStringUtils.java

@@ -13,9 +13,17 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/*
+  简介：定义了很多的静态字符串，目的就是为了提供jsonObject中相应字符串的"key"。
+       把这些静态的定义单独写到了一个类里面，这是非常好的编程规范
+*/
 
 package net.micode.notes.tool;
 
+/*
+    这个类就是定义了一堆static string，实际就是为jsonObject提供Key，
+    把这些定义全部写到一个类里，方便查看管理，是一个非常好的编程习惯
+*/
 public class GTaskStringUtils {
 
     public final static String GTASK_JSON_ACTION_ID = "action_id";

src/net/micode/notes/tool/ResourceParser.java

@@ -15,7 +15,20 @@
  */
 
 package net.micode.notes.tool;
-
+/*简介：字面意义是资源分析器，实际上就是获取资源并且在程序中使用，比如颜色图片等
+ * 实现方法：主要利用R.java这个类，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）
+ * BG_DEFAULT_FONT_SIZE 默认文本大小（中）
+ */
 import android.content.Context;
 import android.preference.PreferenceManager;
 
@@ -65,6 +78,7 @@ public class ResourceParser {
         }
     }
 
+    //直接获取默认的背景颜色。看不太懂，这个PREFERENCE_SET_BG_COLOR_KEY是个final string,也就是说getBoolean肯定执行else，为什么要这么写
     public static int getDefaultBgId(Context context) {
         if (PreferenceManager.getDefaultSharedPreferences(context).getBoolean(
                 NotesPreferenceActivity.PREFERENCE_SET_BG_COLOR_KEY, false)) {
@@ -162,6 +176,7 @@ public class ResourceParser {
             R.style.TextAppearanceSuper
         };
 
+        //这里有一个容错的函数，防止输入的id大于资源总量，若如此，则自动返回默认的设置结果
         public static int getTexAppearanceResource(int id) {
             /**
              * HACKME: Fix bug of store the resource id in shared preference.