添加data包的注释

优化中文语言下的菜单栏显示

MiNote/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java

@@ -299,6 +299,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         Log.d(TAG, "data table has been created");
     }
 
+    // 同上文的execSQL
     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");
@@ -309,6 +310,11 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER);
     }
 
+    /*
+    * 为解决同一时刻只能有一个线程执行
+    * 在写程序库代码时，有时一个类需要杯所有的其他类使用
+    * 但又要求这个类只能被实例化一次，是一个服务类，定义一次，其他类使用此类的同一个实例
+    */
     static synchronized NotesDatabaseHelper getInstance(Context context) {
         if (mInstance == null) {
             mInstance = new NotesDatabaseHelper(context);
@@ -316,12 +322,14 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         return mInstance;
     }
 
+    // 实现上面创建的两个表格
     @Override
     public void onCreate(SQLiteDatabase db) {
         createNoteTable(db);
         createDataTable(db);
     }
 
+    // 数据库版本的更新
     @Override
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
         boolean reCreateTriggers = false;
@@ -355,6 +363,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         }
     }
 
+    // 更新到V2版本
     private void upgradeToV2(SQLiteDatabase db) {
         db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE);
         db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA);
@@ -362,6 +371,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         createDataTable(db);
     }
 
+    // 更新到V3版本
     private void upgradeToV3(SQLiteDatabase db) {
         // drop unused triggers
         db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_insert");
@@ -377,6 +387,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.insert(TABLE.NOTE, null, values);
     }
 
+    // 更新到V4版本
     private void upgradeToV4(SQLiteDatabase db) {
         db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
                 + " INTEGER NOT NULL DEFAULT 0");

MiNote/app/src/main/java/net/micode/notes/data/NotesProvider.java

@@ -25,6 +25,7 @@ import android.content.Intent;
 import android.content.UriMatcher;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
+// Uri代表所要操作的数据，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
 import android.net.Uri;
 import android.text.TextUtils;
 import android.util.Log;
@@ -33,10 +34,18 @@ 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 {
-    private static final UriMatcher mMatcher;
+    private static final UriMatcher mMatcher;// UriMatcher用于匹配Uri
 
     private NotesDatabaseHelper mHelper;
 
@@ -51,7 +60,9 @@ public class NotesProvider extends ContentProvider {
     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);
+        // 把需要匹配的Uri路径全部注册
         mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
         mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);
         mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);
@@ -65,6 +76,7 @@ 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 + ","
@@ -73,25 +85,32 @@ 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 ?"
         + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER
         + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;
 
+    // Context只用在onCreate()中才能被初始化
+    // 对mHelper进行实例化
     @Override
     public boolean onCreate() {
         mHelper = NotesDatabaseHelper.getInstance(getContext());
         return true;
     }
 
+    // 查询Uri在数据库中对应的位置
     @Override
     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 +132,7 @@ 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 +140,8 @@ 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)为第二个元素
                         searchString = uri.getPathSegments().get(1);
                     }
                 } else {
@@ -139,6 +161,7 @@ public class NotesProvider extends ContentProvider {
                 }
                 break;
             default:
+                // 抛出未知uri的异常
                 throw new IllegalArgumentException("Unknown URI " + uri);
         }
         if (c != null) {
@@ -148,14 +171,18 @@ public class NotesProvider extends ContentProvider {
     }
 
     @Override
+    // 插入一个uri
     public Uri insert(Uri uri, ContentValues values) {
+        // 获得一个可写的数据库
         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;
             case URI_DATA:
+                // 如果存在，查找NOTE_ID
                 if (values.containsKey(DataColumns.NOTE_ID)) {
                     noteId = values.getAsLong(DataColumns.NOTE_ID);
                 } else {
@@ -167,6 +194,7 @@ 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);
@@ -178,13 +206,16 @@ public class NotesProvider extends ContentProvider {
                     ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
         }
 
+        // 返回插入的uri路径
         return ContentUris.withAppendedId(uri, insertedId);
     }
 
     @Override
+    // 删除一个uri
     public int delete(Uri uri, String selection, String[] selectionArgs) {
         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 +259,7 @@ 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 +299,12 @@ 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 ");
@@ -293,6 +327,7 @@ 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());
     }
 

MiNote/app/src/main/res/values-zh-rCN/strings.xml

@@ -38,6 +38,9 @@
     <!-- note list string -->
     <string name="menu_secret">私密模式</string>
     <string name="menu_quit_secret">退出私密模式</string>
+    <string name="menu_flower">背景: 花</string>
+    <string name="menu_saying">背景: 山</string>
+    <string name="menu_water">背景: 水</string>
     <string name="menu_create_folder">新建文件夹</string>
     <string name="menu_export_text">导出文本</string>
     <string name="menu_sync">同步</string>