添加data中部分代码的注释

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

@@ -25,10 +25,12 @@ import android.util.Log;
 
 import java.util.HashMap;
 
+// 联系人
 public class Contact {
     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 +38,20 @@ 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 },
@@ -54,17 +59,21 @@ 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 {
                 String name = cursor.getString(0);
                 sContactCache.put(phoneNumber, name);
                 return name;
+                // 异常
             } catch (IndexOutOfBoundsException e) {
                 Log.e(TAG, " Cursor get string error " + e.toString());
                 return null;
             } finally {
                 cursor.close();
             }
+            // 未找到相关信息
         } else {
             Log.d(TAG, "No contact matched with number:" + phoneNumber);
             return null;

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

@@ -20,6 +20,8 @@ import android.net.Uri;
 public class Notes {
     public static final String AUTHORITY = "micode_notes";
     public static final String TAG = "Notes";
+
+    // 以下三个常量在设置NoteColumns.TYPE的时会用到
     public static final int TYPE_NOTE     = 0;
     public static final int TYPE_FOLDER   = 1;
     public static final int TYPE_SYSTEM   = 2;
@@ -54,13 +56,17 @@ public class Notes {
     /**
      * Uri to query all notes and folders
      */
-    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
+    // 定义查询便签和文件夹的指针
+    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");//
 
     /**
      * Uri to query data
      */
+    // 定义查找数据的指针
     public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
 
+    // 定义NoteColumns的常量，用于后面创建数据库的表头
+    // 这些常量主要用于定义便签的属性
     public interface NoteColumns {
         /**
          * The unique ID for a row
@@ -167,6 +173,8 @@ public class Notes {
         public static final String VERSION = "version";
     }
 
+    // 定义DataColumns的常量，用于后面创建数据库的表头
+    // 主要用于定义储存便签内容数据
     public interface DataColumns {
         /**
          * The unique ID for a row
@@ -241,6 +249,7 @@ public class Notes {
         public static final String DATA5 = "data5";
     }
 
+    // 文本内容的数据结构
     public static final class TextNote implements DataColumns {
         /**
          * Mode to indicate the text in check list mode or not
@@ -257,6 +266,7 @@ public class Notes {
         public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");
     }
 
+    // 电话内容的数据结构
     public static final class CallNote implements DataColumns {
         /**
          * Call date for this record

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

@@ -16,22 +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;// 用于保存数据信息，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
+import android.database.sqlite.SQLiteDatabase;// 主要提供了用于添加、删除、更新、查询的操作方法：insert(), delete(), update()和query()。配合content.values使用
+import android.database.sqlite.SQLiteOpenHelper;// 用于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，用于SQLOpenHelper，对一些note和文件进行数据库的操作，比如删除文件时删除对应的note
 public class NotesDatabaseHelper extends SQLiteOpenHelper {
     private static final String DB_NAME = "note.db";
 
     private static final int DB_VERSION = 4;
 
+    // 接口，分为note和data
     public interface TABLE {
         public static final String NOTE = "note";
 
@@ -42,6 +43,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 
     private static NotesDatabaseHelper mInstance;
 
+    // 数据库中需要存储的项目的名称，创建表头内容
     private static final String CREATE_NOTE_TABLE_SQL =
         "CREATE TABLE " + TABLE.NOTE + "(" +
             NoteColumns.ID + " INTEGER PRIMARY KEY," +
@@ -63,6 +65,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
         ")";
 
+    // 同上，存储项目不同
     private static final String CREATE_DATA_TABLE_SQL =
         "CREATE TABLE " + TABLE.DATA + "(" +
             DataColumns.ID + " INTEGER PRIMARY KEY," +
@@ -78,6 +81,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +
         ")";
 
+    // 存储便签编号的数据表格
     private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
         "CREATE INDEX IF NOT EXISTS note_id_index ON " +
         TABLE.DATA + "(" + DataColumns.NOTE_ID + ");";
@@ -85,6 +89,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Increase folder's note count when move note to the folder
      */
+    // 在文件夹中移入一个Note之后需要更改的数据表格
     private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
         "CREATE TRIGGER increase_folder_count_on_update "+
         " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
@@ -97,6 +102,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Decrease folder's note count when move note from folder
      */
+    // 在文件夹中移出一个Note之后需要更改的数据表格
     private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
         "CREATE TRIGGER decrease_folder_count_on_update " +
         " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
@@ -110,6 +116,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Increase folder's note count when insert new note to the folder
      */
+    // 在文件夹中插入一个Note之后需要更改的数据表格
     private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
         "CREATE TRIGGER increase_folder_count_on_insert " +
         " AFTER INSERT ON " + TABLE.NOTE +
@@ -122,6 +129,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Decrease folder's note count when delete note from the folder
      */
+    // 在文件夹中删除一个Note之后需要更改的数据表格
     private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =
         "CREATE TRIGGER decrease_folder_count_on_delete " +
         " AFTER DELETE ON " + TABLE.NOTE +
@@ -135,6 +143,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Update note's content when insert data with type {@link DataConstants#NOTE}
      */
+    // 在文件夹中对于一个Note导入新的数据之后需要更改的数据表格
     private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =
         "CREATE TRIGGER update_note_content_on_insert " +
         " AFTER INSERT ON " + TABLE.DATA +
@@ -148,6 +157,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Update note's content when data with {@link DataConstants#NOTE} type has changed
      */
+    // Note数据被更改后需要修改的数据表格
     private static final String DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER =
         "CREATE TRIGGER update_note_content_on_update " +
         " AFTER UPDATE ON " + TABLE.DATA +
@@ -161,6 +171,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Update note's content when data with {@link DataConstants#NOTE} type has deleted
      */
+    // Note数据被删除后需要修改的数据表格
     private static final String DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER =
         "CREATE TRIGGER update_note_content_on_delete " +
         " AFTER delete ON " + TABLE.DATA +
@@ -174,6 +185,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Delete datas belong to note which has been deleted
      */
+    // 删除已删除的Note数据后需要修改的数据表格
     private static final String NOTE_DELETE_DATA_ON_DELETE_TRIGGER =
         "CREATE TRIGGER delete_data_on_delete " +
         " AFTER DELETE ON " + TABLE.NOTE +
@@ -185,6 +197,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Delete notes belong to folder which has been deleted
      */
+    // 删除已删除的文件夹的Note后需要修改的数据表格
     private static final String FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER =
         "CREATE TRIGGER folder_delete_notes_on_delete " +
         " AFTER DELETE ON " + TABLE.NOTE +
@@ -196,6 +209,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Move notes belong to folder which has been moved to trash folder
      */
+    // 还原垃圾桶中Note后需要更改的数据表格
     private static final String FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER =
         "CREATE TRIGGER folder_move_notes_on_trash " +
         " AFTER UPDATE ON " + TABLE.NOTE +
@@ -206,10 +220,12 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         "  WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
         " END";
 
+    // 构造函数，传入数据库的名称和版本
     public NotesDatabaseHelper(Context context) {
         super(context, DB_NAME, null, DB_VERSION);
     }
 
+    // 创建表格（用于存储标签属性）
     public void createNoteTable(SQLiteDatabase db) {
         db.execSQL(CREATE_NOTE_TABLE_SQL);
         reCreateNoteTableTriggers(db);
@@ -217,6 +233,10 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         Log.d(TAG, "note table has been created");
     }
 
+    /*
+    execSQL是数据库操作的API，主要是更改行为的SQL语句
+    在这里主要是用于重新创建上述定义表格，先删除原有的数据库的触发器再重新创建新的数据库
+    */
     private void reCreateNoteTableTriggers(SQLiteDatabase db) {
         db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_update");
         db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_update");
@@ -235,6 +255,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER);
     }
 
+    // 创建系统文件夹
     private void createSystemFolder(SQLiteDatabase db) {
         ContentValues values = new ContentValues();
 
@@ -270,6 +291,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.insert(TABLE.NOTE, null, values);
     }
 
+    // 创建表格（用于存储标签内容）
     public void createDataTable(SQLiteDatabase db) {
         db.execSQL(CREATE_DATA_TABLE_SQL);
         reCreateDataTableTriggers(db);