diff --git a/src/.idea/workspace.xml b/src/.idea/workspace.xml
index 0f59503..4ff6873 100644
--- a/src/.idea/workspace.xml
+++ b/src/.idea/workspace.xml
@@ -6,10 +6,7 @@
     </shared>
   </component>
   <component name="ChangeListManager">
-    <list default="true" id="c8515555-ebbc-49d5-889b-0c59bd6c3b6d" name="默认更改列表" comment="ziji wu comment">
-      <change beforePath="$PROJECT_DIR$/.gradle/5.4.1/executionHistory/executionHistory.lock" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/5.4.1/executionHistory/executionHistory.lock" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gradle/5.4.1/fileHashes/fileHashes.lock" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/5.4.1/fileHashes/fileHashes.lock" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.gradle/buildOutputCleanup/buildOutputCleanup.lock" beforeDir="false" afterPath="$PROJECT_DIR$/.gradle/buildOutputCleanup/buildOutputCleanup.lock" afterDir="false" />
+    <list default="true" id="c8515555-ebbc-49d5-889b-0c59bd6c3b6d" name="默认更改列表" comment="">
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/Notes.java" beforeDir="false" afterPath="$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/Notes.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java" beforeDir="false" afterPath="$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java" afterDir="false" />
@@ -36,7 +33,7 @@
       <file pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/Contact.java">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="620">
+            <state relative-caret-position="440">
               <caret line="52" column="17" selection-start-line="52" selection-start-column="17" selection-end-line="52" selection-end-column="17" />
               <folding>
                 <element signature="imports" expanded="true" />
@@ -45,11 +42,11 @@
           </provider>
         </entry>
       </file>
-      <file pinned="false" current-in-tab="true">
+      <file pinned="false" current-in-tab="false">
         <entry file="file://$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/Notes.java">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="216">
-              <caret line="68" column="39" selection-start-line="68" selection-start-column="39" selection-end-line="68" selection-end-column="39" />
+            <state relative-caret-position="164">
+              <caret line="177" column="40" selection-start-line="177" selection-start-column="40" selection-end-line="177" selection-end-column="40" />
             </state>
           </provider>
         </entry>
@@ -75,11 +72,15 @@
           </provider>
         </entry>
       </file>
-      <file pinned="false" current-in-tab="false">
+      <file pinned="false" current-in-tab="true">
         <entry file="file://$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="355">
-              <caret line="49" column="36" lean-forward="true" selection-start-line="49" selection-start-column="36" selection-end-line="49" selection-end-column="36" />
+            <state relative-caret-position="244">
+              <caret line="316" column="8" lean-forward="true" selection-start-line="316" selection-start-column="8" selection-end-line="316" selection-end-column="8" />
+              <folding>
+                <element signature="e#9077#9078#0" expanded="true" />
+                <element signature="e#9134#9135#0" expanded="true" />
+              </folding>
             </state>
           </provider>
         </entry>
@@ -129,14 +130,14 @@
         <option value="$PROJECT_DIR$/app/src/main/java/net/micode/notes/tool/BackupUtils.java" />
         <option value="$PROJECT_DIR$/app/src/main/res/xml/widget_4x_info.xml" />
         <option value="$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/Contact.java" />
-        <option value="$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java" />
         <option value="$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/Notes.java" />
+        <option value="$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java" />
       </list>
     </option>
   </component>
   <component name="ProjectFrameBounds" extendedState="6">
-    <option name="x" value="-9" />
-    <option name="y" value="-9" />
+    <option name="x" value="85" />
+    <option name="y" value="25" />
     <option name="width" value="1750" />
     <option name="height" value="1030" />
   </component>
@@ -174,6 +175,37 @@
               <item name="notes" type="cbb59c9e:AndroidPsiDirectoryNode" />
               <item name="data" type="462c0819:PsiDirectoryNode" />
             </path>
+            <path>
+              <item name="src" type="1abcf292:AndroidViewProjectNode" />
+              <item name="app" type="feadf853:AndroidModuleNode" />
+              <item name="java" type="edd41e36:AndroidSourceTypeNode" />
+              <item name="notes" type="cbb59c9e:AndroidPsiDirectoryNode" />
+              <item name="gtask" type="462c0819:PsiDirectoryNode" />
+            </path>
+            <path>
+              <item name="src" type="1abcf292:AndroidViewProjectNode" />
+              <item name="app" type="feadf853:AndroidModuleNode" />
+              <item name="java" type="edd41e36:AndroidSourceTypeNode" />
+              <item name="notes" type="cbb59c9e:AndroidPsiDirectoryNode" />
+              <item name="gtask" type="462c0819:PsiDirectoryNode" />
+              <item name="data" type="462c0819:PsiDirectoryNode" />
+            </path>
+            <path>
+              <item name="src" type="1abcf292:AndroidViewProjectNode" />
+              <item name="app" type="feadf853:AndroidModuleNode" />
+              <item name="java" type="edd41e36:AndroidSourceTypeNode" />
+              <item name="notes" type="cbb59c9e:AndroidPsiDirectoryNode" />
+              <item name="gtask" type="462c0819:PsiDirectoryNode" />
+              <item name="exception" type="462c0819:PsiDirectoryNode" />
+            </path>
+            <path>
+              <item name="src" type="1abcf292:AndroidViewProjectNode" />
+              <item name="app" type="feadf853:AndroidModuleNode" />
+              <item name="java" type="edd41e36:AndroidSourceTypeNode" />
+              <item name="notes" type="cbb59c9e:AndroidPsiDirectoryNode" />
+              <item name="gtask" type="462c0819:PsiDirectoryNode" />
+              <item name="remote" type="462c0819:PsiDirectoryNode" />
+            </path>
             <path>
               <item name="src" type="1abcf292:AndroidViewProjectNode" />
               <item name="app" type="feadf853:AndroidModuleNode" />
@@ -206,6 +238,12 @@
               <item name="res" type="d4f16f75:AndroidResFolderNode" />
               <item name="color" type="ddeffd01:AndroidResFolderTypeNode" />
             </path>
+            <path>
+              <item name="src" type="1abcf292:AndroidViewProjectNode" />
+              <item name="app" type="feadf853:AndroidModuleNode" />
+              <item name="res" type="d4f16f75:AndroidResFolderNode" />
+              <item name="layout" type="ddeffd01:AndroidResFolderTypeNode" />
+            </path>
             <path>
               <item name="src" type="1abcf292:AndroidViewProjectNode" />
               <item name="app" type="feadf853:AndroidModuleNode" />
@@ -386,7 +424,14 @@
       <option name="project" value="LOCAL" />
       <updated>1568251630189</updated>
     </task>
-    <option name="localTasksCounter" value="8" />
+    <task id="LOCAL-00008" summary="ziji wu comment">
+      <created>1568271876476</created>
+      <option name="number" value="00008" />
+      <option name="presentableId" value="LOCAL-00008" />
+      <option name="project" value="LOCAL" />
+      <updated>1568271876476</updated>
+    </task>
+    <option name="localTasksCounter" value="9" />
     <servers />
   </component>
   <component name="TodoView">
@@ -565,16 +610,6 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/Contact.java">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="620">
-          <caret line="52" column="17" selection-start-line="52" selection-start-column="17" selection-end-line="52" selection-end-column="17" />
-          <folding>
-            <element signature="imports" expanded="true" />
-          </folding>
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/NotesProvider.java">
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="300">
@@ -582,13 +617,6 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="355">
-          <caret line="49" column="36" lean-forward="true" selection-start-line="49" selection-start-column="36" selection-end-line="49" selection-end-column="36" />
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/app/src/main/java/net/micode/notes/model/Note.java">
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="-1908">
@@ -608,10 +636,35 @@
         </state>
       </provider>
     </entry>
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/Contact.java">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="440">
+          <caret line="52" column="17" selection-start-line="52" selection-start-column="17" selection-end-line="52" selection-end-column="17" />
+          <folding>
+            <element signature="imports" expanded="true" />
+          </folding>
+        </state>
+      </provider>
+    </entry>
     <entry file="file://$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/Notes.java">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="216">
-          <caret line="68" column="39" selection-start-line="68" selection-start-column="39" selection-end-line="68" selection-end-column="39" />
+        <state relative-caret-position="164">
+          <caret line="177" column="40" selection-start-line="177" selection-start-column="40" selection-end-line="177" selection-end-column="40" />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/app/src/main/AndroidManifest.xml">
+      <provider selected="true" editor-type-id="text-editor" />
+      <provider editor-type-id="android-manifest" />
+    </entry>
+    <entry file="file://$PROJECT_DIR$/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="244">
+          <caret line="316" column="8" lean-forward="true" selection-start-line="316" selection-start-column="8" selection-end-line="316" selection-end-column="8" />
+          <folding>
+            <element signature="e#9077#9078#0" expanded="true" />
+            <element signature="e#9134#9135#0" expanded="true" />
+          </folding>
         </state>
       </provider>
     </entry>
diff --git a/src/app/src/main/java/net/micode/notes/data/Notes.java b/src/app/src/main/java/net/micode/notes/data/Notes.java
index 923f395..0365fad 100644
--- a/src/app/src/main/java/net/micode/notes/data/Notes.java
+++ b/src/app/src/main/java/net/micode/notes/data/Notes.java
@@ -66,7 +66,7 @@ public class Notes {
 
 
     /**
-     *该类声明了一系列关于便签的final变量，用于再数据库中标识便签，没有定义方法
+     *该类声明了一系列关于便签的final变量，用于在数据库中标识便签，没有定义方法
      */
     public interface NoteColumns {
         /**
@@ -175,7 +175,7 @@ public class Notes {
     }
 
     /*
-    * 该类声明了一系列关于数据的final变量，没有定义方法
+    * 该类声明了一系列关于数据的final变量，用于在数据库中标识数据项，没有定义方法
     * */
     public interface DataColumns {
         /**
diff --git a/src/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java b/src/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java
index 0b3b80a..6acc949 100644
--- a/src/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java
+++ b/src/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java
@@ -63,7 +63,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," +
             NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
         ")";
-
+    //创建SQL数据表表项，String类型
     private static final String CREATE_DATA_TABLE_SQL =
         "CREATE TABLE " + TABLE.DATA + "(" +
             DataColumns.ID + " INTEGER PRIMARY KEY," +
@@ -78,7 +78,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," +
             DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +
         ")";
-
+    //创建SQL数据库索引
     private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
         "CREATE INDEX IF NOT EXISTS note_id_index ON " +
         TABLE.DATA + "(" + DataColumns.NOTE_ID + ");";
@@ -96,7 +96,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * Decrease folder's note count when move note from folder
+     * 当从文件夹中移除便签时，减少便签数量
      */
     private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
         "CREATE TRIGGER decrease_folder_count_on_update " +
@@ -109,7 +109,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * Increase folder's note count when insert new note to the folder
+     * 当在文件夹中插入便签时，增加便签数量
      */
     private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
         "CREATE TRIGGER increase_folder_count_on_insert " +
@@ -195,7 +195,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         " END";
 
     /**
-     * Move notes belong to folder which has been moved to trash folder
+     * 把文件夹中已经扔到垃圾文件夹的便签删除
      */
     private static final String FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER =
         "CREATE TRIGGER folder_move_notes_on_trash " +
@@ -211,13 +211,21 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         super(context, DB_NAME, null, DB_VERSION);
     }
 
+    /*
+    * 在数据库中添加note表项的方法
+    * @db SQL数据库
+    * */
     public void createNoteTable(SQLiteDatabase db) {
-        db.execSQL(CREATE_NOTE_TABLE_SQL);
+        db.execSQL(CREATE_NOTE_TABLE_SQL);//向数据库中添加便签项
         reCreateNoteTableTriggers(db);
         createSystemFolder(db);
         Log.d(TAG, "note table has been created");
     }
 
+    /*
+    * 便签一被更改或者移动就更新数据库的触发器
+    * @db SQL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");
@@ -263,7 +271,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.insert(TABLE.NOTE, null, values);
 
         /**
-         * create trash folder
+         * 创建垃圾文件夹
          */
         values.clear();
         values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
@@ -271,6 +279,10 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.insert(TABLE.NOTE, null, values);
     }
 
+    /*
+    * 在数据库中创建数据表的方法
+    * @db SQL数据库
+    * */
     public void createDataTable(SQLiteDatabase db) {
         db.execSQL(CREATE_DATA_TABLE_SQL);
         reCreateDataTableTriggers(db);
@@ -278,6 +290,10 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         Log.d(TAG, "data table has been created");
     }
 
+    /*
+    * data一被更改或者删除就更新数据库的触发器
+    * @db SQL数据库
+    * */
     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");
@@ -295,6 +311,10 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         return mInstance;
     }
 
+    /*
+    * 重写SQLLiteHelper方法，在数据库中创建便签与数据表项
+    * @db 数据库
+    * */
     @Override
     public void onCreate(SQLiteDatabase db) {
         createNoteTable(db);