src/main/AndroidManifest.xml

@@ -30,6 +30,12 @@
             android:uiOptions="splitActionBarWhenNarrow"
             android:windowSoftInputMode="adjustPan"
             android:exported="true">
+        </activity>
+
+        <activity
+            android:name=".ui.SplashActivity"
+            android:theme="@style/SplashTheme"
+            android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
@@ -181,6 +187,14 @@
             android:exported="true">
         </activity>
 
+        <activity
+            android:name=".ui.PrivacySpaceActivity"
+            android:configChanges="keyboardHidden|orientation|screenSize"
+            android:theme="@style/NoteTheme"
+            android:windowSoftInputMode="adjustPan"
+            android:exported="true">
+        </activity>
+
         <service
             android:name="net.micode.notes.gtask.remote.GTaskSyncService"
             android:exported="false" >

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

@@ -83,6 +83,14 @@ public class Notes {
     public static final int TYPE_WIDGET_INVALIDE      = -1;  // 无效小部件类型
     public static final int TYPE_WIDGET_2X            = 0;    // 2x2小部件类型
     public static final int TYPE_WIDGET_4X            = 1;    // 4x4小部件类型
+    
+    /**
+     * 隐私空间相关常量
+     * - TYPE_PRIVACY_SPACE：隐私空间类型
+     * - ID_PRIVACY_SPACE_FOLDER：隐私空间根文件夹ID
+     */
+    public static final int TYPE_PRIVACY_SPACE = 4;  // 隐私空间类型
+    public static final int ID_PRIVACY_SPACE_FOLDER = -4;  // 隐私空间根文件夹ID
 
     /**
      * 数据类型常量类，定义了不同类型的便签数据
@@ -273,6 +281,12 @@ public class Notes {
          * <P> 类型: INTEGER </P>
          */
         public static final String DATA1 = "data1";
+        
+        /**
+         * 隐私空间ID，用于标识便签所属的隐私空间
+         * <P> 类型: TEXT </P>
+         */
+        public static final String PRIVACY_SPACE_ID = "privacy_space_id";
     }
 
     /**

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

@@ -36,7 +36,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     private static final String DB_NAME = "note.db";
 
     // 数据库版本号
-    private static final int DB_VERSION = 10;
+    private static final int DB_VERSION = 11;
 
     // 数据库表名定义
     public interface TABLE {
@@ -96,7 +96,8 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
                     NoteColumns.IS_LOCKED + " INTEGER NOT NULL DEFAULT 0," +
                     NoteColumns.LOCK_PASSWORD + " TEXT NOT NULL DEFAULT ''," +
                     NoteColumns.TAGS + " TEXT NOT NULL DEFAULT ''," +
-                    NoteColumns.DATA1 + " INTEGER NOT NULL DEFAULT 0" +
+                    NoteColumns.DATA1 + " INTEGER NOT NULL DEFAULT 0," +
+                    NoteColumns.PRIVACY_SPACE_ID + " TEXT NOT NULL DEFAULT ''" +
                     ")";
 
     // 创建数据表的SQL语句
@@ -328,6 +329,12 @@ 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);
+        
+        // 创建隐私空间根文件夹：用于存储隐私空间
+        values.clear();
+        values.put(NoteColumns.ID, Notes.ID_PRIVACY_SPACE_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
     }
 
     /**
@@ -448,6 +455,11 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
             upgradeToV10(db);
             oldVersion++;
         }
+        
+        if (oldVersion == 10) {
+            upgradeToV11(db);
+            oldVersion++;
+        }
 
         if (reCreateTriggers) {
             reCreateNoteTableTriggers(db);
@@ -580,4 +592,20 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.DATA1
                 + " INTEGER NOT NULL DEFAULT 0");
     }
+    
+    /**
+     * 将数据库从v10升级到v11
+     * 此版本升级添加了PRIVACY_SPACE_ID字段，用于存储便签所属的隐私空间ID
+     * @param db SQLite数据库实例
+     */
+    private void upgradeToV11(SQLiteDatabase db) {
+        // 为笔记表添加PRIVACY_SPACE_ID字段
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.PRIVACY_SPACE_ID
+                + " TEXT NOT NULL DEFAULT ''");
+        // 添加隐私空间根文件夹
+        ContentValues values = new ContentValues();
+        values.put(NoteColumns.ID, Notes.ID_PRIVACY_SPACE_FOLDER);
+        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
+        db.insert(TABLE.NOTE, null, values);
+    }
 }

src/main/java/net/micode/notes/model/WorkingNote.java

@@ -132,6 +132,11 @@ public class WorkingNote {
      * 标题，便签的标题
      */
     private String mTitle;
+    
+    /**
+     * 隐私空间ID，用于标识便签所属的隐私空间
+     */
+    private String mPrivacySpaceId;
 
     /**
      * 数据投影数组，用于从数据库中查询便签数据
@@ -160,7 +165,8 @@ public class WorkingNote {
             NoteColumns.LOCK_PASSWORD, // 锁定密码
             NoteColumns.PASSWORD_TYPE, // 密码类型
             NoteColumns.NUMERIC_PASSWORD, // 数字密码
-            NoteColumns.TITLE          // 标题
+            NoteColumns.TITLE,         // 标题
+            NoteColumns.PRIVACY_SPACE_ID // 隐私空间ID
     };
 
     /**
@@ -184,6 +190,7 @@ public class WorkingNote {
     private static final int NOTE_PASSWORD_TYPE_COLUMN = 8;       // 密码类型列索引
     private static final int NOTE_NUMERIC_PASSWORD_COLUMN = 9;     // 数字密码列索引
     private static final int NOTE_TITLE_COLUMN = 10;           // 标题列索引
+    private static final int NOTE_PRIVACY_SPACE_ID_COLUMN = 11;    // 隐私空间ID列索引
 
     /**
      * 构造方法，创建一个新的便签
@@ -198,6 +205,7 @@ public class WorkingNote {
         mNote = new Note(); // 创建便签对象
         mNoteId = 0; // 新便签ID为0
         mIsDeleted = false; // 初始化为未删除
+        mPrivacySpaceId = ""; // 初始化为空
         mMode = 0; // 初始化为普通模式
         mWidgetType = Notes.TYPE_WIDGET_INVALIDE; // 初始化为无效小部件类型
     }
@@ -241,6 +249,10 @@ public class WorkingNote {
                 mPasswordType = cursor.getString(NOTE_PASSWORD_TYPE_COLUMN);
                 mNumericPassword = cursor.getString(NOTE_NUMERIC_PASSWORD_COLUMN);
                 mTitle = cursor.getString(NOTE_TITLE_COLUMN);
+                mPrivacySpaceId = cursor.getString(NOTE_PRIVACY_SPACE_ID_COLUMN);
+                if (mPrivacySpaceId == null) {
+                    mPrivacySpaceId = "";
+                }
             }
             cursor.close();
         } else {
@@ -576,6 +588,25 @@ public class WorkingNote {
         return mWidgetType;
     }
 
+    /**
+     * 设置隐私空间ID
+     * @param privacySpaceId 隐私空间ID
+     */
+    public void setPrivacySpaceId(String privacySpaceId) {
+        if (!TextUtils.equals(mPrivacySpaceId, privacySpaceId)) {
+            mPrivacySpaceId = privacySpaceId;
+            mNote.setNoteValue(NoteColumns.PRIVACY_SPACE_ID, privacySpaceId);
+        }
+    }
+
+    /**
+     * 获取隐私空间ID
+     * @return 隐私空间ID
+     */
+    public String getPrivacySpaceId() {
+        return mPrivacySpaceId;
+    }
+
     /**
      * 设置便签锁定状态
      * @param locked 是否锁定

src/main/java/net/micode/notes/ui/NoteEditActivity.java

@@ -300,15 +300,16 @@ public class NoteEditActivity extends Activity implements OnClickListener,
                             | WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE);
         }
         // 处理创建或编辑便签操作
-        else if(TextUtils.equals(Intent.ACTION_INSERT_OR_EDIT, intent.getAction())) {
-            // 获取参数
-            long folderId = intent.getLongExtra(Notes.INTENT_EXTRA_FOLDER_ID, 0);
-            int widgetId = intent.getIntExtra(Notes.INTENT_EXTRA_WIDGET_ID,
-                    AppWidgetManager.INVALID_APPWIDGET_ID);
-            int widgetType = intent.getIntExtra(Notes.INTENT_EXTRA_WIDGET_TYPE,
-                    Notes.TYPE_WIDGET_INVALIDE);
-            int bgResId = intent.getIntExtra(Notes.INTENT_EXTRA_BACKGROUND_ID,
-                    ResourceParser.getDefaultBgId(this));
+            else if(TextUtils.equals(Intent.ACTION_INSERT_OR_EDIT, intent.getAction())) {
+                // 获取参数
+                long folderId = intent.getLongExtra(Notes.INTENT_EXTRA_FOLDER_ID, 0);
+                int widgetId = intent.getIntExtra(Notes.INTENT_EXTRA_WIDGET_ID,
+                        AppWidgetManager.INVALID_APPWIDGET_ID);
+                int widgetType = intent.getIntExtra(Notes.INTENT_EXTRA_WIDGET_TYPE,
+                        Notes.TYPE_WIDGET_INVALIDE);
+                int bgResId = intent.getIntExtra(Notes.INTENT_EXTRA_BACKGROUND_ID,
+                        ResourceParser.getDefaultBgId(this));
+                String privacySpaceId = intent.getStringExtra("privacy_space_id");
 
             // 处理通话记录便签
             String phoneNumber = intent.getStringExtra(Intent.EXTRA_PHONE_NUMBER);
@@ -332,11 +333,19 @@ public class NoteEditActivity extends Activity implements OnClickListener,
                     mWorkingNote = WorkingNote.createEmptyNote(this, folderId, widgetId,
                             widgetType, bgResId);
                     mWorkingNote.convertToCallNote(phoneNumber, callDate);
+                    // 设置隐私空间ID
+                    if (!TextUtils.isEmpty(privacySpaceId)) {
+                        mWorkingNote.setPrivacySpaceId(privacySpaceId);
+                    }
                 }
             } else {
                 // 创建普通新便签
                 mWorkingNote = WorkingNote.createEmptyNote(this, folderId, widgetId, widgetType,
                         bgResId);
+                // 设置隐私空间ID
+                if (!TextUtils.isEmpty(privacySpaceId)) {
+                    mWorkingNote.setPrivacySpaceId(privacySpaceId);
+                }
             }
 
             // 设置软键盘模式为可见状态

src/main/java/net/micode/notes/ui/NotesListActivity.java

@@ -50,6 +50,7 @@ import android.view.View.OnClickListener;
 import android.view.View.OnCreateContextMenuListener;
 import android.view.View.OnTouchListener;
 import android.view.KeyEvent;
+import android.view.ViewGroup;
 import android.view.inputmethod.EditorInfo;
 import android.view.inputmethod.InputMethodManager;
 import android.widget.AdapterView;
@@ -62,8 +63,12 @@ import android.widget.ImageView;
 import android.widget.LinearLayout;
 import android.widget.ListView;
 import android.widget.PopupMenu;
+import android.widget.RelativeLayout;
 import android.widget.TextView;
 import android.widget.Toast;
+import android.widget.GridView;
+import android.widget.BaseAdapter;
+import android.view.ViewGroup;
 
 import net.micode.notes.R;
 import net.micode.notes.data.Notes;
@@ -96,11 +101,23 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
     private static final int MENU_FOLDER_CHANGE_NAME = 2;
 
     private static final String PREFERENCE_ADD_INTRODUCTION = "net.micode.notes.introduction";
+    private static final String PREFERENCE_BACKGROUND = "net.micode.notes.background";
+    private static final String BACKGROUND_TYPE_DEFAULT = "default";
+    private static final String BACKGROUND_TYPE_ALBUM = "album";
+    private static final int REQUEST_CODE_PICK_IMAGE = 105;
 
     private enum ListEditState {
         NOTE_LIST, SUB_FOLDER, CALL_RECORD_FOLDER
     };
 
+    // 背景选项
+    private static final String[] BACKGROUND_OPTIONS = {
+            "高山流水", "风中树叶", "长河落日"
+    };
+    private static final int[] BACKGROUND_RESOURCES = {
+            R.drawable.background_mountain, R.drawable.background_leaves, R.drawable.background_sunset
+    };
+
     private ListEditState mState;
 
     private BackgroundQueryHandler mBackgroundQueryHandler;
@@ -110,6 +127,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
     private ListView mNotesListView;
 
     private Button mAddNewNote;
+    private Button mPrivacyBackButton;
 
     private boolean mDispatch;
 
@@ -135,6 +153,10 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
 
     private static final String ROOT_FOLDER_SELECTION = "(" + NoteColumns.TYPE + "<>" + Notes.TYPE_SYSTEM + " AND " + NoteColumns.TYPE + "<>" + Notes.TYPE_TODO + " AND " + NoteColumns.PARENT_ID + "=?) OR (" + NoteColumns.ID + "=" + Notes.ID_CALL_RECORD_FOLDER + " AND " + NoteColumns.NOTES_COUNT + ">0)";
 
+    // 隐私空间相关常量
+    private static final int REQUEST_CODE_PRIVACY_SPACE = 104;
+    private String mCurrentPrivacySpaceId = "";
+
     private final static int REQUEST_CODE_OPEN_NODE = 102;
     private final static int REQUEST_CODE_NEW_NODE  = 103;
 
@@ -146,11 +168,30 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
     private String mSearchQuery;
     private boolean mIsSearching;
 
+    // 背景相关变量
+    private View mRootView;
+    private RelativeLayout mBackgroundContainer;
+    private LinearLayout mMainContent;
+    private String mCurrentBackgroundType = BACKGROUND_TYPE_DEFAULT;
+    private int mCurrentBackgroundResource = R.drawable.list_background;
+    private String mCurrentBackgroundPath = "";
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.note_list);
+
+        // 获取隐私空间ID
+        Intent intent = getIntent();
+        if (intent != null) {
+            mCurrentPrivacySpaceId = intent.getStringExtra("privacy_space_id");
+            if (mCurrentPrivacySpaceId == null) {
+                mCurrentPrivacySpaceId = "";
+            }
+        }
+
         initResources();
+        initBackground();
 
         /**
          * Insert an introduction when user firstly use this application
@@ -160,9 +201,36 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
 
     @Override
     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
-        if (resultCode == RESULT_OK
-                && (requestCode == REQUEST_CODE_OPEN_NODE || requestCode == REQUEST_CODE_NEW_NODE)) {
-            mNotesListAdapter.changeCursor(null);
+        if (resultCode == RESULT_OK) {
+            if (requestCode == REQUEST_CODE_OPEN_NODE || requestCode == REQUEST_CODE_NEW_NODE) {
+                mNotesListAdapter.changeCursor(null);
+            } else if (requestCode == REQUEST_CODE_PRIVACY_SPACE) {
+                // 处理从隐私空间返回的结果
+                if (data != null) {
+                    String privacySpaceId = data.getStringExtra("privacy_space_id");
+                    if (!TextUtils.isEmpty(privacySpaceId)) {
+                        mCurrentPrivacySpaceId = privacySpaceId;
+                        updatePrivacySpaceUI();
+                        startAsyncNotesListQuery();
+                    }
+                }
+            } else if (requestCode == REQUEST_CODE_PICK_IMAGE) {
+                // 处理从相册选择图片的结果
+                if (data != null && data.getData() != null) {
+                    try {
+                        // 保存图片路径
+                        mCurrentBackgroundType = BACKGROUND_TYPE_ALBUM;
+                        mCurrentBackgroundPath = data.getData().toString();
+                        // 更新背景
+                        updateBackground();
+                        // 保存设置
+                        saveBackgroundSetting();
+                    } catch (Exception e) {
+                        e.printStackTrace();
+                        Toast.makeText(this, "图片加载失败", Toast.LENGTH_SHORT).show();
+                    }
+                }
+            }
         } else {
             super.onActivityResult(requestCode, resultCode, data);
         }
@@ -290,13 +358,46 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         mAddNewNote = (Button) findViewById(R.id.btn_add_note);
         mAddNewNote.setOnClickListener(this);
         mAddNewNote.setOnTouchListener(new NewNoteOnTouchListener());
+        mPrivacyBackButton = (Button) findViewById(R.id.btn_privacy_back);
+        mPrivacyBackButton.setOnClickListener(this);
         mDispatch = false;
         mDispatchY = 0;
         mOriginY = 0;
         mTitleBar = (TextView) findViewById(R.id.tv_title_bar);
+        mMainContent = (LinearLayout) findViewById(R.id.main_content);
+        // 获取根视图作为背景容器
+        mBackgroundContainer = (RelativeLayout) findViewById(R.id.note_list_root);
+        if (mBackgroundContainer == null) {
+            // 如果找不到，使用content view
+            View contentView = getWindow().getDecorView().findViewById(android.R.id.content);
+            if (contentView instanceof ViewGroup) {
+                ViewGroup contentViewGroup = (ViewGroup) contentView;
+                if (contentViewGroup.getChildCount() > 0) {
+                    View childView = contentViewGroup.getChildAt(0);
+                    if (childView instanceof RelativeLayout) {
+                        mBackgroundContainer = (RelativeLayout) childView;
+                    }
+                }
+            }
+        }
+        // 最后的备用方案
+        if (mBackgroundContainer == null) {
+            // 如果还是找不到，使用整个窗口的装饰视图作为背景容器
+            mBackgroundContainer = new RelativeLayout(this);
+            ViewGroup decorView = (ViewGroup) getWindow().getDecorView();
+            View contentView = decorView.findViewById(android.R.id.content);
+            if (contentView != null) {
+                decorView.removeView(contentView);
+                mBackgroundContainer.addView(contentView);
+                decorView.addView(mBackgroundContainer);
+            }
+        }
         mState = ListEditState.NOTE_LIST;
         mModeCallBack = new ModeCallback();
 
+        // 检查是否处于隐私空间中
+        updatePrivacySpaceUI();
+
         // 初始化界面切换栏
         mNotesTab = (TextView) findViewById(R.id.notes_tab);
         mTodoTab = (TextView) findViewById(R.id.todo_tab);
@@ -711,6 +812,57 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
             }
         }
 
+        // 添加隐私空间筛选条件
+        if (!TextUtils.isEmpty(mCurrentPrivacySpaceId)) {
+            // 在隐私空间中，只显示该隐私空间的便签
+            String privacyCondition = NoteColumns.PRIVACY_SPACE_ID + "=?";
+            if (mCurrentFolderId == Notes.ID_ROOT_FOLDER) {
+                // 根文件夹需要特殊处理
+                if (!TextUtils.isEmpty(mSearchQuery) || !TextUtils.isEmpty(mSelectedTag)) {
+                    // 有搜索关键词或标签的情况
+                    baseSelection = "(" + baseSelection + ") AND " + privacyCondition;
+                } else {
+                    // 没有搜索关键词和标签的情况
+                    baseSelection = "(" + NoteColumns.TYPE + "<>" + Notes.TYPE_SYSTEM + " AND " + NoteColumns.PARENT_ID + "=? AND " + privacyCondition + ")";
+                    // 重新构建参数列表
+                    argsList.clear();
+                    argsList.add(String.valueOf(mCurrentFolderId));
+                    argsList.add(mCurrentPrivacySpaceId);
+                }
+            } else {
+                // 普通文件夹
+                if (!TextUtils.isEmpty(mSearchQuery) || !TextUtils.isEmpty(mSelectedTag)) {
+                    // 有搜索关键词或标签的情况
+                    baseSelection = "(" + baseSelection + ") AND " + privacyCondition;
+                } else {
+                    // 没有搜索关键词和标签的情况
+                    baseSelection = NoteColumns.PARENT_ID + "=? AND " + NoteColumns.TYPE + "<>" + Notes.TYPE_TODO + " AND " + privacyCondition;
+                    // 重新构建参数列表
+                    argsList.clear();
+                    argsList.add(String.valueOf(mCurrentFolderId));
+                    argsList.add(mCurrentPrivacySpaceId);
+                }
+            }
+            if (!TextUtils.isEmpty(mSearchQuery) || !TextUtils.isEmpty(mSelectedTag)) {
+                // 有搜索关键词或标签的情况，需要添加隐私空间ID参数
+                argsList.add(mCurrentPrivacySpaceId);
+            }
+        } else {
+            // 不在隐私空间中，只显示非隐私空间的便签
+            String privacyCondition = "(" + NoteColumns.PRIVACY_SPACE_ID + "='' OR " + NoteColumns.PRIVACY_SPACE_ID + " IS NULL)";
+            if (mCurrentFolderId == Notes.ID_ROOT_FOLDER) {
+                // 根文件夹需要特殊处理
+                baseSelection = "(" + baseSelection + ") AND " + privacyCondition;
+            } else {
+                // 普通文件夹
+                if (baseSelection.contains("AND")) {
+                    baseSelection += " AND " + privacyCondition;
+                } else {
+                    baseSelection += " WHERE " + privacyCondition;
+                }
+            }
+        }
+
         selection = baseSelection;
         selectionArgs = argsList.toArray(new String[argsList.size()]);
 
@@ -769,6 +921,7 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
         Intent intent = new Intent(this, NoteEditActivity.class);
         intent.setAction(Intent.ACTION_INSERT_OR_EDIT);
         intent.putExtra(Notes.INTENT_EXTRA_FOLDER_ID, mCurrentFolderId);
+        intent.putExtra("privacy_space_id", mCurrentPrivacySpaceId);
         this.startActivityForResult(intent, REQUEST_CODE_NEW_NODE);
     }
 
@@ -856,6 +1009,29 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
     public void onClick(View v) {
         if (v.getId() == R.id.btn_add_note) {
             createNewNote();
+        } else if (v.getId() == R.id.btn_privacy_back) {
+            // 从隐私空间返回普通空间
+            mCurrentPrivacySpaceId = "";
+            updatePrivacySpaceUI();
+            startAsyncNotesListQuery();
+        }
+    }
+
+    /**
+     * 更新隐私空间相关的UI元素
+     */
+    private void updatePrivacySpaceUI() {
+        if (!TextUtils.isEmpty(mCurrentPrivacySpaceId)) {
+            // 在隐私空间中，显示隐私空间名称
+            mTitleBar.setText("隐私空间");
+            mTitleBar.setVisibility(View.VISIBLE);
+            // 显示隐私空间返回按钮
+            mPrivacyBackButton.setVisibility(View.VISIBLE);
+        } else {
+            // 不在隐私空间中，隐藏标题栏或显示默认标题
+            mTitleBar.setVisibility(View.GONE);
+            // 隐藏隐私空间返回按钮
+            mPrivacyBackButton.setVisibility(View.GONE);
         }
     }
 
@@ -1060,6 +1236,8 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
             // set sync or sync_cancel
             menu.findItem(R.id.menu_sync).setTitle(
                     GTaskSyncService.isSyncing() ? R.string.menu_sync_cancel : R.string.menu_sync);
+            // 添加背景设置选项
+            addBackgroundMenuItems(menu);
         } else if (mState == ListEditState.SUB_FOLDER) {
             getMenuInflater().inflate(R.menu.sub_folder, menu);
         } else if (mState == ListEditState.CALL_RECORD_FOLDER) {
@@ -1094,6 +1272,19 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
             onSearchRequested();
         } else if (item.getItemId() == R.id.menu_trash) {
             startTrashActivity();
+        } else if (item.getItemId() == R.id.menu_privacy_space) {
+            if (!TextUtils.isEmpty(mCurrentPrivacySpaceId)) {
+                // 从隐私空间返回普通空间
+                Intent intent = new Intent(this, NotesListActivity.class);
+                intent.putExtra("privacy_space_id", "");
+                intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);
+                startActivity(intent);
+                finish();
+            } else {
+                // 打开隐私空间
+                Intent intent = new Intent(this, PrivacySpaceActivity.class);
+                startActivityForResult(intent, REQUEST_CODE_PRIVACY_SPACE);
+            }
         }
         return true;
     }
@@ -1413,4 +1604,150 @@ public class NotesListActivity extends Activity implements OnClickListener, OnIt
 
         builder.show();
     }
+
+    /**
+     * 初始化背景
+     */
+    private void initBackground() {
+        // 加载保存的背景设置
+        SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
+        mCurrentBackgroundType = sp.getString(PREFERENCE_BACKGROUND + "_type", BACKGROUND_TYPE_DEFAULT);
+        mCurrentBackgroundPath = sp.getString(PREFERENCE_BACKGROUND + "_path", "");
+
+        if (BACKGROUND_TYPE_DEFAULT.equals(mCurrentBackgroundType)) {
+            int backgroundIndex = sp.getInt(PREFERENCE_BACKGROUND + "_index", 0);
+            if (backgroundIndex >= 0 && backgroundIndex < BACKGROUND_RESOURCES.length) {
+                mCurrentBackgroundResource = BACKGROUND_RESOURCES[backgroundIndex];
+            }
+        }
+
+        // 更新背景
+        updateBackground();
+    }
+
+    /**
+     * 更新背景
+     */
+    private void updateBackground() {
+        if (mBackgroundContainer == null) {
+            return;
+        }
+
+        try {
+            if (BACKGROUND_TYPE_DEFAULT.equals(mCurrentBackgroundType)) {
+                // 使用默认背景
+                mBackgroundContainer.setBackgroundResource(mCurrentBackgroundResource);
+            } else if (BACKGROUND_TYPE_ALBUM.equals(mCurrentBackgroundType) && !TextUtils.isEmpty(mCurrentBackgroundPath)) {
+                // 使用相册图片作为背景
+                try {
+                    android.graphics.Bitmap bitmap = android.graphics.BitmapFactory.decodeStream(
+                            getContentResolver().openInputStream(android.net.Uri.parse(mCurrentBackgroundPath)));
+                    if (bitmap != null) {
+                        // 计算屏幕尺寸
+                        android.util.DisplayMetrics displayMetrics = new android.util.DisplayMetrics();
+                        getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
+                        int screenWidth = displayMetrics.widthPixels;
+                        int screenHeight = displayMetrics.heightPixels;
+
+                        // 缩放图片以适配屏幕
+                        android.graphics.Bitmap scaledBitmap = android.graphics.Bitmap.createScaledBitmap(
+                                bitmap, screenWidth, screenHeight, true);
+
+                        android.graphics.drawable.BitmapDrawable drawable = new android.graphics.drawable.BitmapDrawable(getResources(), scaledBitmap);
+                        // 设置背景图片的缩放方式
+                        drawable.setTileModeXY(android.graphics.Shader.TileMode.CLAMP, android.graphics.Shader.TileMode.CLAMP);
+                        mBackgroundContainer.setBackground(drawable);
+
+                        // 释放原始 bitmap
+                        if (bitmap != scaledBitmap) {
+                            bitmap.recycle();
+                        }
+                    }
+                } catch (Exception e) {
+                    e.printStackTrace();
+                    Toast.makeText(this, "图片加载失败", Toast.LENGTH_SHORT).show();
+                    // 加载失败时使用默认背景
+                    mBackgroundContainer.setBackgroundResource(R.drawable.list_background);
+                }
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+            // 加载失败时使用默认背景
+            mBackgroundContainer.setBackgroundResource(R.drawable.list_background);
+        }
+    }
+
+    /**
+     * 保存背景设置
+     */
+    private void saveBackgroundSetting() {
+        SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
+        SharedPreferences.Editor editor = sp.edit();
+        editor.putString(PREFERENCE_BACKGROUND + "_type", mCurrentBackgroundType);
+        editor.putString(PREFERENCE_BACKGROUND + "_path", mCurrentBackgroundPath);
+
+        if (BACKGROUND_TYPE_DEFAULT.equals(mCurrentBackgroundType)) {
+            // 找到当前背景资源的索引
+            int index = 0;
+            for (int i = 0; i < BACKGROUND_RESOURCES.length; i++) {
+                if (BACKGROUND_RESOURCES[i] == mCurrentBackgroundResource) {
+                    index = i;
+                    break;
+                }
+            }
+            editor.putInt(PREFERENCE_BACKGROUND + "_index", index);
+        }
+
+        editor.apply();
+    }
+
+    /**
+     * 显示背景选择对话框
+     */
+    private void showBackgroundSelectorDialog() {
+        AlertDialog.Builder builder = new AlertDialog.Builder(this);
+        builder.setTitle("选择背景");
+
+        // 创建背景选项数组，添加从相册选择的选项
+        String[] options = new String[BACKGROUND_OPTIONS.length + 1];
+        System.arraycopy(BACKGROUND_OPTIONS, 0, options, 0, BACKGROUND_OPTIONS.length);
+        options[BACKGROUND_OPTIONS.length] = "从相册选择";
+
+        builder.setItems(options, new DialogInterface.OnClickListener() {
+            @Override
+            public void onClick(DialogInterface dialog, int which) {
+                if (which < BACKGROUND_OPTIONS.length) {
+                    // 选择预设背景
+                    mCurrentBackgroundType = BACKGROUND_TYPE_DEFAULT;
+                    mCurrentBackgroundResource = BACKGROUND_RESOURCES[which];
+                    mCurrentBackgroundPath = "";
+                    updateBackground();
+                    saveBackgroundSetting();
+                    Toast.makeText(NotesListActivity.this, "背景已更新", Toast.LENGTH_SHORT).show();
+                } else {
+                    // 从相册选择
+                    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
+                    intent.setType("image/*");
+                    intent.addCategory(Intent.CATEGORY_OPENABLE);
+                    startActivityForResult(intent, REQUEST_CODE_PICK_IMAGE);
+                }
+            }
+        });
+
+        builder.show();
+    }
+
+    /**
+     * 在菜单中添加背景设置选项
+     */
+    private void addBackgroundMenuItems(Menu menu) {
+        MenuItem backgroundMenu = menu.add(0, 100, 0, "背景设置");
+        backgroundMenu.setOnMenuItemClickListener(new OnMenuItemClickListener() {
+            @Override
+            public boolean onMenuItemClick(MenuItem item) {
+                showBackgroundSelectorDialog();
+                return true;
+            }
+        });
+    }
 }

src/main/java/net/micode/notes/ui/PrivacySpaceActivity.java

@@ -0,0 +1,339 @@
+package net.micode.notes.ui;
+
+import android.app.Activity;
+import android.app.AlertDialog;
+import android.content.Context;
+import android.content.DialogInterface;
+import android.content.Intent;
+import android.content.SharedPreferences;
+import android.os.Bundle;
+import android.preference.PreferenceManager;
+import android.text.Editable;
+import android.text.TextUtils;
+import android.text.TextWatcher;
+import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.LinearLayout;
+import android.widget.TextView;
+import android.widget.Toast;
+
+import net.micode.notes.R;
+import net.micode.notes.tool.LockPasswordUtils;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+
+public class PrivacySpaceActivity extends Activity implements OnClickListener {
+    private static final String TAG = "PrivacySpaceActivity";
+    
+    private static final String PREF_PRIVACY_SPACES = "privacy_spaces";
+    private static final String PREF_CURRENT_SPACE = "current_privacy_space";
+    
+    private LinearLayout mSpacesContainer;
+    private Button mAddSpaceButton;
+    private Button mBackButton;
+    
+    private ArrayList<PrivacySpace> mPrivacySpaces;
+    private SharedPreferences mSharedPreferences;
+    
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.privacy_space_activity);
+        
+        initResources();
+        loadPrivacySpaces();
+        displayPrivacySpaces();
+    }
+    
+    private void initResources() {
+        mSpacesContainer = (LinearLayout) findViewById(R.id.spaces_container);
+        mAddSpaceButton = (Button) findViewById(R.id.btn_add_space);
+        mBackButton = (Button) findViewById(R.id.btn_back);
+        
+        mAddSpaceButton.setOnClickListener(this);
+        mBackButton.setOnClickListener(this);
+        
+        mSharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
+        mPrivacySpaces = new ArrayList<>();
+    }
+    
+    private void loadPrivacySpaces() {
+        // 从SharedPreferences加载隐私空间数据
+        String spacesJson = mSharedPreferences.getString(PREF_PRIVACY_SPACES, "");
+        if (!TextUtils.isEmpty(spacesJson)) {
+            // 解析JSON数据
+            try {
+                // 简单的JSON解析逻辑
+                if (spacesJson.startsWith("[")) {
+                        spacesJson = spacesJson.substring(1, spacesJson.length() - 1);
+                        String[] spaceArray = spacesJson.split("\\},\\{");
+                        for (String spaceStr : spaceArray) {
+                            if (!spaceStr.startsWith("{")) {
+                                spaceStr = "{" + spaceStr;
+                            }
+                            if (!spaceStr.endsWith("}")) {
+                                spaceStr = spaceStr + "}";
+                            }
+                        // 提取id、name和password
+                        String id = extractValue(spaceStr, "id");
+                        String name = extractValue(spaceStr, "name");
+                        String password = extractValue(spaceStr, "password");
+                        if (!TextUtils.isEmpty(id) && !TextUtils.isEmpty(name)) {
+                            mPrivacySpaces.add(new PrivacySpace(id, name, password));
+                        }
+                    }
+                }
+            } catch (Exception e) {
+                Log.e(TAG, "Failed to parse privacy spaces JSON", e);
+                // 解析失败，创建默认隐私空间
+                createDefaultPrivacySpace();
+            }
+        } else {
+            // 如果没有隐私空间，创建一个默认隐私空间
+            createDefaultPrivacySpace();
+        }
+    }
+    
+    private void createDefaultPrivacySpace() {
+        // 使用默认密码"123456"，加密后存储
+        String encryptedPassword = LockPasswordUtils.encryptPassword("123456");
+        PrivacySpace defaultSpace = new PrivacySpace("1", "默认隐私空间", encryptedPassword);
+        mPrivacySpaces.add(defaultSpace);
+        savePrivacySpaces();
+    }
+    
+    private String extractValue(String json, String key) {
+        String pattern = "\"" + key + "\":\"([^\"]*)\"";
+        java.util.regex.Pattern r = java.util.regex.Pattern.compile(pattern);
+        java.util.regex.Matcher m = r.matcher(json);
+        if (m.find()) {
+            return m.group(1);
+        }
+        return "";
+    }
+    
+    private void savePrivacySpaces() {
+        // 将隐私空间数据保存到SharedPreferences
+        StringBuilder jsonBuilder = new StringBuilder();
+        jsonBuilder.append("[");
+        for (int i = 0; i < mPrivacySpaces.size(); i++) {
+            PrivacySpace space = mPrivacySpaces.get(i);
+            jsonBuilder.append("{");
+            jsonBuilder.append("\"id\":\"").append(space.getId()).append("\",");
+            jsonBuilder.append("\"name\":\"").append(space.getName()).append("\",");
+            jsonBuilder.append("\"password\":\"").append(space.getPassword()).append("\"");
+            jsonBuilder.append("}");
+            if (i < mPrivacySpaces.size() - 1) {
+                jsonBuilder.append(",");
+            }
+        }
+        jsonBuilder.append("]");
+        String spacesJson = jsonBuilder.toString();
+        mSharedPreferences.edit().putString(PREF_PRIVACY_SPACES, spacesJson).apply();
+    }
+    
+    private void displayPrivacySpaces() {
+        mSpacesContainer.removeAllViews();
+        
+        for (final PrivacySpace space : mPrivacySpaces) {
+            View spaceItem = LayoutInflater.from(this).inflate(R.layout.privacy_space_item, null);
+            TextView spaceName = (TextView) spaceItem.findViewById(R.id.space_name);
+            Button enterButton = (Button) spaceItem.findViewById(R.id.btn_enter_space);
+            Button deleteButton = (Button) spaceItem.findViewById(R.id.btn_delete_space);
+            
+            spaceName.setText(space.getName());
+            enterButton.setOnClickListener(new OnClickListener() {
+                @Override
+                public void onClick(View v) {
+                    enterPrivacySpace(space);
+                }
+            });
+            
+            deleteButton.setOnClickListener(new OnClickListener() {
+                @Override
+                public void onClick(View v) {
+                    deletePrivacySpace(space);
+                }
+            });
+            
+            mSpacesContainer.addView(spaceItem);
+        }
+    }
+    
+    private void enterPrivacySpace(final PrivacySpace space) {
+        // 显示密码输入对话框
+        final AlertDialog.Builder builder = new AlertDialog.Builder(this);
+        View view = LayoutInflater.from(this).inflate(R.layout.dialog_password_input, null);
+        final EditText passwordEditText = (EditText) view.findViewById(R.id.et_password);
+        
+        builder.setTitle("请输入密码")
+               .setView(view)
+               .setPositiveButton(android.R.string.ok, null)
+               .setNegativeButton(android.R.string.cancel, null);
+        
+        final AlertDialog dialog = builder.create();
+        dialog.show();
+        
+        // 在show()之后获取确定按钮
+        final Button okButton = dialog.getButton(DialogInterface.BUTTON_POSITIVE);
+        
+        // 设置密码输入监听
+        passwordEditText.addTextChangedListener(new TextWatcher() {
+            @Override
+            public void beforeTextChanged(CharSequence s, int start, int count, int after) {}
+            
+            @Override
+            public void onTextChanged(CharSequence s, int start, int before, int count) {
+                if (okButton != null) {
+                    okButton.setEnabled(s.length() > 0);
+                }
+            }
+            
+            @Override
+            public void afterTextChanged(Editable s) {}
+        });
+        
+        // 自定义确定按钮点击事件
+        if (okButton != null) {
+            okButton.setOnClickListener(new OnClickListener() {
+                @Override
+            public void onClick(View v) {
+                String password = passwordEditText.getText().toString();
+                if (verifyPassword(space, password)) {
+                    dialog.dismiss();
+                    // 密码验证成功，进入隐私空间
+                    mSharedPreferences.edit().putString(PREF_CURRENT_SPACE, space.getId()).apply();
+                    
+                    // 设置返回结果并结束活动
+                    Intent resultIntent = new Intent();
+                    resultIntent.putExtra("privacy_space_id", space.getId());
+                    setResult(RESULT_OK, resultIntent);
+                    
+                    // 结束活动，让 NotesListActivity 在 onActivityResult 方法中处理返回结果
+                    finish();
+                } else {
+                    Toast.makeText(PrivacySpaceActivity.this, "密码错误", Toast.LENGTH_SHORT).show();
+                }
+            }
+            });
+        }
+    }
+    
+    private boolean verifyPassword(PrivacySpace space, String password) {
+        // 使用LockPasswordUtils验证密码
+        return LockPasswordUtils.verifyPassword(password, space.getPassword());
+    }
+    
+    private void addPrivacySpace() {
+        // 显示创建隐私空间对话框
+        final AlertDialog.Builder builder = new AlertDialog.Builder(this);
+        View view = LayoutInflater.from(this).inflate(R.layout.dialog_create_space, null);
+        final EditText nameEditText = (EditText) view.findViewById(R.id.et_space_name);
+        final EditText passwordEditText = (EditText) view.findViewById(R.id.et_space_password);
+        
+        builder.setTitle("创建新隐私空间")
+               .setView(view)
+               .setPositiveButton(android.R.string.ok, null)
+               .setNegativeButton(android.R.string.cancel, null);
+        
+        final AlertDialog dialog = builder.create();
+        dialog.show();
+        
+        // 自定义确定按钮点击事件
+        Button okButton = dialog.getButton(DialogInterface.BUTTON_POSITIVE);
+        okButton.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                String name = nameEditText.getText().toString();
+                String password = passwordEditText.getText().toString();
+                
+                if (TextUtils.isEmpty(name)) {
+                    Toast.makeText(PrivacySpaceActivity.this, "请输入空间名称", Toast.LENGTH_SHORT).show();
+                    return;
+                }
+                
+                if (TextUtils.isEmpty(password) || password.length() < 6) {
+                    Toast.makeText(PrivacySpaceActivity.this, "请输入至少6位密码", Toast.LENGTH_SHORT).show();
+                    return;
+                }
+                
+                // 创建新隐私空间，使用LockPasswordUtils加密密码
+                String id = String.valueOf(System.currentTimeMillis());
+                String encryptedPassword = LockPasswordUtils.encryptPassword(password);
+                PrivacySpace newSpace = new PrivacySpace(id, name, encryptedPassword);
+                mPrivacySpaces.add(newSpace);
+                
+                // 保存并显示
+                savePrivacySpaces();
+                displayPrivacySpaces();
+                
+                dialog.dismiss();
+            }
+        });
+    }
+    
+    private void deletePrivacySpace(final PrivacySpace space) {
+        new AlertDialog.Builder(this)
+            .setTitle("删除隐私空间")
+            .setMessage("确定要删除\"" + space.getName() + "\"吗？删除后空间内的所有数据将被清除。")
+            .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
+                @Override
+                public void onClick(DialogInterface dialog, int which) {
+                    mPrivacySpaces.remove(space);
+                    savePrivacySpaces();
+                    displayPrivacySpaces();
+                }
+            })
+            .setNegativeButton(android.R.string.cancel, null)
+            .show();
+    }
+    
+    @Override
+    public void onClick(View v) {
+        if (v.getId() == R.id.btn_add_space) {
+            addPrivacySpace();
+        } else if (v.getId() == R.id.btn_back) {
+            finish();
+        }
+    }
+    
+    private class PrivacySpace {
+        private String mId;
+        private String mName;
+        private String mPassword; // 存储加密后的密码
+        
+        public PrivacySpace(String id, String name) {
+            mId = id;
+            mName = name;
+            mPassword = "";
+        }
+        
+        public PrivacySpace(String id, String name, String password) {
+            mId = id;
+            mName = name;
+            mPassword = password;
+        }
+        
+        public String getId() {
+            return mId;
+        }
+        
+        public String getName() {
+            return mName;
+        }
+        
+        public String getPassword() {
+            return mPassword;
+        }
+        
+        public void setPassword(String password) {
+            mPassword = password;
+        }
+    }
+}

src/main/java/net/micode/notes/ui/SplashActivity.java

@@ -0,0 +1,74 @@
+package net.micode.notes.ui;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.Handler;
+import android.view.animation.Animation;
+import android.view.animation.AnimationUtils;
+import android.widget.ImageView;
+import android.widget.TextView;
+
+import net.micode.notes.R;
+
+public class SplashActivity extends Activity {
+
+    private static final int SPLASH_DURATION = 2000;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.splash_activity);
+
+        initAnimation();
+    }
+
+    private void initAnimation() {
+        ImageView logo = findViewById(R.id.splash_logo);
+        TextView appName = findViewById(R.id.splash_app_name);
+
+        Animation splashAnimation = AnimationUtils.loadAnimation(this, R.anim.splash_animation);
+
+        logo.startAnimation(splashAnimation);
+        appName.startAnimation(splashAnimation);
+
+        splashAnimation.setAnimationListener(new Animation.AnimationListener() {
+            @Override
+            public void onAnimationStart(Animation animation) {
+            }
+
+            @Override
+            public void onAnimationEnd(Animation animation) {
+                navigateToMainActivity();
+            }
+
+            @Override
+            public void onAnimationRepeat(Animation animation) {
+            }
+        });
+
+        new Handler().postDelayed(new Runnable() {
+            @Override
+            public void run() {
+                navigateToMainActivity();
+            }
+        }, SPLASH_DURATION);
+    }
+
+    private void navigateToMainActivity() {
+        Intent intent = new Intent(this, NotesListActivity.class);
+        startActivity(intent);
+        overridePendingTransition(android.R.anim.fade_in, android.R.anim.fade_out);
+        finish();
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        finish();
+    }
+
+    @Override
+    public void onBackPressed() {
+    }
+}

src/main/res/anim/splash_animation.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<set xmlns:android="http://schemas.android.com/apk/res/android"
+    android:duration="2000"
+    android:fillAfter="true">
+
+    <scale
+        android:fromXScale="0.5"
+        android:fromYScale="0.5"
+        android:toXScale="1.0"
+        android:toYScale="1.0"
+        android:pivotX="50%"
+        android:pivotY="50%"
+        android:interpolator="@android:anim/accelerate_decelerate_interpolator" />
+
+    <alpha
+        android:fromAlpha="0.0"
+        android:toAlpha="1.0"
+        android:interpolator="@android:anim/accelerate_interpolator" />
+
+</set>

src/main/res/drawable/ic_arrow_back.xml

@@ -0,0 +1,41 @@
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- 黄色圆形背景 -->
+    <item>
+        <shape android:shape="oval">
+            <solid android:color="#FFC107" />
+            <size
+                android:width="64dp"
+                android:height="64dp" />
+        </shape>
+    </item>
+    <!-- 白色返回箭头 -->
+    <item
+        android:left="24dp"
+        android:right="24dp"
+        android:top="24dp"
+        android:bottom="24dp">
+        <rotate android:fromDegrees="180" android:pivotX="50%" android:pivotY="50%">
+            <shape android:shape="rectangle">
+                <solid android:color="#FFFFFF" />
+                <size
+                    android:width="16dp"
+                    android:height="16dp" />
+            </shape>
+        </rotate>
+    </item>
+    <!-- 白色返回箭头的三角形部分 -->
+    <item
+        android:left="20dp"
+        android:right="28dp"
+        android:top="24dp"
+        android:bottom="24dp">
+        <rotate android:fromDegrees="45" android:pivotX="50%" android:pivotY="50%">
+            <shape android:shape="rectangle">
+                <solid android:color="#FFFFFF" />
+                <size
+                    android:width="16dp"
+                    android:height="16dp" />
+            </shape>
+        </rotate>
+    </item>
+</layer-list>

src/main/res/drawable/ic_privacy_space.xml

@@ -0,0 +1,40 @@
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- 黄色圆形背景 -->
+    <item>
+        <shape android:shape="oval">
+            <solid android:color="#FFC107" />
+            <size
+                android:width="64dp"
+                android:height="64dp" />
+        </shape>
+    </item>
+    <!-- 白色锁图案 -->
+    <item
+        android:left="20dp"
+        android:right="20dp"
+        android:top="20dp"
+        android:bottom="20dp">
+        <shape android:shape="rectangle">
+            <solid android:color="#FFFFFF" />
+            <corners android:radius="4dp" />
+        </shape>
+    </item>
+    <item
+        android:left="28dp"
+        android:right="28dp"
+        android:top="28dp"
+        android:bottom="32dp">
+        <shape android:shape="rectangle">
+            <solid android:color="#FFFFFF" />
+        </shape>
+    </item>
+    <item
+        android:left="24dp"
+        android:right="24dp"
+        android:top="36dp"
+        android:bottom="24dp">
+        <shape android:shape="rectangle">
+            <solid android:color="#FFFFFF" />
+        </shape>
+    </item>
+</layer-list>

src/main/res/layout/dialog_create_space.xml

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="fill_parent"
+    android:layout_height="wrap_content"
+    android:orientation="vertical"
+    android:padding="16dp">
+    
+    <!-- 空间名称输入框 -->
+    <EditText
+        android:id="@+id/et_space_name"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:hint="请输入隐私空间名称"
+        android:inputType="text"
+        android:textSize="16sp"
+        android:padding="12dp"
+        android:background="#FFFFFF"
+        android:layout_marginBottom="16dp" />
+    
+    <!-- 密码输入框 -->
+    <EditText
+        android:id="@+id/et_space_password"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:hint="请输入至少6位密码"
+        android:inputType="textPassword"
+        android:textSize="16sp"
+        android:padding="12dp"
+        android:background="#FFFFFF"
+        android:layout_marginBottom="8dp" />
+    
+    <!-- 提示文本 -->
+    <TextView
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:text="密码长度至少为6位"
+        android:textSize="14sp"
+        android:textColor="#808080"
+        android:gravity="center" />
+</LinearLayout>

src/main/res/layout/dialog_password_input.xml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="fill_parent"
+    android:layout_height="wrap_content"
+    android:orientation="vertical"
+    android:padding="16dp">
+    
+    <!-- 密码输入框 -->
+    <EditText
+        android:id="@+id/et_password"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:hint="请输入密码"
+        android:inputType="textPassword"
+        android:textSize="16sp"
+        android:padding="12dp"
+        android:background="#FFFFFF"
+        android:layout_marginBottom="8dp" />
+    
+    <!-- 提示文本 -->
+    <TextView
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:text="默认密码：123456"
+        android:textSize="14sp"
+        android:textColor="#808080"
+        android:gravity="center" />
+</LinearLayout>

src/main/res/layout/note_list.xml

@@ -17,6 +17,7 @@
 
 <RelativeLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/note_list_root"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
     android:background="@drawable/list_background"
@@ -161,4 +162,20 @@
         android:layout_above="@+id/view_switcher"
         android:layout_marginRight="16dp"
         android:layout_marginBottom="16dp" />
+    
+    <!-- 隐私空间返回按钮 -->
+    <Button
+        android:id="@+id/btn_privacy_back"
+        android:layout_width="120dp"
+        android:layout_height="48dp"
+        android:layout_alignParentLeft="true"
+        android:layout_above="@+id/view_switcher"
+        android:layout_marginLeft="16dp"
+        android:layout_marginBottom="16dp"
+        android:background="#808080"
+        android:text="返回主界面"
+        android:textColor="#FFFFFF"
+        android:textSize="16sp"
+        android:gravity="center"
+        android:visibility="gone" />
 </RelativeLayout>

src/main/res/layout/privacy_space_activity.xml

@@ -0,0 +1,60 @@
+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="fill_parent"
+    android:layout_height="fill_parent"
+    android:background="@drawable/list_background"
+    android:fitsSystemWindows="true"
+    android:paddingTop="24dp">
+    
+    <!-- 标题栏 -->
+    <TextView
+        android:id="@+id/tv_title_bar"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:background="@drawable/title_bar_bg"
+        android:gravity="center_vertical"
+        android:singleLine="true"
+        android:text="隐私空间"
+        android:textColor="#FFEAD1AE"
+        android:textSize="@dimen/text_font_size_medium" />
+    
+    <!-- 隐私空间列表容器 -->
+    <LinearLayout
+        android:id="@+id/spaces_container"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:layout_below="@+id/tv_title_bar"
+        android:layout_above="@+id/btn_add_space"
+        android:orientation="vertical"
+        android:padding="16dp"
+        android:gravity="center_horizontal" />
+    
+    <!-- 添加隐私空间按钮 -->
+    <Button
+        android:id="@+id/btn_add_space"
+        android:layout_width="200dp"
+        android:layout_height="48dp"
+        android:layout_above="@+id/btn_back"
+        android:layout_centerHorizontal="true"
+        android:layout_marginBottom="16dp"
+        android:background="#FFC107"
+        android:text="添加隐私空间"
+        android:textColor="#FFFFFF"
+        android:textSize="16sp"
+        android:gravity="center" />
+    
+    <!-- 返回按钮 -->
+    <Button
+        android:id="@+id/btn_back"
+        android:layout_width="120dp"
+        android:layout_height="48dp"
+        android:layout_alignParentBottom="true"
+        android:layout_alignParentLeft="true"
+        android:layout_marginBottom="32dp"
+        android:layout_marginLeft="16dp"
+        android:background="#808080"
+        android:text="返回主界面"
+        android:textColor="#FFFFFF"
+        android:textSize="16sp"
+        android:gravity="center" />
+</RelativeLayout>

src/main/res/layout/privacy_space_item.xml

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="fill_parent"
+    android:layout_height="wrap_content"
+    android:orientation="horizontal"
+    android:background="#FFFFFF"
+    android:padding="16dp"
+    android:layout_marginBottom="8dp"
+    android:gravity="center_vertical"
+    android:layout_gravity="center_horizontal">
+    
+    <!-- 隐私空间名称 -->
+    <TextView
+        android:id="@+id/space_name"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_weight="1"
+        android:textSize="16sp"
+        android:textColor="#000000"
+        android:gravity="center" />
+    
+    <!-- 进入按钮 -->
+    <Button
+        android:id="@+id/btn_enter_space"
+        android:layout_width="80dp"
+        android:layout_height="36dp"
+        android:background="#FFC107"
+        android:text="进入"
+        android:textColor="#FFFFFF"
+        android:textSize="14sp"
+        android:layout_marginRight="8dp"
+        android:gravity="center" />
+    
+    <!-- 删除按钮 -->
+    <Button
+        android:id="@+id/btn_delete_space"
+        android:layout_width="80dp"
+        android:layout_height="36dp"
+        android:background="#FF5252"
+        android:text="删除"
+        android:textColor="#FFFFFF"
+        android:textSize="14sp"
+        android:gravity="center" />
+</LinearLayout>

src/main/res/layout/splash_activity.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:background="@android:color/white">
+
+    <ImageView
+        android:id="@+id/splash_logo"
+        android:layout_width="120dp"
+        android:layout_height="120dp"
+        android:src="@mipmap/ic_launcher"
+        android:layout_centerInParent="true"
+        android:contentDescription="应用图标" />
+
+    <TextView
+        android:id="@+id/splash_app_name"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/app_name"
+        android:textSize="24sp"
+        android:textColor="@android:color/black"
+        android:layout_below="@id/splash_logo"
+        android:layout_centerHorizontal="true"
+        android:layout_marginTop="20dp" />
+
+</RelativeLayout>

src/main/res/menu/note_list.xml

@@ -40,4 +40,8 @@
     <item
         android:id="@+id/menu_trash"
         android:title="@string/menu_trash"/>
+    
+    <item
+        android:id="@+id/menu_privacy_space"
+        android:title="隐私空间"/>
 </menu>

src/main/res/values/styles.xml

@@ -65,4 +65,10 @@
     <style name="NoteActionBarStyle" parent="@android:style/Widget.Holo.Light.ActionBar.Solid">
         <item name="android:visibility">visible</item>
     </style>
+
+    <style name="SplashTheme" parent="@android:style/Theme.Holo.Light.NoActionBar">
+        <item name="android:windowBackground">@android:color/white</item>
+        <item name="android:windowFullscreen">true</item>
+        <item name="android:windowContentOverlay">@null</item>
+    </style>
 </resources>