Android設備上的IndexOutOfBoundsException錯誤不在仿真器上

Question

以下是我現在正在處理Android應用程序的問題。程序在模擬器上工作正常，沒有任何錯誤，但是在運行相同操作系統的真實設備上出錯

1. 我有一個App Widget Update Service來更新我的Widget。該服務檢查小部件是否在屏幕上，否則不會通過更新過程。在模擬器上正常工作。

2. 每次必須在OnReceive方法中更新小部件時，我都會將意圖捕獲到字符串變量check_intent中，告訴我它的ENABLED，DELETED或UPDATE意圖。

3. 我有一個SQLite表tuuserid_widget_enabled只有一個字段啓用。當意圖啓用時，我將其切換爲1，當刪除時，我將它切換爲0.工作正常。

4. 當意圖是更新時，我檢查數據庫表中的啓用字段是否爲1，如果爲真，則繼續進行更新。這是我在設備上得到遊標索引超出界限的錯誤，但是一切都按照預期在仿真器上運行。

我希望對此有所幫助。提前致謝。對不起，如果我做錯了，我只是在學習Android。

以下是錯誤 -

02-02 18:58:03.007: ERROR/AndroidRuntime(4292): FATAL EXCEPTION: main 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): java.lang.RuntimeException: Unable to start service Test.TU.TUWidget$UpdateService@45d2b7d0 with Intent { cmp=Test.TU/.TUWidget$UpdateService }: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3282) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at android.app.ActivityThread.access$3600(ActivityThread.java:135) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2211) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at android.os.Handler.dispatchMessage(Handler.java:99) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at android.os.Looper.loop(Looper.java:144) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at android.app.ActivityThread.main(ActivityThread.java:4937) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at java.lang.reflect.Method.invokeNative(Native Method) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at java.lang.reflect.Method.invoke(Method.java:521) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at dalvik.system.NativeStart.main(Native Method) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292): Caused by: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at android.database.AbstractCursor.checkPosition(AbstractCursor.java:580) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:214) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at android.database.AbstractWindowedCursor.getInt(AbstractWindowedCursor.java:84) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at Test.TU.TUWidget$UpdateService.onStart(TUWidget.java:209) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at android.app.Service.onStartCommand(Service.java:420) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3267) 
02-02 18:58:03.007: ERROR/AndroidRuntime(4292):  ... 10 more 

這裏是代碼片段。

@Override 
    public void onReceive(Context context, Intent intent) { 
     check_intent = intent.getAction(); 
     widgetUpdate.setAction(AppWidgetManager.ACTION_APPWIDGET_UPDATE); 
     AlarmManager alarms = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE); 
     PendingIntent newPending = PendingIntent.getBroadcast(context, 0, widgetUpdate,PendingIntent.FLAG_UPDATE_CURRENT); 
     alarms.set(AlarmManager.ELAPSED_REALTIME, SystemClock.elapsedRealtime()+ PERIOD, newPending); 
     context.startService(new Intent(context, UpdateService.class)); 
} 

public static class UpdateService extends Service { 

     @Override 
     public void onStart(Intent intent, int startId) { 

     if (check_intent.contains("APPWIDGET_ENABLED")){ 
      TUDB tdb = new TUDB(getApplicationContext()); 
      final SQLiteDatabase db = tdb.getReadableDatabase(); 
      String update_sql = "update tuuserid_widget_enabled set enabled = '1';"; 
      if(db.isOpen() && !db.isReadOnly()){ 
       db.execSQL(update_sql); 
       db.close(); 
      } 
     } 
     else 
     **if (check_intent.contains("APPWIDGET_UPDATE")){ 
      TUDB tdb1 = new TUDB(getBaseContext()); 
      final SQLiteDatabase db1 = tdb1.getReadableDatabase(); 
      String check_widget_enabled = "select enabled from tuuserid_widget_enabled;"; 
      if(db1.isOpen() && !db1.isReadOnly()){ 
       Cursor cur = db1.rawQuery(check_widget_enabled, null); 
       cur.moveToFirst(); 
       widget_enabled = cur.getInt(0); //this is where it bombs 
       cur.close(); 
       db1.close(); 
      }** 
      if (widget_enabled == 1){ 
       RemoteViews updateViews = buildUpdate(getApplicationContext()); 
          ComponentName thisWidget = new ComponentName(getApplicationContext(), TUWidget.class); 
       AppWidgetManager manager = AppWidgetManager.getInstance(getApplicationContext()); 
       manager.updateAppWidget(thisWidget, updateViews); 
      } 
     } 
     else 
     if (check_intent.contains("APPWIDGET_DELETED")){ 
      TUDB tdb = new TUDB(getBaseContext()); 
      final SQLiteDatabase db = tdb.getReadableDatabase(); 
      String update_sql = "update tuuserid_widget_enabled set enabled = '0';"; 
      if(db.isOpen() && !db.isReadOnly()){ 
       db.execSQL(update_sql); 
       db.close(); 
      } 
     } 

    } 

Answer 1

您的遊標/數據庫可能是空的 - 沒有行。嘗試：

if (cur.moveToFirst()) { // returns false if cursor is empty 
    widget_enabled = cur.getInt(0); 
} else { 
    widget_enabled = 0; 
}