CursorIndexOutOfBoundsException：請求索引0，大小爲0.錯誤 - Android

我試圖在一個expandableListView中獲取一個子級的位置id，並根據點擊的子級啓動另一個類，並且正在執行此操作像這樣：CursorIndexOutOfBoundsException：請求索引0，大小爲0.錯誤 - Android

@Override 
    public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) 
    { 
     // TODO Auto-generated method stub 
     super.onChildClick(parent, v, groupPosition, childPosition, id); 
     Intent i = new Intent(this, SavedEntries.class); 
     i.putExtra("_id", id); 
     startActivityForResult(i, ACTIVITY_EDIT); 
     return super.onChildClick(parent, v, groupPosition, childPosition, id); 
    }

但我不斷收到此錯誤：

01-05 13:14:28.232: E/AndroidRuntime(316): FATAL EXCEPTION: main 
01-05 13:14:28.232: E/AndroidRuntime(316): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.x17.projects.strikezone/com.x17.projects.strikezone.SavedEntries}: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0 
01-05 13:14:28.232: E/AndroidRuntime(316): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663) 
01-05 13:14:28.232: E/AndroidRuntime(316): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 
01-05 13:14:28.232: E/AndroidRuntime(316): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 
01-05 13:14:28.232: E/AndroidRuntime(316): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 
01-05 13:14:28.232: E/AndroidRuntime(316): at android.os.Handler.dispatchMessage(Handler.java:99) 
01-05 13:14:28.232: E/AndroidRuntime(316): at android.os.Looper.loop(Looper.java:123) 
01-05 13:14:28.232: E/AndroidRuntime(316): at android.app.ActivityThread.main(ActivityThread.java:4627) 
01-05 13:14:28.232: E/AndroidRuntime(316): at java.lang.reflect.Method.invokeNative(Native Method) 
01-05 13:14:28.232: E/AndroidRuntime(316): at java.lang.reflect.Method.invoke(Method.java:521) 
01-05 13:14:28.232: E/AndroidRuntime(316): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
01-05 13:14:28.232: E/AndroidRuntime(316): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
01-05 13:14:28.232: E/AndroidRuntime(316): at dalvik.system.NativeStart.main(Native Method) 
01-05 13:14:28.232: E/AndroidRuntime(316): Caused by: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0 
01-05 13:14:28.232: E/AndroidRuntime(316): at android.database.AbstractCursor.checkPosition(AbstractCursor.java:580) 
01-05 13:14:28.232: E/AndroidRuntime(316): at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:214) 
01-05 13:14:28.232: E/AndroidRuntime(316): at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:41) 
01-05 13:14:28.232: E/AndroidRuntime(316): at com.x17.projects.strikezone.SavedEntries.getDateRow(SavedEntries.java:56) 
01-05 13:14:28.232: E/AndroidRuntime(316): at com.x17.projects.strikezone.SavedEntries.onCreate(SavedEntries.java:48) 
01-05 13:14:28.232: E/AndroidRuntime(316): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
01-05 13:14:28.232: E/AndroidRuntime(316): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627) 
01-05 13:14:28.232: E/AndroidRuntime(316): ... 11 more

這是我送的ID來：

Bundle extras = getIntent().getExtras(); 
mRowId = extras != null ? extras.getLong("_id") : null; 

    private void getDateRow() 
    { 
     Cursor mCursor = mDbHelper.fetchRow(mRowId); 
     date = mCursor.getString(0); //Line 56, this is where the error occurs. 
     mCursor.close(); 
    }

下面是對上面的查詢：

public Cursor fetchRow(long rowId) 
    { 
     Cursor cursor = mDb.rawQuery("SELECT date FROM entry WHERE _id=" + rowId, null); 
     if(cursor != null) 
     { 
      cursor.moveToFirst(); 
     } 
     return cursor; 
    }

爲什麼會出現這個錯誤？我在這裏做錯了什麼？

在此先感謝。

來源

2012-01-05 user990230

這是因爲您在Cursor中沒有獲得任何行。確保fetchRow（...）確實返回一些數據。是String類型的日期字段？

來源

2012-01-05 18:36:02 kosa

是的，日期字段是一個字符串。我檢查了光標計數，它是0，所以這就是發生這種錯誤的原因。我怎麼能從被點擊的孩子身上獲得ID並將其傳遞給SavedEntries.class？ – user990230 2012-01-05 19:12:22

調試並查看id是否在onChildClick方法中獲得了所需的值。 – kosa 2012-01-05 19:19:22

由於某種原因，當onChildClick被調用時，groupPosition，childPosition和id都會得到一個0值。 – user990230 2012-01-05 19:34:24

遊標位於空位置。循環遊標以獲取行。

while(mCursor.moveToNext()) { 
    date = mCursor.getString(0); 
}

來源

2016-09-29 08:32:42

CursorIndexOutOfBoundsException：請求索引0，大小爲0.錯誤 - Android

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