CursorIndexOutOfBoundsException：请求索引0，大小为0.错误 - Android

我试图在一个expandableListView中获取一个子级的位置id，并根据点击的子级启动另一个类，并且正在执行此操作像这样：CursorIndexOutOfBoundsException：请求索引0，大小为0.错误 - 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); 
    }

但我不断收到此错误：

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

这是我送的ID来：

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(); 
    }

下面是对上面的查询：

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

为什么会出现这个错误？我在这里做错了什么？

在此先感谢。

来源

2012-01-05 user990230

这是因为您在Cursor中没有获得任何行。确保fetchRow（...）确实返回一些数据。是String类型的日期字段？

来源

2012-01-05 18:36:02 kosa

是的，日期字段是一个字符串。我检查了光标计数，它是0，所以这就是发生这种错误的原因。我怎么能从被点击的孩子身上获得ID并将其传递给SavedEntries.class？ – user990230 2012-01-05 19:12:22

调试并查看id是否在onChildClick方法中获得了所需的值。 – kosa 2012-01-05 19:19:22

由于某种原因，当onChildClick被调用时，groupPosition，childPosition和id都会得到一个0值。 – user990230 2012-01-05 19:34:24

游标位于空位置。循环游标以获取行。

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

来源

2016-09-29 08:32:42

CursorIndexOutOfBoundsException：请求索引0，大小为0.错误 - Android

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