創建活動時崩潰

我在更改爲應用程序中的單獨活動時遇到了一些問題。被叫活動添加到清單，所以這是沒有問題的（本來是太容易了，對不對？）創建活動時崩潰

這是我的主要活動，調用麻煩的活動：

public class MainMenu extends Activity { 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main_menu); 
} 

public void onBtnClick(final View view) { 
    Intent intent = null; 
    switch (view.getId()) { 
    case R.id.btn_Start: 
     ...//Working fine 
     break; 
    case R.id.btn_Options: 
     ...//Also working 
     break; 
    case R.id.btn_Highscores: 
     intent = new Intent(this, ScoresMenu.class); 
     startActivity(intent); 
     break; 
    } 
} 
}

這是被叫活動：

public class ScoresMenu extends Activity { 

String[] content; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_scores_menu); 

    MyDB db = new MyDB(this); 

    ListView lv = (ListView) findViewById(R.id.lv_Scores); 

    content = db.getScores(); 
    //This returns a String[20], currently with one entry at [0] 

    ArrayAdapter<String> scoreList = new ArrayAdapter<String>(this, 
      android.R.layout.simple_list_item_1, content); 
    lv.setAdapter(scoreList); 
    db.close(); 
} 
}

這裏是要求getScores（）：

public String[] getScores() { 

String[] scoreList = new String[20]; 

SQLiteDatabase db = this.getReadableDatabase(); 
Cursor cursor = db.query(
       TABLE_SCORES, 
       new String[] {KEY_ID, KEY_NAME, KEY_X, KEY_Y, KEY_A, KEY_TIME}, 
       null, null, null, null, 
       KEY_TIME + " ASC", 
       null); 

if (cursor.moveToFirst()) { 
    int i = 1; 
    do { 
     String score; 
     String name = cursor.getString(1); 
     int x = Integer.valueOf(cursor.getString(2)); 
     int y = Integer.valueOf(cursor.getString(3)); 
     int a = Integer.valueOf(cursor.getString(4)); 
     String t = cursor.getString(5); 

     if(i < 10) 
      score = "0" + i; 
     else 
      score = "" + i; score = score + ") " + name + " (" + x + "x" + y + " Felder mit " + a + " Minen in " + t + ")"; 

      scoreList[i] = score; i++; 
    } while (cursor.moveToNext()); 
} 
cursor.close(); 
return scoreList; 
} 
}

隨着LogCat我追趕到目前爲止的問題，一切運行，直到過去「lv.setAdapter（scoreList）;」。所以我想有一些錯誤，用得分列表填充的ListView ...

logcat的本身帶給我的以下內容：

03-30 19:04:12.289: W/dalvikvm(9014): threadid=1: thread exiting with uncaught exception (group=0x40d7d8a8) 
03-30 19:04:15.221: E/AndroidRuntime(9014): FATAL EXCEPTION: main 
03-30 19:04:15.221: E/AndroidRuntime(9014): java.lang.NullPointerException 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:394) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.ArrayAdapter.getView(ArrayAdapter.java:362) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.AbsListView.obtainView(AbsListView.java:2340) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.ListView.makeAndAddView(ListView.java:1793) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.ListView.fillDown(ListView.java:678) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.ListView.fillFromTop(ListView.java:739) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.ListView.layoutChildren(ListView.java:1638) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.AbsListView.onLayout(AbsListView.java:2170) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.View.layout(View.java:13846) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.ViewGroup.layout(ViewGroup.java:4466) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1649) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1507) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.LinearLayout.onLayout(LinearLayout.java:1420) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.View.layout(View.java:13846) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.ViewGroup.layout(ViewGroup.java:4466) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.FrameLayout.onLayout(FrameLayout.java:448) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.View.layout(View.java:13846) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.ViewGroup.layout(ViewGroup.java:4466) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1649) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1507) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.LinearLayout.onLayout(LinearLayout.java:1420) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.View.layout(View.java:13846) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.ViewGroup.layout(ViewGroup.java:4466) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.widget.FrameLayout.onLayout(FrameLayout.java:448) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.View.layout(View.java:13846) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.ViewGroup.layout(ViewGroup.java:4466) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2156) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1914) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1134) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4616) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.Choreographer$CallbackRecord.run(Choreographer.java:747) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.Choreographer.doCallbacks(Choreographer.java:567) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.Choreographer.doFrame(Choreographer.java:536) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:733) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.os.Handler.handleCallback(Handler.java:615) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.os.Handler.dispatchMessage(Handler.java:92) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.os.Looper.loop(Looper.java:153) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at android.app.ActivityThread.main(ActivityThread.java:4987) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at java.lang.reflect.Method.invokeNative(Native Method) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at java.lang.reflect.Method.invoke(Method.java:511) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:821) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:584) 
03-30 19:04:15.221: E/AndroidRuntime(9014):  at dalvik.system.NativeStart.main(Native Method) 
03-30 19:04:15.257: I/Process(9014): Sending signal. PID: 9014 SIG: 9

任何人都可以在這裏找出問題？

來源

2013-03-30 Jochen Reinschlüssel

你確定你的內容數組不爲空？打印出來。確保content = db.getScores（）;正在回報你的期望。 –

你打開關閉你的數據庫！ –

告訴我們在你的mydb類中運行的代碼，這很可能是錯誤的來源。 – AndroidPenguin

麻煩是在'內容'傳遞給ArrayAdapter。

嘗試登錄的內容變量，看它是否具有預期值
檢查「DB」的open（）方法被調用

來源

2013-03-30 19:16:43

創建活動時崩潰

回答

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