Question

我想在所有拖动结束后刷新。但是，即使我有号码，我也会NullPointerException。另外，我setContentView()要求一个。我想我有不同的问题。 Fragment的代码如下：

case DragEvent.ACTION_DRAG_ENDED:
     System.out.println(String.valueOf(newGame.getPlayer(1).getHand().getHandSize()));
     kyleNum.setText(String.valueOf(newGame.getPlayer(1).getHand().getHandSize()));
break;

我的崩溃日志是：

 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference
                  at android.example.com.sevens.GameActivity$MyDragListener.onDrag(GameActivity.java:413)
                  at android.view.View.dispatchDragEvent(View.java:19809)
                  at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1423)
                  at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1423)
                  at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1423)
                  at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1423)
                  at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1423)
                  at android.view.ViewGroup.dispatchDragEvent(ViewGroup.java:1423)
                  at android.view.ViewRootImpl.handleDragEvent(ViewRootImpl.java:5488)
                  at android.view.ViewRootImpl.access$1000(ViewRootImpl.java:108)
                  at android.view.ViewRootImpl$ViewRootHandler.handleMessage(ViewRootImpl.java:3624)
                  at android.os.Handler.dispatchMessage(Handler.java:102)
                  at android.os.Looper.loop(Looper.java:168)
                  at android.app.ActivityThread.main(ActivityThread.java:5845)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:797)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:687)

Answer 1

如果您的TextView生活在Fragment内，请执行此操作以使代码正常工作：

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_main, container,
            false);
    TextView tv = (TextView) rootView.findViewById(R.id.textView1);
    tv.setText("Teststring");
    return rootView;
}

setText（）文本视图的

1 个答案: