Question

我是一位经验丰富的Android程序员。

我有一个列表活动，每个列表项都会打开一个新活动。应用程序中有一个地图，其中显示了位置的气球覆盖。有4个位置，当我点击任何气球覆盖时，我需要相应索引的活动。例如：如果我点击index = 1的气球，我需要在活动中显示列表的第一项。

我目前正在使用以下代码。

@Override
protected boolean onBalloonTap(int index, OverlayItem item) {

    Toast.makeText(c, "onBalloonTap for overlay index " + index,
            Toast.LENGTH_LONG).show();
    int index1 = index;
    Intent i = new Intent(c,FestivalEvents.class);
    i.putExtra("banner", "index1");
    c.startActivity(i);

    return true;
}

我正在捕捉另一个活动的意图，即如下的FestivalEvents.class

Bundle eventExtra = getIntent().getExtras();
    if(eventExtra!=null){
        int position = eventExtra.getInt("banner");
        Log.i("banner", "" + position);
        switch(position){
        case 0: Toast.makeText(mContext, ""+ position, Toast.LENGTH_LONG).show();setUpDesc(position);break;
        case 1:Toast.makeText(mContext, ""+ position,Toast.LENGTH_LONG).show();setUpDesc(position);break;
        case 2:Toast.makeText(mContext, ""+ position, Toast.LENGTH_LONG).show();setUpDesc(position);break;
        case 3:Toast.makeText(mContext, ""+ position, Toast.LENGTH_LONG).show();setUpDesc(position);break;

        }

    }

使用此代码，应用程序崩溃并出现空指针异常。我希望我的代码适合接收意图。或者在处理接收意图时我可能是错的。我很有时间解决这个问题。请问有谁可以告诉我哪里可能出错了？

修改我的logcat：

11-02 18:45:38.858: ERROR/AndroidRuntime(21168): FATAL EXCEPTION: main 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.sysponent.bedford/com.sysponent.bedford.FestivalEvents}: java.lang.NullPointerException 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): at android.os.Handler.dispatchMessage(Handler.java:99) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): at android.os.Looper.loop(Looper.java:130) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): at android.app.ActivityThread.main(ActivityThread.java:3687) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): at java.lang.reflect.Method.invokeNative(Native Method) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): at java.lang.reflect.Method.invoke(Method.java:507) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168):at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168):at dalvik.system.NativeStart.main(Native Method) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): Caused by: java.lang.NullPointerException 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): at com.sysponent.bedford.FestivalEvents.onCreate(FestivalEvents.java:239) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 11-02 18:45:38.858: ERROR/AndroidRuntime(21168):at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1615)

谢谢

Answer 1

i.putExtra("banner", "index1");

不应该是

  i.putExtra("banner", index1);

从地图叠加中打开不同的活动

1 个答案: