Android：尝试使用ACTION_APPWIDGET_PICK意图的activityForResult时的NPE

我有一个问题，然后尝试用AppWidgetManager.ACTION_APPWIDGET_PICK一个问题在Android AppWidget生态系统内部有一个问题，我可以从日志中看到。 这样我做错了？
请参阅下面的示例代码和堆栈跟踪

 public class NPEDemoActivity extends Activity { private final static int HOST_CODE = 1024; private AppWidgetHost host; private AppWidgetManager manager; private int PICK_WIDGET_RC = 1; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); host = new AppWidgetHost(this, HOST_CODE); host.startListening(); manager = AppWidgetManager.getInstance(this); Button b = (Button)findViewById(R.id.Button01); b.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { int nextId = host.allocateAppWidgetId(); Intent pickIntent = new Intent(AppWidgetManager.ACTION_APPWIDGET_PICK); pickIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, nextId); startActivityForResult(pickIntent, PICK_WIDGET_RC); } }); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); } } 

来自log cat的堆栈跟踪：

 10-15 17:33:06.873: ERROR/AndroidRuntime(821): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.settings/com.android.settings.AppWidgetPickActivity}: java.lang.NullPointerException 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2401) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2417) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at android.app.ActivityThread.access$2100(ActivityThread.java:116) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1794) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at android.os.Handler.dispatchMessage(Handler.java:99) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at android.os.Looper.loop(Looper.java:123) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at android.app.ActivityThread.main(ActivityThread.java:4203) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at java.lang.reflect.Method.invokeNative(Native Method) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at java.lang.reflect.Method.invoke(Method.java:521) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at dalvik.system.NativeStart.main(Native Method) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): Caused by: java.lang.NullPointerException 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at com.android.settings.AppWidgetPickActivity.putAppWidgetItems(AppWidgetPickActivity.java:170) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at com.android.settings.AppWidgetPickActivity.putCustomAppWidgets(AppWidgetPickActivity.java:132) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at com.android.settings.AppWidgetPickActivity.getItems(AppWidgetPickActivity.java:208) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at com.android.settings.ActivityPicker.onCreate(ActivityPicker.java:99) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at com.android.settings.AppWidgetPickActivity.onCreate(AppWidgetPickActivity.java:63) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123) 10-15 17:33:06.873: ERROR/AndroidRuntime(821): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2364) 

另一个小问题，com.android.settings中的android项目是哪个？ （我被困在窗户上，所以不能不幸地使用回购）帮助真的很贬值。

Answer 1

看起来像Android设置中的一个错误，如果你试图选择appwidget而没有指定任何额外的小部件，你将失败，在谷歌代码链接填补一个问题

Answer 2

编辑 ：说得太快，没看到它是一个ViewListener方法。 不知道是否还需要。

原始答案 ：

你应该在你的覆盖中调用Acitivy的onClick 。

来自Android 文档 ：“ 任何活动生命周期方法的实现应始终首先调用超类版本 。

希望能解决问题。

Answer 3

你确定了一个解决方法吗？ 我已经看到实现appwidget选择器的应用程序在他们的活动中运行appwidget主机，我现在收到这个确切的错误，说明EXTRA_CUSTOM_INFO不存在。 我正在测试Launcher源代码中的一些用法，并且如果我至少可以解决错误，我会报告。