我有一个问题，然后尝试用 AppWidgetManager.ACTION_APPWIDGET_PICK 放置一个 Intent ，正如我从日志中看到的那样，android AppWidget 生态系统内部存在问题。
那我做错了吗？
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)
另外一个小问题，com.android.settings 在哪个android 项目中？ (我被 Windows 困住了，所以不幸的是不能使用 repo) 非常感谢您的帮助。
最佳答案
看起来像是 android 设置中的一个错误，如果您尝试在没有指定任何额外小部件的情况下选择 appwidget，您将会失败，请在 google code link 处填写一个问题
关于java - Android:NPE 在尝试使用 ACTION_APPWIDGET_PICK Intent 进行 activityForResult 时，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/1573966/