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android:npe,同时尝试用action_appwidget_选择意图为结果进行活动

android-intent android java

Nikolay Ivanov · 技术社区 · 15 年前

我有一个问题,那就是试图 AppWidgetManager.ACTION_APPWIDGET_PICK 正如我从日志中看到的那样,Android AppWidget生态系统中有一个问题。所以我做错了?
参见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);
    }
}

日志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)

另一个小问题是,com.android.settings生活在哪个android项目中?(我被窗户卡住了,所以不能不幸地使用repo) 帮助真正理解。

3 回复 | 直到 14 年前

Nikolay Ivanov 15 年前

看起来像是Android设置中的一个bug,如果你试图在没有指定任何额外小部件的情况下选择AppWidget,你会失败的,请在Google代码中填写一个问题。 link

JRL 15 年前

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

原始答案 :

你应该叫活动的 onClick 在你的超控中。

来自安卓 docs :“ 任何活动生命周期方法的实现都应首先调用超类版本 .

希望能解决问题。

mylock 14 年前

是否确定了解决方案?我见过一些应用程序实现了AppWidget选择器以在其活动中运行AppWidget主机,现在我正收到一个确切的错误,说明没有额外的自定义_信息。我正在测试从发射器源代码使用这个的一些东西,如果我能解决这个错误,至少会报告回来。