有时有时无法从小部件启动活动

Question

I have implemented a App Widget to launch my activity when clicked.

onUpdate() method of WidgetProvider :

public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
    super.onUpdate(context, appWidgetManager, appWidgetIds);

    final int N = appWidgetIds.length;
    for (int i=0; i<N; i++) {
        int appWidgetId = appWidgetIds[i];

        RemoteViews updateViews = new RemoteViews(context.getPackageName(), R.layout.mywidgetprovider_layout);
        // ....update updateViews here
        appWidgetManager.updateAppWidget(appWidgetId, updateViews);

        Intent onClickedIntent = new Intent(context,MyActivity.class);
        PendingIntent pi = PendingIntent.getActivity(context, 0, onClickedIntent, 0);
        updateViews.setOnClickPendingIntent(R.id.myView, pi);

        appWidgetManager.updateAppWidget(appWidgetId, updateViews);

     }
}

It work as expected after the widget added on home screen.

But after sometimes, it cannot launch the activity again! I have to remove the widget and add again.

How can I fix it? please help.

Answer 1

I know this is like two years late but I struggled with this too until today when I think I know what I was doing wrong. I think the main key is to focus on the use of the RemoteViews class. You prepare these objects as a sort of instruction set for a another process to follow. Setting the "on click pending intent" must done before sending it to the updateAppWidget method, so your first call to that method won't prime your "myView" object for clicks. Your code next sets the onClick trigger and calls updateAppWidget a second time. It looks like that one should work but there is a whole confusing subject regarding just when two intents are distinct or ambiguous which you may want to read about to understand why your code is working unpredictably. If I'm right, the take-away is to simply not call updateAppWidget the first time and then always make sure to set your onClick trigger whenever creating RemoteViews objects. I hope so anyway.

Answer 2

I'd do it like this:

public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
    RemoteViews updateViews = new RemoteViews(context.getPackageName(), R.layout.mywidgetprovider_layout);    
    Intent onClickedIntent = new Intent(context,MyActivity.class);
    PendingIntent pi = PendingIntent.getActivity(context, 0, onClickedIntent, 0);
    updateViews.setOnClickPendingIntent(R.id.myView, pi);

    for (int i=0; i<appWidgetIds.length; i++) {
        appWidgetManager.updateAppWidget(appWidgetIds[i], updateViews);
     }
}

One thing I'm not sure on is the call to super.onUpdate() . My own widget code doesn't have it and seems to work fine... not sure if it's needed or not.

I don't know if this refactor will fix your issue though!