android - 无法从 AppWidgetProvider 类中的线程 toast

Question

我有一个 appwidget，它可以通过单击从 Web 服务(在 onReceive() 的线程中)下载一些数据。完成后，小部件的 GUI 将在 updateWidget(...) 中更新(= 重新绘制)。

完成后我想 toast 。我尝试了很多方法，比如在 updateWidget(...) 结束时通过将上下文从线程传递到 toast 来 toast ，但这没有用。问题似乎是上下文。因为我的类继承自 AppWidgetProvider 而不是 Activity 我不能使用像 getApplicationContext() 这样的东西。我想我只需要为 toast 找到正确的上下文，但我不知道该怎么做。

相关代码如下:

@Override
public void onReceive(Context context, Intent intent)
{
    //  Name of the action of the intent
    final String action = intent.getAction();

    //  This way the context and the intent can be used in the thread
    final Context ctx = context;
    final Intent i = intent;

    if (action.equals(COUNT_DOWN) == true || action.equals(COUNT_UP) == true)
    {
        //  Show toast to inform the user that this feature is only available in the full version
        Toast.makeText(context, R.string.no_groupchange, Toast.LENGTH_SHORT).show();
    }

    // Update current group
    else if (action.equals(UPDATE_WIDGET))
    {
        // Check for internet connection
        if (isOnline(context) == true)
        {
            //  Show toast to inform the user that refreshing the data has started
            Toast.makeText(context, R.string.refreshing, Toast.LENGTH_SHORT).show();

            //  This way the complete internet communication is independent from the GUI
            //  Also works at low speed internet connection
            Thread myThread = new Thread(new Runnable()
            {
                @Override
                public void run()
                {
                    // TODO Auto-generated method stub
                    int currentGroupOrderID = soapManager.getCurrentGroupOrderID(LEAGUE_SC);
                    theGroup = soapManager.getGroup(currentGroupOrderID, LEAGUE_SC, SAISON);
                    nextMatch = soapManager.getNextMatch(LEAGUE_SC);

                    updateWidget(ctx, i);                       
                }
            });

            myThread.start();               
        } 
        else
        {
            Toast.makeText(context, R.string.no_internet, Toast.LENGTH_SHORT).show();
        }
    }

    super.onReceive(context, intent);
}

public void updateWidget(Context context, Intent intent)
{           
    //  Creating remoteViews for updating the widget
    RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget_layout_simple);

    //  Fill the textViews with text
    setTextViewsFromTheGroup(remoteViews);
    setNextMatchTextView(remoteViews);

    //  Update the widget
    ComponentName widget = new ComponentName(context, SoccerWidgetProvider.class);
    AppWidgetManager awm = AppWidgetManager.getInstance(context);
    awm.updateAppWidget(widget, remoteViews);

    //  This way the widget doesn't stop reacting after some time
    final int appWidgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);

    if (appWidgetId != AppWidgetManager.INVALID_APPWIDGET_ID)
    {
        attachIntents(context, remoteViews, appWidgetId);
    }

    //  HERE I WANT TO MAKE A TOAST!!!
}

Answer 1

您需要从 UI 线程调用 Toast.makeText。你可以这样做:

runOnUiThread(new Runnable() {
    public void run()
    {
        Toast.makeText(context, R.string.refreshing, Toast.LENGTH_SHORT).show();
    }
});