将数据从Android应用程序获取到小部件并显示

Question

I have started implementing a widget into an application of mine and I am having some trouble getting the data from the application to the widget.

Here is the code for my widget:

public class ElectricityMonitorWidgetProvider extends AppWidgetProvider {

    public static final String WIDGETTAG = "WidgetMood";

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

        System.out.println("Widget onUpdate called..");

        final int N = appWidgetIds.length;

        // Perform this loop procedure for each App Widget that belongs to this provider
        for (int i=0; i<N; i++) {
            int appWidgetId = appWidgetIds[i];
            System.out.println("In loop. App widget id: "+appWidgetId);
        }
    }    
}

In my widget I have only a textview that I want updated with a number from my application. The application gets this number via a web request.

In the onUpdate() method which runs periodically I want to be able to update that one textview.

I am not sure how to achieve this.

Do I need to implement a helper class that the widget calls and inside that helper class I have the same method as the application uses to receive the data it uses or?

This is my first time implementing a widget. I have read through the guide on widgets on developer.android.com and that helped me get the widget to show on my phone. The only thing I am missing is the functionality that I describe.

Thanks for any help.

Answer 1

put this in your widget updating loop

for (int i=0; i<N; i++) {
  int appWidgetId = appWidgetIds[i];
  int value = i; //replace with actual value eg from SharedPreferences
  RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.your_widget);
  remoteViews.setTextViewText(R.id.text_view, String.valueOf(value)); //assumed that R.layout.your_widget contains a TextView with R.id_text_view id

  appWidgetManager.updateAppWidget(appWidgetId, remoteViews);
  System.out.println("In loop. App widget id: "+appWidgetId);
}

Please note, that this code does not specify any action upon user touching the widget (generally you need to specify a PendingIntent and hook it with RemoteViews.setOnClickPendingIntent method).

Also, I would suggest that you update your widget when needed and not periodically eg your app could send custom Intent to your AppWidgetProvider, which would handle it in overridden onReceive() and update RemoteViews on widgets.