小部件是空的。 使用retrofit获取listview中的数据

Question

I am trying to display data using retrofit inside of a widget using listview. I have checked the logs in the android studio, there are no error. App is fetching the data using retrofit. There is no issue getting data. Can someone please look at it and tell me what I have doing wrong.

App Widgete provider class

public class ExampleAppWidgetProvider extends AppWidgetProvider {


static void updateAppWidget(Context context,AppWidgetManager appWidgetManager,int appWidgetId){
    RemoteViews views = getlistView(context,appWidgetId);
    appWidgetManager.updateAppWidget(appWidgetId,views);
}

static RemoteViews getlistView(Context context, int appWidgetId){
    RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.example_widget);
    Intent intent = new Intent(context,ExampleWidgetService.class);
    intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID,appWidgetId);
    views.setEmptyView(R.id.example_widget_stack_view,R.id.example_widget_empty_view);
    views.setRemoteAdapter(R.id.example_widget_stack_view,intent);

    Intent launchIntent = new Intent(context,MainActivity.class);
    PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, launchIntent,PendingIntent.FLAG_UPDATE_CURRENT );
    views.setPendingIntentTemplate(R.id.example_widget_stack_view,pendingIntent);
    return views;
}

@Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
    for (int appWidgetId : appWidgetIds) {
       updateAppWidget(context,appWidgetManager,appWidgetId);
    }
}

}

This is RemoteViewsFactory class

public class ExampleWidgetItemFactory implements RemoteViewsService.RemoteViewsFactory {

private Context mContext;
private List<Articles> articlesList = new ArrayList<>();
private News news;

public ExampleWidgetItemFactory(Context applicationContext) {
    mContext = applicationContext;
}

private void getData(){
    ApiService apiService = ApiClient.getRetrofit().create(ApiService.class);
    Call<News> call = apiService.getheadlines("us","");
    call.enqueue(new Callback<News>() {
        @Override
        public void onResponse(Call<News> call, Response<News> response) {
            news = response.body();
            assert news != null;
            articlesList = news.getArticles();
            Log.i("ExampleWidgetService", news.getStatus());
        }

        @Override
        public void onFailure(Call<News> call, Throwable t) {
            Log.i("ExampleWidgetService",t.getMessage());
        }
    });
}

@Override
public void onCreate() {

}

@Override
public void onDataSetChanged() {
    getData();
}

@Override
public void onDestroy() {
    articlesList.clear();
}

@Override
public int getCount() {
    if (articlesList == null){
        return 0;
    }
    return articlesList.size();
}

@Override
public RemoteViews getViewAt(int position) {
    RemoteViews remoteViews = new RemoteViews(mContext.getPackageName(), R.layout.example_widget_item);
    remoteViews.setTextViewText(R.id.example_widget_item_text,articlesList.get(position).getTitle());

    Intent fillInIntent = new Intent();
    remoteViews.setOnClickFillInIntent(R.id.example_widget_item_text, fillInIntent);
    return remoteViews;
}

@Override
public RemoteViews getLoadingView() {
    return null;
}

@Override
public int getViewTypeCount() {
    return 1;
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public boolean hasStableIds() {
    return true;
}

}

Answer 1

onDataSetChanged only works well with synchronous (blocking) calls. The Retrofit call is asynchronous by nature so it wouldn't work. What you need to do is send a message containing the data (using either a LocalBroadcastManager or libraries like EventBus ) from the RemoteViewsFactory class to the AppWidgetProvider class to have the system manually refresh the widget for you.