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我正在创建一个执行一些网络调用的小部件。我正在为此使用异步任务。但是在我的 onUpdate() 中，没有创建 ComponentName 对象，产生以下编译器错误：

1)The constructor ComponentName(ListViewWidget,Class<ListViewWidget>) is undefined.
2)The method getInstance(context) in the type AppWidgetManager is not applicable for the arguments(ListViewWidget)

//ListViewWidget.java

public class ListViewWidget extends AppWidgetProvider{

    private static String text=null;
    @Override
    public void onUpdate(Context context, AppWidgetManager appWidgetManager,
            int[] appWidgetIds) {

        super.onUpdate(context, appWidgetManager, appWidgetIds);
        RemoteViews updateViews = new RemoteViews(context.getPackageName(), R.layout.list_layout);
        FetchTask fetchTask=new FetchTask(context);

            //compiler error in the following 2 lines
            ComponentName thisWidget = new ComponentName(this, ListViewWidget.class);
        AppWidgetManager manager = AppWidgetManager.getInstance(this);

        manager.updateAppWidget(thisWidget, updateViews);

        fetchTask.execute();


    }
    public static class FetchTask extends AsyncTask<URL,Integer,String>{

        private Context context;
        public FetchTask(Context context){
            this.context=context;
        }

        @Override
        protected String doInBackground(URL... arg0) {


            HttpHeaders headers = new HttpHeaders();
            headers.add(Constants.ACCEPT_HEADER, Constants.JSON_MIME_TYPE );
            headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
            headers.add(Constants.AUTHORIZATION_HEADER, "Basic ZDNhYWNmNDUwZGQ2YWE5OTJjZmJhNzcwNjc1NjA3MzM6N2NlYmJhMWJmMTRjYjg1OA==");

            DefaultHttpClient client = new DefaultHttpClient();
            HttpGet get = new HttpGet("https://api.paypal.com/v1/stores?view=local&lat=37.3756096&lng=-121.9239449&radius=50&count=20&start_id=1&country_code=US");
            //("http://search.twitter.com/search.json?q=twitter");
            BasicResponseHandler handler = new BasicResponseHandler();
            String response = null;

            Date d=null;
            //SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
            try{

                response = client.execute(get,handler);
                Log.i("TagAkshita","Response-"+response);
                if(response!=null){
                    JSONObject object = new JSONObject(response);
                    JSONArray array = object.getJSONArray("results");
                    if(array.length()>0){
                        JSONObject list = array.getJSONObject(0);
                        text = list.getString("view");
                        Log.i("Stores:","textval"+text);

                    }
                }
            }
            catch(Exception e){
                e.printStackTrace();
            }

            return text;
        }

        protected void onPostExecute(RemoteViews updateViews,Context context) {
            // TODO Auto-generated method stub
            Intent intent=new Intent("android.appwidget.action.APPWIDGET_UPDATE");

            PendingIntent pendingIntent=PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
            updateViews.setTextViewText(R.id.text_view, text);
            updateViews.setOnClickPendingIntent(R.id.next, pendingIntent);


        }       
    }
}
4

1 回答 1

1

ComponentName将 Context 作为参数。你传递给它的this是一个 ListViewWidget。

换行

ComponentName thisWidget = new ComponentName(this, ListViewWidget.class);

和

ComponentName thisWidget = new ComponentName(context, ListViewWidget.class);
于 2013-06-18T00:14:32.460 回答