AsyncTask 中的 ProgressDialog [英] ProgressDialog in AsyncTask

问题描述

我试图在从 HTTP 服务器加载 RSS 提要时显示自定义进度对话框，我进行了艰难的搜索，但没有任何帮助我做到这一点，我唯一知道的是该解决方案应该使用 AsyncTask，但我对传递给这个 AsyncTask 的参数感到困惑.这是我的活动:

I'm trying to display a custom progressdialog while loading RSS feed from an HTTP server, I made a hard search, but nothing helped me to do this, the only thing I know is that the solution should use AsyncTask, but I'm confusing about the params to pass to this AsyncTask. Here's my activity :

public class Soirees extends ListActivity {

    private List<Message> messages;
    private TextView tvSorties;
    private MyProgressDialog dialog;

    @Override
    public void onCreate(Bundle icicle) {

        super.onCreate(icicle);
        setContentView(R.layout.sorties);

        tvSorties=(TextView)findViewById(R.id.TVTitle);
        tvSorties.setText("Programme des soirées");

        loadFeed();

    }

    private void loadFeed(){

        try{
            BaseFeedParser parser = new BaseFeedParser();
            messages = parser.parse();
            List<Message> titles = new ArrayList<Message>(messages.size());
            for (Message msg : messages){
                titles.add(msg);
            }
            MessageListAdapter adapter = new MessageListAdapter(this,titles);
            this.setListAdapter(adapter);
            adapter.notifyDataSetChanged();

        } catch (Throwable t){
            Log.e("ImageLoader",t.getMessage(),t);
        }
    }

}

你能帮我添加AsyncTask吗?

推荐答案

通过将视图修饰符移动到 onPostExecute 进行修复，因此固定代码为:

Fixed by moving the view modifiers to onPostExecute so the fixed code is :

public class Soirees extends ListActivity {
    private List<Message> messages;
    private TextView tvSorties;

    //private MyProgressDialog dialog;
    @Override
    public void onCreate(Bundle icicle) {

        super.onCreate(icicle);

        setContentView(R.layout.sorties);

        tvSorties=(TextView)findViewById(R.id.TVTitle);
        tvSorties.setText("Programme des soirées");

        new ProgressTask(Soirees.this).execute();


   }


    private class ProgressTask extends AsyncTask<String, Void, Boolean> {
        private ProgressDialog dialog;
        List<Message> titles;
        private ListActivity activity;
        //private List<Message> messages;
        public ProgressTask(ListActivity activity) {
            this.activity = activity;
            context = activity;
            dialog = new ProgressDialog(context);
        }



        /** progress dialog to show user that the backup is processing. */

        /** application context. */
        private Context context;

        protected void onPreExecute() {
            this.dialog.setMessage("Progress start");
            this.dialog.show();
        }

            @Override
        protected void onPostExecute(final Boolean success) {
                List<Message> titles = new ArrayList<Message>(messages.size());
                for (Message msg : messages){
                    titles.add(msg);
                }
                MessageListAdapter adapter = new MessageListAdapter(activity, titles);
                activity.setListAdapter(adapter);
                adapter.notifyDataSetChanged();

                if (dialog.isShowing()) {
                dialog.dismiss();
            }

            if (success) {
                Toast.makeText(context, "OK", Toast.LENGTH_LONG).show();
            } else {
                Toast.makeText(context, "Error", Toast.LENGTH_LONG).show();
            }
        }

        protected Boolean doInBackground(final String... args) {
            try{    
                BaseFeedParser parser = new BaseFeedParser();
                messages = parser.parse();


                return true;
             } catch (Exception e){
                Log.e("tag", "error", e);
                return false;
             }
          }


    }

}

@Vladimir，谢谢你的代码很有帮助.

@Vladimir, thx your code was very helpful.

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