Question

I get crash when i’m trying to run function doTask() in the background. I was trying with new Thread(new Runnable() {}) and it works only this section:
handlerForBar.post(new Runnable() {public void run() { doTask(); } })
but the progressBar appears when the work of doTask() is finished. So I thought that AsyncTask could work, but it crashes.

  public void doTask() 
                {

                ListView listView = (ListView)findViewById(R.id.list);

                myArray = new ArrayList<HashMap<String,Object>>();
                HashMap<String, Object> hash_map;

                hash_map = new HashMap<String, Object>();
                hash_map.put(NICK_KEY, "nick");

                myArray.add(hash_map);
                listView.setAdapter(new myListAdapter(myArray,this));
                new myListAdapter(myArray,this).notifyDataSetChanged();
                }



private class myThread extends AsyncTask<String, Void, String> {

          @Override
          protected String doInBackground(String... params) {

              doTask(); //try, catch also FC
            return null;
          }

          ...
         }

Structure of *.java:

> public class mainActivity extends Activity{}
>                       public void onCreate()
>                                  new myThread().execute("");    
>                       public void doTask()
>                       private class myThread extends AsyncTask<String, Void, String>{}
>                                  protected String doInBackground()
>                                                   doTask()
>                       private class myListView extends BaseAdapter

Answer 1

You can’t touch the UI in doInBackground, you have to update the UI in methods like onProgressUpdate or onPostExecute. See here