Question

I use asynctask to get data from web services. But progessdialog not show when thread execute

private class Task_Bank extends AsyncTask<Void, Void, ArrayList<String>>{
        @Override
        protected ArrayList<String> doInBackground(Void... params) {
            ArrayList<String> arrayBankL = new ArrayList<String>();
            String url="http://qhoang.org/webservices/get_list_bank.php";
            JSONParser jsonParser = new JSONParser();
            JSONObject jsonObject = jsonParser.getJSONFromURL(url);
            int i = 0;
            try{
                JSONArray array_bank = jsonObject.getJSONArray("list_bank");
                for(i=0;i<array_bank.length();i++){
                    JSONObject node = array_bank.getJSONObject(i);
                    JSONObject c = node.getJSONObject("node_list_bank");
                    String namebank = c.getString("tennganhang");
                    arrayBankL.add(namebank);
                }
            }catch(JSONException e){
                e.printStackTrace();
            }
            return arrayBankL;
        }

        @Override
        protected void onPostExecute(ArrayList<String> result) {
            ArrayAdapter<String> arrayAdapter_bank = new ArrayAdapter<String>(TaskAActivity.this,android.R.layout.simple_spinner_item,result);
            arrayAdapter_bank.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            spn_bank.setAdapter(arrayAdapter_bank);
        }

        @Override
        protected void onProgressUpdate(Void... values) {
            ProgressDialog MyDialog = ProgressDialog.show( TaskAActivity.this, " " , " Loading. Please wait ... ", true);
        }   
}

OnCreate()

Task_Bank a = new Task_Bank();
a.execute();

JSONParser is class i code to use parser JSON from webservices result.

Answer 1

You should show() dialog in onPreExecute() that starts before task starting and is right place for this. in onProgressUpdate you should only increment progress for your ProgressDialog. and when task finished so in onPostExecute() call MyDialog.dismiss()

@Override
protected void onPreExecute() {
   progressDialog.show();           
}

It could be like this

ProgressDialog MyDialog = ProgressDialog.show(TaskAActivity.this, " " , " Loading. Please wait ... ", true);
// some settings
Task_Bank a = new Task_Bank();
a.execute();

@Override
   protected void onPreExecute() {
      MyDialog.show();          
}