Use Asynctask to display a ProgressBar in Android

Question

I am trying to do display a ProgressBar.

I am an Android beginner.

When I press the button, the task should be running in the background, but it does not display

Answer 1

You are not calling dialog.show() in onPreExecute method of your AsyncTask.

Answer 2

Use ProgressDialog. You don't need any layout in this case.

ProgressDialog progressDialog = new ProgressDialog(context);

in onPreExecute show it

progressDialog.show();

and in onPostExecute dissmiss it

progressDialog.dismiss();

Answer 3

Add to OnPostExecute method :

pg.setVisibility(View.INVISIBLE);

Add to onPreExecute method :

pg.setVisibility(View.VISIBLE);

and in Layout file you should add to progress bar :

android:visibility="invisible" 

Answer 4

You created the dialog but not showing it anywhere. Your onPreExecute() should look like:

@Override
protected void onPreExecute() {

    super.onPreExecute();
    // create dialog
    dialog=new Dialog(context);
    dialog.setCancelable(true);
    dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
    dialog.setContentView(R.layout.pogressdialog);
    txtprogrss=(TextView) dialog.findViewById(R.id.txtProgress);
    progress=(ProgressBar)dialog.findViewById(R.id.progressBar2);
    btnCancel=(Button)dialog.findViewById(R.id.btnProgress);

    btnCancel.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub

            MyTask.this.cancel(true);
            dialog.dismiss();  //On button click cancel AsyncTask and dismiss dialog
        }
    });
    dialog.show();  //Show the dialog
}

You also need to dismiss the dialog when clicked on btnCancel.

Answer 5

You forgot to call dialog.show() at the onPreExecute()