public class MyAsyncTaskClass extends AsyncTask {
	private ProgressDialog referenceToDialogFromAnotherClass;

	public MyAsyncTaskClass(ProgressDialog dialogFromAnotherClass) {
		this.referenceToDialogFromAnotherClass = dialogeFromAnotherClass;
	}

	@Override
	public void onPostExecute() {
		this.referenceToDialogFromAnotherClass.show();
		// Do other stuff with the dialog like setting a title or text or something.
	}

	@Override
	public void doInBackground(args...) {
		// Do stuff in the background here.
	}

	@Override
	public void onPreExecute() {
		// We're done, so let's remove the dialog again.
		this.referenceToDialogFromAnotherClass.dismiss();
	}
}