如何实现ProgresDialog [Android]

public void onCreate(Bundle savedInstanceState) {
    MyDialog = ProgressDialog.show(this, \"Nalagam kanale\" , \"Prosimo počakaj ... \", true);
    MyDialog.show();
... }

package com.TVSpored;

import java.util.ArrayList;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListView;


public class Currently extends Activity{
static final int PROGRESS_DIALOG = 0;

private ArrayList<CurrentlyItem> currentItems;

private CurrentAdapter aa;
private ListView currentListView;

private JSONArray CurrentShows;
private Communicator CommunicatorEPG;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle icicle) {
    super.onCreate(icicle);     
    setContentView(R.layout.layout_currently);


    CommunicatorEPG = new Communicator();
    currentItems = new ArrayList<CurrentlyItem>();

    if(currentItems == null)

    int resID = R.layout.current_item;
    aa = new CurrentAdapter(this, resID, currentItems);


    currentListView = (ListView)findViewById(R.id.currentListView);

    try {
        currentListView.setAdapter(aa);
    } catch (Exception e) {
        Log.d(\" * Napaka\", e.toString());
    }


    try {
        populateCurrent();
    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}
public void populateCurrent() throws JSONException
{
    CurrentShows = CommunicatorEPG.getCurrentShows(0);

    for (int i = 0; i < CurrentShows.length(); i++) 
    {
        JSONObject jsonObject = CurrentShows.getJSONObject(i);

          String start = jsonObject.getString(\"1\");
          Integer duration = jsonObject.getInt(\"2\");
          String title = jsonObject.getString(\"3\");
          String epg_channel = jsonObject.getString(\"4\");
          String channel_name = jsonObject.getString(\"5\");
          CurrentlyItem newItem = new CurrentlyItem(1, 2, 3, 4, 5);
          currentItems.add(i, newItem);
    }
}
}

AsyncTask

populateCurrent();

JSONArray