Handler and Thread

package gt.gt;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.pm.ApplicationInfo;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.widget.ListView;
import android.widget.SimpleAdapter;

public class SoftWare extends Activity implements Runnable {
   
 List<Map<String,Object>> list=null;
    ListView itemlist=null;
    private ProgressDialog pd;
   
   

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.infos);
  setTitle("软件信息");
  itemlist=(ListView)findViewById(R.id.itemlist);
  pd=ProgressDialog.show(this, "请稍后","正在收集软件信息。。。",true,false);
  Thread thread=new Thread(this);
  thread.start();
 }

 

 @Override
 public void run() {
  fetch_installed_apps();
          handler.sendEmptyMessage(0);

 }

 
 private Handler handler=new Handler(){
  public void handleMessage(Message msg){
        refreshListItems();
  pd.dismiss();
  }
 };
 public List fetch_installed_apps(){
  List<ApplicationInfo> packages=getPackageManager().getInstalledApplications(0);
  list=new ArrayList<Map<String,Object>>(1);
  Iterator<ApplicationInfo> l = packages.iterator();
  while(l.hasNext()){
   Map<String,Object>map =new HashMap<String,Object>();
   ApplicationInfo app=(ApplicationInfo)l.next();
   String packageName=app.packageName;
   String label="";
   try{
    label=getPackageManager().getApplicationLabel(app).toString();
   }
   catch(Exception e)
   {
   Log.i("Exception",e.toString());
   }
   map=new HashMap<String,Object>();
   map.put("name", label);
   map.put("desc", packageName);
   list.add(map);
  }
  return list;
 }
 
 private void refreshListItems(){
  list=fetch_installed_apps();
  SimpleAdapter notes=new SimpleAdapter(this,list,R.layout.info_row
    ,new String[]{"name","desc"},new int[]{R.id.name,R.id.desc});
  itemlist.setAdapter(notes);
  setTitle("软件信息,已经安装"+list.size()+"款应用");
 }
 
}