Handler线程间通信

  1 package com.hixin.appexplorer;
  2 
  3 import java.util.List;
  4 
  5 import android.app.Activity;
  6 import android.app.ProgressDialog;
  7 import android.content.Context;
  8 import android.content.pm.PackageInfo;
  9 import android.content.pm.PackageManager;
 10 import android.os.Bundle;
 11 import android.os.Handler;
 12 import android.os.Message;
 13 import android.view.LayoutInflater;
 14 import android.view.View;
 15 import android.view.ViewGroup;
 16 import android.view.Window;
 17 import android.view.WindowManager;
 18 import android.widget.BaseAdapter;
 19 import android.widget.GridView;
 20 import android.widget.ImageView;
 21 import android.widget.TextView;
 22 
 23 public class MainActivity extends Activity implements Runnable {
 24 
 25     GridView gv;
 26     private List<PackageInfo> packageInfos;
 27     private ProgressDialog pd;
 28     private Handler mHandler = new Handler() {
 29         @Override
 30         public void handleMessage(Message msg) {
 31             // TODO Auto-generated method stub
 32             super.handleMessage(msg);
 33             gv.setAdapter(new GridViewAdapter(MainActivity.this));
 34             pd.dismiss();
 35             setProgressBarIndeterminateVisibility(false);
 36         }
 37         
 38     };
 39     @Override
 40     protected void onCreate(Bundle savedInstanceState) {
 41         super.onCreate(savedInstanceState);
 42     //    requestWindowFeature(Window.FEATURE_NO_TITLE);
 43         requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
 44         getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
 45         setContentView(R.layout.show_app_grid);
 46         
 47         gv = (GridView)this.findViewById(R.id.gv_apps);
 48         pd = ProgressDialog.show(this,"请稍候...", "正在搜索你所安装的应用程序",true,false);
 49         setProgressBarIndeterminateVisibility(true);
 50         Thread t = new Thread(this);
 51         t.start();
 52         }
 53     
 54     @Override
 55     public void run() {
 56         // TODO Auto-generated method stub
 57         packageInfos = getPackageManager().getInstalledPackages(PackageManager.GET_UNINSTALLED_PACKAGES);
 58         try {
 59             Thread.sleep(2000);
 60         } catch (InterruptedException e) {
 61             // TODO Auto-generated catch block
 62             e.printStackTrace();
 63         }
 64         mHandler.sendEmptyMessage(0);
 65     }
 66     
 67     
 68     class GridViewAdapter extends BaseAdapter{
 69 
 70         LayoutInflater inflater;
 71         public GridViewAdapter(Context context) {
 72             inflater = LayoutInflater.from(context);
 73         }
 74         @Override
 75         public int getCount() {
 76             // TODO Auto-generated method stub
 77             return packageInfos.size();
 78         }
 79 
 80         @Override
 81         public Object getItem(int position) {
 82             // TODO Auto-generated method stub
 83             return packageInfos.get(position);
 84         }
 85 
 86         @Override
 87         public long getItemId(int position) {
 88             // TODO Auto-generated method stub
 89             return position;
 90         }
 91 
 92         @Override
 93         public View getView(int position, View convertView, ViewGroup parent) {
 94             // TODO Auto-generated method stub
 95         
 96                 View view = inflater.inflate(R.layout.gv_item, null);
 97                 TextView tv = (TextView)view.findViewById(R.id.gv_item_appname);
 98                 ImageView iv = (ImageView)view.findViewById(R.id.gv_item_icon);
 99                 tv.setText(packageInfos.get(position).applicationInfo.loadLabel(getPackageManager()));
100                 iv.setImageDrawable(packageInfos.get(position).applicationInfo.loadIcon(getPackageManager()));
101             
102             return view;
103         }
104         
105     }
106     
107 }
108 
109