android 下载应用 通知栏显示进度 下完之后点击安装 （很实用）

先看效果图： 这是本人的习惯，先上图显示效果，看是否是想要的，再看代码。有图有真相

代码：

Main:

package com.gem.hsx.appupdate;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class Main extends Activity {

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		Button btnok=(Button) findViewById(R.id.btnok);
		btnok.setOnClickListener(new BtnokOnClickListener());
	}

	private class BtnokOnClickListener implements OnClickListener 
	{

		@Override
		public void onClick(View v) {
			Intent updateIntent =new Intent(Main.this, UpdateService.class);
			updateIntent.putExtra("titleId",R.string.app_name);
			startService(updateIntent);

		}
	}
}

UpdateService:

package com.gem.hsx.appupdate;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Intent;
import android.net.Uri;
import android.os.Environment;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;

public class UpdateService extends Service{
	//标题
	private int titleId = 0;
	private final static int DOWNLOAD_COMPLETE = 0;
	private final static int DOWNLOAD_FAIL = 1; 
	//文件存储
	private File updateDir = null;
	private File updateFile = null;
	 
	//通知栏
	private NotificationManager updateNotificationManager = null;
	private Notification updateNotification = null;
	//通知栏跳转Intent
	private Intent updateIntent = null;
	private PendingIntent updatePendingIntent = null;
	@Override
	public IBinder onBind(Intent intent) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public void onCreate() {
		
		super.onCreate();
	}

	@Override
	public int onStartCommand(Intent intent, int flags, int startId) {
		//获取传值
	    titleId = intent.getIntExtra("titleId",0);
	    //创建文件
	    if(android.os.Environment.MEDIA_MOUNTED.equals(android.os.Environment.getExternalStorageState())){
	        updateDir = new File(Environment.getExternalStorageDirectory(),"app/download/");
	        updateFile = new File(updateDir.getPath(),getResources().getString(titleId)+".apk");
	    }
	 
	    this.updateNotificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
	    this.updateNotification = new Notification();
	 
	    //设置下载过程中，点击通知栏，回到主界面
	    updateIntent = new Intent(this, Main.class);
	    updatePendingIntent = PendingIntent.getActivity(this,0,updateIntent,0);
	    //设置通知栏显示内容
	    updateNotification.icon = R.drawable.ic_launcher;
	    updateNotification.tickerText = "开始下载";
	    updateNotification.setLatestEventInfo(this,"上海地铁","0%",updatePendingIntent);
	    //发出通知
	    updateNotificationManager.notify(0,updateNotification);
	 
	    //开启一个新的线程下载，如果使用Service同步下载，会导致ANR问题，Service本身也会阻塞
	    new Thread(new updateRunnable()).start();//这个是下载的重点，是下载的过程
	     
	    return super.onStartCommand(intent, flags, startId);
	}
	private Handler updateHandler = new  Handler(){
	    @Override
	    public void handleMessage(Message msg) {
	    	 switch(msg.what){
	            case DOWNLOAD_COMPLETE:
	            	updateNotification.flags|=updateNotification.FLAG_AUTO_CANCEL;
	                //点击安装PendingIntent
	                Uri uri = Uri.fromFile(updateFile);
	                Intent installIntent = new Intent(Intent.ACTION_VIEW);
	                installIntent.setDataAndType(uri, "application/vnd.android.package-archive");
	                updatePendingIntent = PendingIntent.getActivity(UpdateService.this, 0, installIntent, 0);
	                 
	                updateNotification.defaults = Notification.DEFAULT_SOUND;//铃声提醒 
	                updateNotification.setLatestEventInfo(UpdateService.this, "上海地铁", "下载完成,点击安装。", updatePendingIntent);
	                updateNotificationManager.notify(0, updateNotification);
	                 
	                //停止服务
	                stopService(updateIntent);
	            case DOWNLOAD_FAIL:
	                //下载失败
	                updateNotification.setLatestEventInfo(UpdateService.this, "上海地铁", "下载完成,点击安装。", updatePendingIntent);
	                updateNotificationManager.notify(0, updateNotification);
	            default:
	                stopService(updateIntent);
	        }  
	    }
	};
	
	
	class updateRunnable implements Runnable {
        Message message = updateHandler.obtainMessage();
        public void run() {
            message.what = DOWNLOAD_COMPLETE;
            try{
                //增加权限;
                if(!updateDir.exists()){
                    updateDir.mkdirs();
                }
                if(!updateFile.exists()){
                    updateFile.createNewFile();
                }
                //下载函数，以QQ为例子
                //增加权限;
                long downloadSize = downloadUpdateFile("http://softfile.3g.qq.com:8080/msoft/179/1105/10753/MobileQQ1.0(Android)_Build0198.apk",updateFile);
                if(downloadSize>0){
                    //下载成功
                    updateHandler.sendMessage(message);
                }
            }catch(Exception ex){
                ex.printStackTrace();
                message.what = DOWNLOAD_FAIL;
                //下载失败
                updateHandler.sendMessage(message);
            }
        }
    }
	
	
	
	public long downloadUpdateFile(String downloadUrl, File saveFile) throws Exception {
        //这样的下载代码很多，我就不做过多的说明
        int downloadCount = 0;
        int currentSize = 0;
        long totalSize = 0;
        int updateTotalSize = 0;
         
        HttpURLConnection httpConnection = null;
        InputStream is = null;
        FileOutputStream fos = null;
         
        try {
            URL url = new URL(downloadUrl);
            httpConnection = (HttpURLConnection)url.openConnection();
            httpConnection.setRequestProperty("User-Agent", "PacificHttpClient");
            if(currentSize > 0) {
                httpConnection.setRequestProperty("RANGE", "bytes=" + currentSize + "-");
            }
            httpConnection.setConnectTimeout(10000);
            httpConnection.setReadTimeout(20000);
            updateTotalSize = httpConnection.getContentLength();
            if (httpConnection.getResponseCode() == 404) {
                throw new Exception("fail!");
            }
            is = httpConnection.getInputStream();                   
            fos = new FileOutputStream(saveFile, false);
            byte buffer[] = new byte[4096];
            int readsize = 0;
            while((readsize = is.read(buffer)) > 0){
                fos.write(buffer, 0, readsize);
                totalSize += readsize;
                //为了防止频繁的通知导致应用吃紧，百分比增加10才通知一次
                if((downloadCount == 0)||(int) (totalSize*100/updateTotalSize)-10>downloadCount){ 
                    downloadCount += 10;
                    updateNotification.setLatestEventInfo(UpdateService.this, "正在下载", (int)totalSize*100/updateTotalSize+"%", updatePendingIntent);
                    updateNotificationManager.notify(0, updateNotification);
                }                        
            }
        } finally {
            if(httpConnection != null) {
                httpConnection.disconnect();
            }
            if(is != null) {
                is.close();
            }
            if(fos != null) {
                fos.close();
            }
        }
        return totalSize;
    }
		
}

AndroidManifest.xml