带进度条的通知栏

有时候会有些业务需要后台运行并以通知的形式，比如升级，监控什么的。
这里说下我的业务，通过提示用户升级，然后点击升级开启一个service服务在
后台进行下载并以通知的形式提供用户查看，下载完成点击通知进入安装。

1.开启服务

 

Intent intent = new Intent();
intent.setClass(mContext, UpgradeService.class);
startService(intent);

 

2.建立一个服务servive类
在onStart方法中建立notification,做写准备工作.

@Override
 public void onStart(Intent intent, int startId) {
  String sdPath = FileHelper.getSDCardPath();
  if (sdPath != null) {
   updateFile = new File(sdPath + Global.downloadDir + "petfone.apk");
   // 初始化通知管理器
   this.updateNotificationMgr = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
   this.updateNotification = new Notification();
   updateNotification.icon=R.drawable.ic_launcher;
   updateIntent = new Intent(this, UpdateAppDemoActivity.class);
   updatePendingIntent = PendingIntent.getActivity(this, 0,updateIntent, 0);
   //通知自定义视图
   updateNotification.contentView = new RemoteViews(getPackageName(),com.hua.test.R.layout.mynotification_progressbar);
   updateNotification.contentView.setProgressBar(com.hua.test.R.id.pb_notifi, 100, 0, false);
   updateNotification.contentIntent = updatePendingIntent;//这个pengdingIntent很重要，必须要设置

   // 发出通知
   //updateNotificationMgr.notify(notificationId, updateNotification);

   // 开启线程进行下载
   new Thread(new updateThread()).start();
  }
  super.onStart(intent, startId);
 }
 
3.开启一个线程来下载防止主线程堵塞。这里在servce写了一个内部类实现了Runnable
 class updateThread implements Runnable {
  Message msg = handler.obtainMessage();
  @Override
  public void run() {
   try {
    if (!updateFile.exists()) {
     updateFile.createNewFile();
    }
    long downSize = downloadFile(Global.NET_ADDRESS+"PetFone_G_Google.apk",updateFile);
    if(downSize>0){
     //下载成功！
     msg.what=DOWNLOAD_SUCCESS;
     handler.sendMessage(msg);
    } 
   } catch (Exception ex) {
    ex.printStackTrace();//下载失败
    msg.what=DOWNLOAD_FALL;
    handler.sendMessage(msg);
   }
  }
 }
 
 /**
  * 下载文件
  * @param downloadUrl 下载路径
  * @param saveFile 保存文件名
  */
 public long downloadFile(String downloadUrl, File saveFile) throws Exception {
    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();//总大小
     if(httpConnection.getResponseCode()==404){
      throw new Exception("conection net 404！");
     }
     is = httpConnection.getInputStream();
     fos = new FileOutputStream(saveFile);
     byte[] buf = new byte[1024];
     int readSize = -1;
    
     while((readSize = is.read(buf)) != -1){
      fos.write(buf, 0, readSize);
      //通知更新进度
      totalSize += readSize;
      int tmp = (int) (totalSize * 100 / updateTotalSize);
    //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 || tmp-10>downloadCount){
       downloadCount+=10;
       Message msg = handler.obtainMessage();
       msg.what=DOWNLOAD_COMPLETE;
       msg.arg1=downloadCount;
       handler.sendMessage(msg);
      }
     }
    }catch(Exception ex){
     ex.printStackTrace();
    }finally{
      if(httpConnection != null) {                    
        httpConnection.disconnect();    
       }               
      if(is != null) {  
            is.close();  
       }                
        if(fos != null) { 
         fos.close(); 
      }
    }
  return totalSize;
 }

 

 
4.需要不段的给progressBar 提供值，所以要使用handler,下载文件一定也就有3种状态，
1）.下载中，2）.下载失败，3）.下载成功。
在servive中定义好handler并定义这个3个状态码。
private final int DOWNLOAD_COMPLETE = 1, DOWNLOAD_FALL=2,DOWNLOAD_SUCCESS=3;
然后在处理这个message

private Handler handler = new Handler() {
  @Override
  public void handleMessage(Message msg) {
   super.handleMessage(msg);
   switch(msg.what){
   case DOWNLOAD_SUCCESS:
    //下载完成点击通知进入安装
    Uri uri = Uri.fromFile(updateFile); 
    Intent installIntent = new Intent(Intent.ACTION_VIEW); 
    installIntent.setDataAndType(uri, "application/vnd.android.package-archive"); 
    updatePendingIntent = PendingIntent.getActivity(UpgradeService.this, 0, installIntent, 0);  
    updateNotification.defaults = Notification.DEFAULT_SOUND;//设置铃声
    updateNotification.contentIntent = updatePendingIntent;
    //更新通知视图值
    updateNotification.contentView.setTextViewText(com.hua.test.R.id.tv_downInfo, "下载成功,点击安装。");
    updateNotification.contentView.setProgressBar(com.hua.test.R.id.pb_notifi, 100, 100, false);
     updateNotificationMgr.notify(notificationId, updateNotification);
     stopService(updateIntent);//停止service
    break;
   case DOWNLOAD_COMPLETE://下载中状态
    System.out.println(msg.arg1);
    updateNotification.contentView.setProgressBar(com.hua.test.R.id.pb_notifi, 100, msg.arg1, false);
    updateNotification.contentView.setTextViewText(R.id.tv_downInfo, "下载中"+msg.arg1+"%");
    updateNotificationMgr.notify(notificationId, updateNotification);
    break;
   case DOWNLOAD_FALL://失败状态
     //updateNotification.setLatestEventInfo(UpgradeService.this, "下载失败", "", updatePendingIntent);]
     updateNotification.contentView.setTextViewText(com.hua.test.R.id.tv_downInfo, "下载失败");
     updateNotificationMgr.notify(notificationId, updateNotification);
     stopService(updateIntent);//停止service
    break;
   default:
    stopService(updateIntent);
   }
  }
 };