///// 第一步：获取NotificationManager
  NotificationManager nm = (NotificationManager) 
    getSystemService(Context.NOTIFICATION_SERVICE);

  ///// 第二步：定义Notification
  Intent intent = new Intent(this, OtherActivity.class);
  //PendingIntent是待执行的Intent
  PendingIntent pi = PendingIntent.getActivity(this, 0, intent,
    PendingIntent.FLAG_CANCEL_CURRENT);
  Notification notification = new Notification.Builder(this)
    .setContentTitle("title")
    .setContentText("text")
    .setSmallIcon(R.drawable.ic_launcher).setContentIntent(pi)
    .build();
  notification.flags = Notification.FLAG_NO_CLEAR;
  
  /////第三步：启动通知栏，第一个参数是一个通知的唯一标识
  nm.notify(0, notification);
  
  //关闭通知
  //nm.cancel(0);