Notification探险

多任务机制下,程序跑在后台,用户使用服务,形成了一个良好的使用结构。程序运行的状态或结果,在不干扰用户当前使用的状态下,以通知的方式通知用户,能大大提升地用户的使用感。

 

在android下,与通知功能相关的组件大致有以下三大部分:

 

android.app.PendingIntent;
android.app.NotificationManager; 
android.app.Notification;

NotificationManager可以通过系统的服务获取,我就是通过它向用户发出通知的

notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

 

Notification,通知的主体,通过设置其各种属性,来实现通知的效果,

 

PendingIntent,Intent的封装类,主要是用来导向点击通知后要启动的Activity。不过这里主要牵涉到Intent属性的设置,以下两段代码,前者跳转Activity时会新建一个Activity的实例,后者则会先从栈堆里弹出

 

intent = new Intent(NotificationTest.this, NotificationTest.class);
		intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | 
				Intent.FLAG_ACTIVITY_CLEAR_TOP);
		pendIntent = PendingIntent.getActivity(NotificationTest.this, 0, intent, 0);
		notif.contentIntent = pendIntent;

 

		intent = new Intent(Intent.ACTION_MAIN);
		intent.addCategory(Intent.CATEGORY_LAUNCHER);
		intent.setClass(NotificationTest.this, NotificationTest.class);
		intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | 
				Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
		pendIntent = PendingIntent.getActivity(NotificationTest.this, 0, intent, 0);

 android下的通知组件使用起来很简单,下面是自己的一个例子,例子模拟下载的通知,并使用Timer和Handle一步更新通知上的进度条:

public class NotificationTest extends Activity {

	private NotificationManager notificationManager;
	private String svcName = Context.NOTIFICATION_SERVICE;
	private Intent intent;
	private PendingIntent pendIntent;
	private Notification notif; //通知的变量
	private RemoteViews rv = null; //自定义通知的外观
	private final int NOFI_REF = 1; //通知的标志
	private TextView tv = null;
	private Timer timer = null;
	private int number = 0;
	private int num = 0;
	private boolean isOver = true;

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		tv = (TextView) findViewById(R.id.myTv);
		tv.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View arg0) {
				if(number!=0){
					tv.setText("down again! \n");
				}
				if (timer == null && isOver==true) {
					setNotification();
					timer = new Timer();
					timer.schedule(new MyTask(), 1000);
					isOver = false;
				} 
			}

		});
		tv.setText("Tis is Notification Test! \n Click screen to start! \n");
        //获取系统的通知服务管理器实例
		notificationManager = (NotificationManager) getSystemService(svcName);

	}

	private void setNotification() {
		long when = System.currentTimeMillis();
		notif = new Notification(android.R.drawable.ic_media_rew,
				"Test Notification", when);  //new一个通知的实例,并设置在状态栏的显示方式
		// 点击通知时转移的内容
		intent = new Intent(Intent.ACTION_MAIN);
		intent.addCategory(Intent.CATEGORY_LAUNCHER);
		intent.setClass(NotificationTest.this, NotificationTest.class);
		//设置intent的标志,以控制目标Activity的启动方式
		intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | 
				Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
		pendIntent = PendingIntent.getActivity(NotificationTest.this, 0, intent, 0);
		notif.contentIntent = pendIntent;  //
		
		//notif.defaults = Notification.DEFAULT_SOUND; //设置通知的声音,也可以通过uri属性自定义
		
		long[] ss = {1000,500,1000};
		notif.vibrate = ss; //设置通知时震动
		
		rv = new RemoteViews(this.getPackageName(), 
				R.layout.my_notification_view);  //设置通知自定义的外观
		notif.contentView = rv; //
		//设置进度条的最大进度和初始进度
		notif.contentView.setProgressBar(R.id.pb, 100, 10, false);
        //显示下载的内容
		notif.contentView.setTextViewText(R.id.tv_name, "正在下载");
        //显示下载的进度
		notif.contentView.setTextViewText(R.id.tv_p, "0%");
		notif.flags = Notification.FLAG_ONGOING_EVENT; //设置通知的标志,定义在通知栏上的显示方式
		notificationManager.notify(NOFI_REF, notif); //向系统发出通知
	}

	class MyTask extends TimerTask {

		@Override
		public void run() {
			Message msg = new Message();
			num+=5;
			Bundle b = new Bundle();
			b.putInt("pb", num);
			msg.setData(b);
			msg.what = 1;
			handeler.sendMessage(msg);
		}
	};
	
	private Handler handeler = new Handler(){
		public void handleMessage(Message msg) {  
			if(msg.what==1){
				Bundle b =msg.getData();
				int i = b.getInt("pb");
				if(i<100){
					tv.setText(tv.getText() + "Notification update:" + i + "\n");
					timer.cancel();
					timer = null;
					if(i%10==0){
						rv.setProgressBar(R.id.pb, 100, i, false); //更新进度条
						rv.setTextViewText(R.id.tv_p, i+"%"); //更新label的值
						notif.vibrate = null; //关掉震动
						notif.defaults = 0; //关掉声音
						notificationManager.notify(NOFI_REF, notif); //发出通知,更新通知栏上的状态
					}
					timer = new Timer();
					timer.schedule(new MyTask(), 500);
				} else {
					timer.cancel();
					timer = null;
					//notif.contentView.removeAllViews(R.id.progress_lay);  //去掉进度条
					//notif.contentView.setTextViewText(R.id.tv_name, "下载完成");  //更新显示的信息
					
					notif.setLatestEventInfo(NotificationTest.this,
							"下载完成", "OK!", pendIntent); //如方法名称一样,设置要通知的最新事件信息
					//要注意的是,绑定通知的contentView和通知的setLatestEventInfo方法,
					//两者只能选一种,否则通知只会展现最后绑定的效果
					
					notif.flags = Notification.FLAG_AUTO_CANCEL; //设置通知在用户点击后就会自动取消
					long[] ss = {1000,500,1000};
					notif.vibrate = ss;
					notif.number = ++number; //设置通知的条数 
					notificationManager.notify(NOFI_REF, notif); //发出通知,更新通知栏上的状态
					
					isOver = true;
					num = 0;
				}
			}
			
		}
	};
}

 

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