android 定时器实现

ontimer.java

//一、采用Handle与线程的sleep(long)方法
class Timer1{

  //1. 定义一个Handler类，用于处理接受到的Message。
  Handler handler = new Handler() {
      public void handleMessage(Message msg) {
          // 要做的事情
          super.handleMessage(msg);
      }
  };
  
  //2. 新建一个实现Runnable接口的线程类，如下：
  public class MyThread implements Runnable {
  	@Override
  	public void run() {
  		// TODO Auto-generated method stub
  		while (true) {
  			try {
  				Thread.sleep(10000);// 线程暂停10秒，单位毫秒
  				Message message = new Message();
  				message.what = 1;
  				handler.sendMessage(message);// 发送消息
  			} catch (InterruptedException e) {
  				// TODO Auto-generated catch block
  				e.printStackTrace();
  			}
  		}
  	}
  }
  
  //3. 在需要启动线程的地方加入下面语句：
  public void test(){
    new Thread(new MyThread()).start();
  }
}

//二、采用Handler的postDelayed(Runnable, long)方法
class Timer2{
  //1. 定义一个Handler类
  public void test(){
    Handler handler=new Handler();
    Runnable runnable=new Runnable() {
        @Override
        public void run() {
            // TODO Auto-generated method stub
            //要做的事情
            handler.postDelayed(this, 2000);
        }
    };
    //2. 启动计时器
    handler.postDelayed(runnable, 2000);//每两秒执行一次runnable. 
    //3. 停止计时器
    handler.removeCallbacks(runnable);  
  }
}

//三、采用Handler与timer及TimerTask结合的方法
class Timer3{

  public void test(){
    //1. 定义定时器、定时器任务及Handler句柄
    private final Timer timer = new Timer(); 
    private TimerTask task; 
    Handler handler = new Handler() { 
        @Override 
        public void handleMessage(Message msg) { 
            // TODO Auto-generated method stub 
            // 要做的事情 
            super.handleMessage(msg); 
        }
    };
    //2. 初始化计时器任务
    task = new TimerTask() { 
        @Override 
        public void run() { 
            // TODO Auto-generated method stub 
            Message message = new Message(); 
            message.what = 1; 
            handler.sendMessage(message); 
        } 
    }; 
    //3. 启动定时器
    timer.schedule(task, 2000, 2000); 
  }
  
}