Android Timer的用法示例

写惯java的人可能会认为Timer的使用应该如下：

程序功能很简单：10秒后，SetTitle为“hear me?”，然后，实际上这样做是不行的，这跟Android的线程安全有关！

package com.ray.test;

import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.os.Bundle;

public class JavaTimer extends Activity {

	Timer timer = new Timer();
	TimerTask task = new TimerTask(){

		public void run() {
	        setTitle("hear me?");
		}
		
	};
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        timer.schedule(task, 10000);
    }
}

 

但实际上的用法应该通过配合Handler来实现timer功能的！

package com.ray.test;

import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;

public class TestTimer extends Activity {

	Timer timer = new Timer();
	Handler handler = new Handler(){

		public void handleMessage(Message msg) {
			switch (msg.what) {    
			case 1:    
				setTitle("hear me?");
				break;    
			}    
			super.handleMessage(msg);
		}
		
	};
	TimerTask task = new TimerTask(){

		public void run() {
			Message message = new Message();    
			message.what = 1;    
			handler.sendMessage(message);  
		}
		
	};
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        timer.schedule(task, 10000);
    }
}