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);
    }
}