Android中Timer使用示例

Android中Timer使用示例

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);

}

}