Android中Timer使用示例

android中Timer使用示例

寫慣Java的人可能會認為Timer的使用應該如下：

程序功能很簡單：10秒後，SetTitle為“hear me?”，然後，實際上這樣做是不行的，這跟android的線程安全有關!

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);

}

}

但實際上的用法應該通過配合Handler來實現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);

}

}