Android中Timer施用示例

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);
??? }
}