Android定时器的使用,

今天在做Android手机屏幕加锁的功能时，即只有解锁才能进入我的手机，没有解锁是不能进入手机，我做了一个定时器定时去唤醒我的解锁界面，下面是demo

package com.gfive.test;

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

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class TimerDemo extends Activity {
/** Called when the activity is first created. */
private Button mButton;
private TextView tv;
private final int UPDATE_TEXT = 1;
private Timer mTimer;
private TimerTask mTimerTask;
private Handler mHandler;
private int i = 0;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

tv = (TextView) findViewById(R.id.tvShow);
mButton = (Button) findViewById(R.id.btn_time);
mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case UPDATE_TEXT:
Calendar calendar = Calendar.getInstance();
mButton.setText("CurrentTime" + calendar.getTime());
tv.setText("数据:"+i++);
if(i > 10){
TimerDemo.this.startActivity(new Intent(TimerDemo.this,TimerDemo.class));
}
break;
default:
break;
}
}
};
mTimer = new Timer();
mTimerTask = new TimerTask() {
@Override
public void run() {
mHandler.sendEmptyMessage(UPDATE_TEXT);
}
};
mTimer.schedule(mTimerTask, 0, 1000);
}
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.gfive.test"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="8" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:label="@string/app_name"
android:name=".TimerDemo"
android:launchMode="singleTask">
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>