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>