Android自定义控件之自定义倒计时按钮

自定义的倒计时按钮应该很多人都做过，我想最常见的实现方式应该就是开启一个子线程，然后通过Handler去更新UI实现，

这里我自定义了一个按钮，通过在handler中发送handler的方式，也同样实现了计时器的效果，而且也不需要开子线程，是代码的内存消耗更小更具有操作性

实现效果如下



直接上代码：

package com.fizzer.doraemon.localdemo.Animation.View;

import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.widget.Button;
import android.widget.Chronometer;

/**
* Created by Fizzer on 2016/12/13.
* Email: doraemonmqq@sina.com
* 倒计时控件
*/

public class CountDownButton extends Button {

private boolean isRunning = false;

private int startTime = 10;

private int changeTime;

private int TASK_RUNNING = 1;

public CountDownButton(Context context) {
super(context);
}

public CountDownButton(Context context, AttributeSet attrs) {
super(context, attrs);
}

public CountDownButton(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}

public void start() {
isRunning = true;
changeTime = startTime;
setText(changeTime + "秒");
updateRunning();
}

public void stop() {
isRunning = false;
updateRunning();
}

/**
* 设置倒计时时间
* @param time time
*/
public void setStartTime(int time) {
this.startTime = time;
}

private void updateRunning() {
if (isRunning) {
mHandler.sendMessageDelayed(Message.obtain(mHandler, TASK_RUNNING), 1000);
} else {
mHandler.removeMessages(TASK_RUNNING);
}
}

Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
changeTime--;
setText(changeTime + "秒");
setClickable(false);
if (changeTime >= 0) {
mHandler.sendMessageDelayed(Message.obtain(mHandler, TASK_RUNNING), 1000);
} else {
changeTime = startTime;
mHandler.removeMessages(TASK_RUNNING);
setText("重新开始");
setClickable(true);
}
}
};

/**
* 界面关闭的时候，停止发送handler
*/
@Override
protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
isRunning = false;
updateRunning();
}
}


在使用的类中调用一下start方法就行了

mMyButton.start();