本文通过CountDownTimer来实现倒计时的功能，先上效果图

效果图.gif

1.核心方法就是通过onTick方法来获取时间的改变

    public void onTick(long millisUntilFinished) {
        //计时过程显示
        this.millisUntilFinished = millisUntilFinished;
        button.setTextColor(Color.parseColor("#FFFFFF"));
        button.setClickable(false);
        button.setTextSize((float) 11.5);
        DecimalFormat dec = new DecimalFormat("##.##");
        button.setText("0" + (int) Math.floor(millisUntilFinished / 60000) + ":" + dec.format((millisUntilFinished % 60000) / 1000) + "s");
    }

其中Math.floor(millisUntilFinished / 60000)是通过毫秒数获取分钟，
dec.format((millisUntilFinished % 60000) / 1000)是对当前毫秒数取余获取出去分钟后的秒数，保留2位

以下是完整代码

package com.shangshaban.zhaopin.utils;

import android.graphics.Color;
import android.os.CountDownTimer;
import android.widget.TextView;

import java.text.DecimalFormat;

/**
 * 作者： 宋正朋 on 2016/6/18.
 * 发送验证码后的倒计时
 */
public class PeterTimeCountRefresh extends CountDownTimer {

    private TextView button;
    private long millisUntilFinished;

    public PeterTimeCountRefresh(long millisInFuture, long countDownInterval, final TextView button) {
        super(millisInFuture, countDownInterval);//参数依次为总时长,和计时的时间间隔,要显示的按钮
        this.button = button;
    }

    @Override
    public void onTick(long millisUntilFinished) {//计时过程显示
        this.millisUntilFinished = millisUntilFinished;
        button.setTextColor(Color.parseColor("#FFFFFF"));
        //button.setBackgroundResource(R.drawable.send_code_wait);
        button.setClickable(false);
        button.setTextSize((float) 11.5);
        DecimalFormat dec = new DecimalFormat("##.##");
        button.setText("0" + (int) Math.floor(millisUntilFinished / 60000) + ":" + dec.format((millisUntilFinished % 60000) / 1000) + "s");
    }

    @Override
    public void onFinish() {//计时完毕时触发
        button.setText("刷新");
        button.setTextColor(Color.parseColor("#FFFFFF"));
        // button.setBackgroundResource(R.drawable.send_code);
        button.setClickable(true);
    }

}

2.在Activity中的使用

PeterTimeCountRefresh timer = new PeterTimeCountRefresh(600000, 1000, btnRefresh);
timer.start();

3.最后，在onDestroy中关掉计时器，防止内存泄漏

@Override
    protected void onDestroy() {
        super.onDestroy();
        if (timer != null) {
            timer.cancel();
        }
    }

OK，搞定！