Android使用CountDownTimer模拟短信验证倒计时

<?xml version="1.0" encoding="utf-8"? 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context="com.example.leixiansheng.countdowntimer.MainActivity" 
 
 <TextView
  android:id="@+id/tv_getMsg"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_centerInParent="true"
  android:text="获取短信验证码"
  android:background="@color/colorPrimaryDark"
  android:textSize="16sp"
  android:textColor="#ffffffff" / 
</RelativeLayout 

package com.example.leixiansheng.countdowntimer;
 
import android.os.CountDownTimer;
import android.widget.TextView;
 
/**
 * Created by Leixiansheng on 2018/7/18.
 */
 
public class TimerCount extends CountDownTimer {
 
 private TextView mTextView;
 
 
 public TimerCount(long millisInFuture, long countDownInterval, TextView textView) {
 super(millisInFuture, countDownInterval);
 mTextView = textView;
 }
 
 @Override
 public void onTick(long millisUntilFinished) {
 mTextView.setClickable(false);
 mTextView.setText("重新获取" + millisUntilFinished / 1000 + "秒");
 }
 
 @Override
 public void onFinish() {
 mTextView.setClickable(true);
 mTextView.setText("获取短信验证码");
 }
}

package com.example.leixiansheng.countdowntimer;
 
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
 
public class MainActivity extends AppCompatActivity {
 
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 
 final TextView textView = (TextView) findViewById(R.id.tv_getMsg);
 textView.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
 /**
  * millisInFuture:要计数的总时长
  * countDownInterval:每隔多少秒响应
  */
 TimerCount timerCount = new TimerCount(5000, 1000, textView);
 timerCount.start();
 }
 });
 }
}