Android利用CountDownTimer实现点击获取验证码倒计时效果

package com.loaderman.countdowntimerdemo; import android.os.Bundle;import android.os.CountDownTimer;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.TextView; public class MainActivity extends AppCompatActivity {   private TextView tvTime;   @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    tvTime = (TextView) findViewById(R.id.tv_time);    tvTime.setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        new countDownTimer<TextView>(tvTime);      }    });  }  public class countDownTimer<T> extends CountDownTimer {    private TextView mTextView;     public countDownTimer(T text) {      super(60000,1000);      this.mTextView = ((TextView)text);      mTextView.setClickable(false);      start();    }     /**     * start后开始执行的方法，按照间隔时间执行一次     * @param millisUntilFinished     */    @Override    public void onTick(long millisUntilFinished) {      mTextView.setText(String.format("%s秒",millisUntilFinished/1000));    }     /**     * 时间结束时调用的方法     */    @Override    public void onFinish() {      mTextView.setText("获取验证码");      mTextView.setClickable(true);    }  }}

<?xml version="1.0" encoding="utf-8"?><RelativeLayout  xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:id="@+id/activity_main"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:gravity="center"  tools:context="com.loaderman.countdowntimerdemo.MainActivity">  <TextView    android:textColor="#F00"    android:textSize="18sp"    android:id="@+id/tv_time"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="开始倒计时"/></RelativeLayout>