获取验证码的按钮，实时更新

private long remainTime=60000;
private long mSecondRemailTime;
public static CountDownTimer mCountDownTimer;               
if (remainTime == 60000l) {
                   mSecondRemailTime = remainTime;
                   if (mCountDownTimer != null) {
                       mCountDownTimer.cancel();
                   }
                   mCountDownTimer = new CountDownTimer(mSecondRemailTime,
                           1000) {
                       public void (long millisUntilFinished) {
                           btnSendAuthCode.setClickable(false);
                           btnSendAuthCode.setText(millisUntilFinished / 1000
                                   + "后获取");
                           remainTime = millisUntilFinished;
                       }

                       public void onFinish() {
                           btnSendAuthCode.setClickable(true);
                           btnSendAuthCode.setText("获取验证码");
                           remainTime = 60000l;
                       }
                   };
                   mCountDownTimer.start();
               }