#pragma mark 获取验证码倒计时
-(void)countDown{i
_secondsCountDown=60;
[_captchaBtn setHighlighted:NO];
_countDownTimer=[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(updateCodeBtn) userInfo:nil repeats:YES];
}
-(void)updateCodeBtn {
if(_secondsCountDown>=0){
//重要的是这一句 设置Button 的titleLabel text属性
_captchaBtn.titleLabel.text = [NSString stringWithFormat:@"%ds",_secondsCountDown];
//并且title也要设置
[_captchaBtn setTitle:[NSString stringWithFormat:@"%ds",_secondsCountDown]forState:UIControlStateNormal];
_secondsCountDown--;
}else{
[_captchaBtn setTitle:@"获取验证码" forState:UIControlStateNormal];
_countDownTimer=nil;
[_captchaBtn setEnabled:YES];
}
}
