iOS短信倒计时验证码

直接上代码

__blockinttimeout=60;//倒计时时间

    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

    dispatch_source_t _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,queue);

    dispatch_source_set_timer(_timer,dispatch_walltime(NULL, 0),1.0*NSEC_PER_SEC, 0); //每秒执行

    dispatch_source_set_event_handler(_timer, ^{

        if(timeout<=0){//倒计时结束，关闭

            dispatch_source_cancel(_timer);

            dispatch_async(dispatch_get_main_queue(), ^{

      //可以根据自己的实际界面图进行更改

                [self.SendMsgBtnsetTitle:@"发送验证码"forState:UIControlStateNormal];

                self.SendMsgBtn.userInteractionEnabled = YES;

            });

        }else{

            intseconds = timeout %61;

            NSString*strTime = [NSStringstringWithFormat:@"%.2d", seconds];

            dispatch_async(dispatch_get_main_queue(), ^{

                [UIView beginAnimations:nil context:nil];

                [UIView setAnimationDuration:1];

                [self.SendMsgBtn setTitle:[NSString stringWithFormat:@"%@S",strTime] forState:UIControlStateNormal];

                [UIView commitAnimations];

                self.SendMsgBtn.userInteractionEnabled = NO;

            });

            timeout--;

        }

    });

    dispatch_resume(_timer);