ios 倒计时

倒计时总是要上网去找 直接放个笔记在这得了

新建UIbutton子类,然后用这个button就好了

.m中

#define SendCode @"发送验证码"

@interface PEMCodeButton()

{

    dispatch_source_t _timer;

}

@end

@implementation PEMCodeButton

- (void) startSend

{

    [self openCountdown:NO];

}

- (void)endSending

{

    dispatch_source_cancel(_timer);

    dispatch_async(dispatch_get_main_queue(), ^{

        //设置按钮的样式

        [self setTitle:SendCode forState:UIControlStateNormal];

        self.userInteractionEnabled = YES;

    });

}

// 开启倒计时效果

-(void)openCountdown:(BOOL) isFail{

    __blockNSIntegertime =59;//倒计时时间

    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

    _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(time <=0|| isFail){//倒计时结束，关闭

            dispatch_source_cancel(_timer);

            dispatch_async(dispatch_get_main_queue(), ^{

                //设置按钮的样式

                [self setTitle:SendCode forState:UIControlStateNormal];

                self.userInteractionEnabled = YES;

            });

        }else{

            intseconds = time %60;

            dispatch_async(dispatch_get_main_queue(), ^{

                //设置按钮显示读秒效果

                [self setTitle:[NSString stringWithFormat:@"重新发送(%.2d)", seconds] forState:UIControlStateNormal];

                self.userInteractionEnabled = NO;

            });

            time--;

        }

    });

    dispatch_resume(_timer);

}

.h中

- (void) startSend;//开始倒计时

- (void)endSending;//请求服务器失败关闭倒计时