GCD实现计时器

最新推荐文章于 2020-12-19 16:51:57 发布

bigjar_W

最新推荐文章于 2020-12-19 16:51:57 发布

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分类专栏： iOS 文章标签： iOS 计时器 GCD

本文链接：https://blog.youkuaiyun.com/zju_bigjar/article/details/51312511

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 UIButton *button = (UIButton *)[self viewWithTag:999];
            __block int timeout = 60;
            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);
            dispatch_source_set_event_handler(_timer, ^{
                if (timeout <= 0) {
                    dispatch_source_cancel(_timer);
                    dispatch_async(dispatch_get_main_queue(), ^{
                        [button setTitle:@"获取短信" forState:UIControlStateNormal];
                        button.enabled = YES;
                        [button setTitleColor:[UIColor colorWithRed:20/255.0 green:130/255.0 blue:190/255.0 alpha:1.0] forState:UIControlStateNormal];
                    });
                } else {
                    int seconds = timeout;
                    NSString *strTime = [NSString stringWithFormat:@"%.2d",seconds];
                    dispatch_async(dispatch_get_main_queue(), ^{
                        button.enabled = NO;
                        [button setTitle:[NSString stringWithFormat:@"%@秒后获取",strTime] forState:UIControlStateDisabled];
                        [button setTitleColor:[UIColor lightGrayColor] forState:UIControlStateDisabled];
                    });
                    timeout --;
                }
            });
            dispatch_resume(_timer);