1. 定時器

• 倒計時按鈕

// UIButton Category
- (void)startTimeAtCodeButton {
    __block int timeout = 60; //倒計時時間
    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); //每秒執行
    dispatch_source_set_event_handler(_timer, ^{
        if(timeout<=0){ //倒計時結束，關閉
            dispatch_source_cancel(_timer);
            dispatch_async(dispatch_get_main_queue(), ^{
                //設置界面的按鈕顯示 根據自己需求設置
                [self setTitle:@"發送驗證碼" forState:UIControlStateNormal];
                [self setTitleColor:k_Color_FF9331 forState:UIControlStateNormal];
                self.contentMode = UIViewContentModeLeft;
                self.userInteractionEnabled = YES;
            });
        }else{
            //            int minutes = timeout / 60;
            int seconds = timeout % 61;
            NSString *strTime = [NSString stringWithFormat:@"%.2d", seconds];
            dispatch_async(dispatch_get_main_queue(), ^{
                //設置界面的按鈕顯示 根據自己需求設置
                [self setTitle:[NSString stringWithFormat:@"再次發送%@秒",strTime] forState:UIControlStateNormal];
                [self setTitleColor:k_Color_cccccc forState:UIControlStateNormal];
                self.contentMode = UIViewContentModeCenter;
                self.userInteractionEnabled = NO;
            });
            timeout--;
        }
    });
    dispatch_resume(_timer);
}

• 點擊彈出
  • 按鈕用System樣式有很多詭異的問題，用Custom樣式