iOS 驗證碼按鈕倒計時，ios驗證碼

iOS 驗證碼按鈕倒計時，ios驗證碼

 

在app 註冊或者登入 需要驗證碼的地方、為了避免短時間內刷驗證碼、往往會加上一層驗證。

 

倒計時結束後、可以重新擷取！

 

代碼實現如下：

 

// _CountdownTime 倒計時總時間；

//_timer 定時器

- (void)startTime:(UIButton *)VerificationCodeButton {    __block NSInteger timeout = [_CountdownTime integerValue];        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);    dispatch_source_set_event_handler(_timer, ^{        if(timeout<=0){            dispatch_source_cancel(_timer);            dispatch_async(dispatch_get_main_queue(), ^{                [VerificationCodeButton setTitle:@"重新擷取" forState:UIControlStateNormal];                VerificationCodeButton.userInteractionEnabled = YES;                VerificationCodeButton.alpha = 1.0;                VerificationCodeButton.backgroundColor = [UIColor whiteColor];            });        } else {            NSString *strTime = [NSString stringWithFormat:@"%lds", (long)timeout];            dispatch_async(dispatch_get_main_queue(), ^{                [VerificationCodeButton setTitle:strTime forState:UIControlStateNormal];                VerificationCodeButton.userInteractionEnabled = NO;                VerificationCodeButton.backgroundColor = [UIColor lightTextColor];            });            timeout--;        }    });    dispatch_resume(_timer);}