iOS 定時器

<pre name="code" class="html">

1.CGD定時器

<pre name="code" class="objc">- (IBAction)countDown:(id)sender {
    __block int currentSeconds = 60;//設置總時間
    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_TIME_NOW, 1.0 * NSEC_PER_SEC, 0 * NSEC_PER_SEC);
    dispatch_source_set_event_handler(timer, ^{
        if (currentSeconds <= 0) {
            dispatch_source_cancel(timer);
            dispatch_async(dispatch_get_main_queue(), ^{
                self.timeButton.enabled = YES;
                [self.timeButton setTitle:@"驗證" forState:UIControlStateNormal];
            });
        } else {
            currentSeconds--;
            dispatch_async(dispatch_get_main_queue(), ^{
                self.timeButton.enabled = NO;
                [self.timeButton setTitle:[NSString stringWithFormat:@"%d秒",currentSeconds] forState:UIControlStateNormal];
            });
        }
    });
    //啓動定時器
    dispatch_resume(timer);
}

2.NSTimer定時器

<pre name="code" class="objc">-(void)lookBackClick:(UIButton *)btn
{
    
    NSDictionary *params = @{@"phone":fieldMobile.text};
    [NetworkHandle post:CAPTCHA_URL parameters:params success:^(AFHTTPRequestOperation *operation, NSDictionary *response) {
        NSLog(@"------%@",operation.responseString);
        NSDictionary *rs = [NSJSONSerialization JSONObjectWithData:operation.responseData options:NSJSONReadingMutableContainers error:nil];
        
        if (rs) {
            codeString = rs[@"ds"];
            seconds = 60;
            [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(onTimer:) userInfo:nil repeats:YES];
            [getButton setEnabled:NO];

        }
    }];
}
- (void)onTimer:(id)userInfo {
    [getButton setTitle:[NSString stringWithFormat:@"%d", --seconds] forState:UIControlStateDisabled];
    
    if (seconds == 0) {
        [getButton setTitle:@"獲取驗證碼" forState:UIControlStateNormal];
        [getButton setEnabled:YES];

        NSTimer *timer = (NSTimer *)userInfo;
        [timer invalidate];
    }
}