1 建立按鈕

 UIButton *yzmButton = [UIButton buttonWithType:UIButtonTypeCustom];
    yzmButton.backgroundColor = [UIColor orangeColor];
    yzmButton.titleLabel.font = [UIFont systemFontOfSize:13];
    [yzmButton setTitle:@"獲取驗證碼" forState:UIControlStateNormal];
    [yzmButton addTarget:self action:@selector(startTime:) forControlEvents:UIControlEventTouchUpInside];
 

    [self addSubview:yzmButton];



 [yzmButton mas_makeConstraints:^(MASConstraintMaker *make) {    make.top.mas_equalTo(weakSelf.lastLabel.mas_bottom).offset(15);       make.centerX.mas_equalTo(weakSelf.mas_centerX);
        make.size.mas_equalTo(CGSizeMake(90, 40));
    }];

2 實現點選方法

-(void)startTime:(UIButton
 
 *)l_timeButton{
    __block int timeout=59; //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(), ^{
                //設定介面的按鈕顯示 根據自己需求設定（倒計時結束後呼叫）
                [l_timeButton setTitle:@"傳送驗證碼" forState:UIControlStateNormal];
                //設定不可點選
                l_timeButton.userInteractionEnabled = YES;
                l_timeButton.backgroundColor = [UIColor orangeColor];

            });
        }else{
            //            int minutes = timeout / 60;    //這裡註釋掉了，這個是用來測試多於60秒時計算分鐘的。
            int seconds = timeout % 60;
            NSString *strTime = [NSString stringWithFormat:@"%d", seconds];
            dispatch_async(dispatch_get_main_queue(), ^{
                //設定介面的按鈕顯示 根據自己需求設定
                NSLog(@"____%@",strTime);
                [l_timeButton setTitle:[NSString stringWithFormat:@"%@秒後可重新發送",strTime] forState:UIControlStateNormal];
                //設定可點選
                l_timeButton.userInteractionEnabled = NO;
                l_timeButton.backgroundColor = [UIColor lightGrayColor];
            });
            timeout--;
        }
    });
    dispatch_resume(_timer);
}