驗證碼倒計時按鈕的應用是非常普遍的，該Blog就和你一起來實現驗證碼倒計時的效果，定義一個發送驗證碼的按鈕，添加點擊事件，具體內容如下

具體代碼：

定義一個發送驗證碼的按鈕，添加點擊事件

 //發送驗證碼按鈕
  _sentCodeBtn = [[UIButton alloc] initWithFrame:CGRectMake(kScreenWidth - 27 - 4 - 94, CGRectGetMinY(_registerCodeFD.frame) + 4, 94, 40)];
  [_sentCodeBtn setBackgroundColor:colorWithRGBA(0, 191, 191, 0.9)];
  [_sentCodeBtn setTitle:@"發送驗證碼" forState:UIControlStateNormal];
  [_sentCodeBtn.titleLabel setFont:[UIFont systemFontOfSize:13.0f]];
  //設置圓角
  [_sentCodeBtn.layer setCornerRadius:3.0f];
  [_sentCodeBtn.layer setShouldRasterize:YES];
  [_sentCodeBtn.layer setRasterizationScale:[UIScreen mainScreen].scale];
  //發送事件
  [_sentCodeBtn addTarget:self action:@selector(sentCodeMethod) forControlEvents:UIControlEventTouchUpInside];
  [self.view addSubview:_sentCodeBtn];

監聽事件：

//發送驗證碼
-(void)sentCodeMethod{
 NSLog(@"發送驗證碼。。");
 //計時器發送驗證碼
 [self sentPhoneCodeTimeMethod];
 //調用發送驗證碼接口-》

}

//計時器發送驗證碼
-(void)sentPhoneCodeTimeMethod{
 //倒計時時間 - 60秒
 __block NSInteger timeOut = 59;
 //執行隊列
 dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
 //計時器 -》dispatch_source_set_timer自動生成
 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 (timeOut <= 0) {
   dispatch_source_cancel(timer);
   //主線程設置按鈕樣式-》
   dispatch_async(dispatch_get_main_queue(), ^{
    [_sentCodeBtn setTitle:@"發送驗證碼" forState:UIControlStateNormal];
    [_sentCodeBtn setUserInteractionEnabled:YES];
   });
  }else{
   //開始計時
   //剩余秒數 seconds
   NSInteger seconds = timeOut % 60;
   NSString *strTime = [NSString stringWithFormat:@"%.1ld",seconds];
   //主線程設置按鈕樣式
   dispatch_async(dispatch_get_main_queue(), ^{
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:1.0];
    [_sentCodeBtn setTitle:[NSString stringWithFormat:@"%@S後重新發送",strTime] forState:UIControlStateNormal];
    [UIView commitAnimations];
    //計時器件不允許點擊
    [_sentCodeBtn setUserInteractionEnabled:NO];
   });
   timeOut--;
  }
 });
 dispatch_resume(timer);
}

以上就是本文的全部內容，希望對大家的學習有所幫助。