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后重新發送",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。
