iOS 短信验证码倒计时按钮的实现

引言:

验证码倒计时按钮的应用是非常普遍的，本文介绍了IOS实现验证码倒计时功能，点击获取验证码，进入时间倒计时，感兴趣的小伙伴们可以参考一下

效果图

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实现思路:

• 创建按钮, 添加点击方法;
• 用NSTimer定时器, 每秒执行一次, 定时改变Button的title,改变Button的样式, 设置Button不可点击;
• 若倒计时结束, 定时器关闭, 并改变Button的样式, 可以点击;

代码如下:

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// 开启倒计时效果 -(void)openCountdown{     __block NSInteger time = 59; //倒计时时间     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); //每秒执行       dispatch_source_set_event_handler(_timer, ^{         if(time <= 0){ //倒计时结束，关闭             dispatch_source_cancel(_timer);             dispatch_async(dispatch_get_main_queue(), ^{                   //设置按钮的样式                 [self.authCodeBtn setTitle:@"重新发送" forState:UIControlStateNormal];                 [self.authCodeBtn setTitleColor:[UIColor colorFromHexCode:@"FB8557"] forState:UIControlStateNormal];                 self.authCodeBtn.userInteractionEnabled = YES;             });           }else{             int seconds = time % 60;             dispatch_async(dispatch_get_main_queue(), ^{                   //设置按钮显示读秒效果                 [self.authCodeBtn setTitle:[NSString stringWithFormat:@"重新发送(%.2d)", seconds] forState:UIControlStateNormal];                 [self.authCodeBtn setTitleColor:[UIColor colorFromHexCode:@"979797"] forState:UIControlStateNormal];                 self.authCodeBtn.userInteractionEnabled = NO;             });             time--;         }     });     dispatch_resume(_timer); }

在按钮的点击事件里调用该方法.

注意点:

我们在创建Button时, 要设置Button的样式:
当type为: UIButtonTypeCustom时 , 是读秒的效果.
当type为: 其他时, 是一闪一闪的效果.