【转】iOS 短信验证码倒计时按钮的实现

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:

在按钮的点击事件里调用该方法.

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// 开启倒计时效果
-(void)openCountdown:(UIButton*)sender{
__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
[sender setTitle:@"重新发送" forState:UIControlStateNormal];
[sender setTitleColor:[UIColor colorFromHexCode:@"FB8557"] forState:UIControlStateNormal];
sender.userInteractionEnabled = YES;
});
}else{
int seconds = time % 60;
dispatch_async(dispatch_get_main_queue(), ^{
//设置按钮显示读秒效果
[sender setTitle:[NSString stringWithFormat:@"重新发送(%.2d)", seconds] forState:UIControlStateNormal];
[sender setTitleColor:[UIColor colorFromHexCode:@"979797"] forState:UIControlStateNormal];
sender.userInteractionEnabled = NO;
});
time--;
}
});
dispatch_resume(_timer);
}

作者:Li_Cheng
链接:https://www.jianshu.com/p/2104865e7dba
來源:简书