首先你要創(chuàng)建一個按鈕肝匆，然后在按鈕的點擊事件里面寫上一下代碼即可：
__block int timeout=60; //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);
dispatch_source_set_event_handler(_timer, ^{
if(timeout<=0){ //倒計時結(jié)束问词，關閉
dispatch_source_cancel(_timer);
dispatch_async(dispatch_get_main_queue(), ^{
[self.getAuthCodeBtn setTitle:@"重新獲取" forState:UIControlStateNormal];
self.getAuthCodeBtn.userInteractionEnabled = YES;
self.getAuthCodeBtn.backgroundColor = [UIColor whiteColor];
});
}else{
int seconds = timeout;
NSString *strTime = [NSString stringWithFormat:@"%.2d", seconds];
dispatch_async(dispatch_get_main_queue(), ^{
self.getAuthCodeBtn.userInteractionEnabled = NO;
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1];
[self.getAuthCodeBtn setTitle:[NSString stringWithFormat:@"%@秒后重新發(fā)送",strTime] forState:UIControlStateNormal];
[UIView commitAnimations];
});
timeout--;
}
});
dispatch_resume(_timer);
