先声明UIButton
UIButton*firstBtn;
firstBtn = [[UIButton alloc] initWithFrame:CGRectMake(200, 160, 60, 40)];
[firstBtn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[firstBtn setTitle:@"60" forState:UIControlStateNormal];
[firstBtn addTarget:self action:@selector(tagehend) forControlEvents:UIControlEventAllEvents];
[self.view addSubview:firstBtn];
-(void)tagehend{
__blockNSIntegertimeOut =59;
//执行队列
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
//计时器 -》dispatch_source_set_timer自动生成
dispatch_source_ttimer =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);
//主线程设置按钮样式-》
dispatch_async(dispatch_get_main_queue(), ^{
[self->firstBtnsetTitle:@"发送验证码"forState:UIControlStateNormal];
[self->firstBtn setUserInteractionEnabled:YES];
});
}else{
//开始计时
//剩余秒数 seconds
NSIntegerseconds = timeOut %60;
NSString*strTime = [NSStringstringWithFormat:@"%.1ld",seconds];
//主线程设置按钮样式
dispatch_async(dispatch_get_main_queue(), ^{
[UIViewbeginAnimations:nilcontext:nil];
[UIViewsetAnimationDuration:1.0];
[self->firstBtn setTitle:[NSString stringWithFormat:@"%@",strTime] forState:UIControlStateNormal];
[UIViewcommitAnimations];
//计时器件不允许点击
[self->firstBtn setUserInteractionEnabled:NO];
});
timeOut--;
}
});
dispatch_resume(timer);
}