__block int timeout = 10 ; //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(timeout<=0){ //倒计时结束，关闭
dispatch_source_cancel(_timer);
dispatch_async(dispatch_get_main_queue(), ^{
//设置界面的按钮显示
[sender setTitle:@"发送验证码" forState:UIControlStateNormal];
sender.enabled = YES;
});
}else{
int seconds = timeout % 60;
NSString *strTime = [NSString stringWithFormat:@"%d", seconds];
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(@"----%@", [NSThread currentThread]);
//设置界面的按钮显示
[sender setTitle:[NSString stringWithFormat:@"(%@)重新获取",strTime] forState:UIControlStateDisabled];
sender.enabled = NO;
});
timeout--;
}
});
dispatch_resume(_timer);
- 主要问题：按钮进入倒计时状态后，按钮闪烁似小星星
- 解决方案
- 将按钮类型改为custome
- 在按钮上边罩一个相同大小的UILabel，更新此label即可
