iOS开发总结 - 倒计时按钮

__block int timeout = 89; //设置倒计时时间 90秒

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(), ^{//设置倒计时结束重置操作

[_getSecurityCodeBtn setTitle:@"获取验证码" forState:UIControlStateNormal];

_getSecurityCodeBtn.userInteractionEnabled = YES;

});

}else{

int seconds = timeout % 90;

NSString *strTime = [NSString stringWithFormat:@"%d秒后重新发送", seconds];

dispatch_async(dispatch_get_main_queue(), ^{

[UIView beginAnimations:nil context:nil];

[UIView setAnimationDuration:1];

[_getSecurityCodeBtn setTitle:strTime forState:UIControlStateNormal];

[UIView commitAnimations];

_getSecurityCodeBtn.userInteractionEnabled = NO;

});

timeout--;

}

});

dispatch_resume(_timer);