倒计时总是要上网去找 直接放个笔记在这得了
新建UIbutton子类,然后用这个button就好了
.m中
#define SendCode @"发送验证码"
@interface PEMCodeButton()
{
dispatch_source_t _timer;
}
@end
@implementation PEMCodeButton
- (void) startSend
{
[self openCountdown:NO];
}
- (void)endSending
{
dispatch_source_cancel(_timer);
dispatch_async(dispatch_get_main_queue(), ^{
//设置按钮的样式
[self setTitle:SendCode forState:UIControlStateNormal];
self.userInteractionEnabled = YES;
});
}
// 开启倒计时效果
-(void)openCountdown:(BOOL) isFail{
__blockNSIntegertime =59;//倒计时时间
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
_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|| isFail){//倒计时结束，关闭
dispatch_source_cancel(_timer);
dispatch_async(dispatch_get_main_queue(), ^{
//设置按钮的样式
[self setTitle:SendCode forState:UIControlStateNormal];
self.userInteractionEnabled = YES;
});
}else{
intseconds = time %60;
dispatch_async(dispatch_get_main_queue(), ^{
//设置按钮显示读秒效果
[self setTitle:[NSString stringWithFormat:@"重新发送(%.2d)", seconds] forState:UIControlStateNormal];
self.userInteractionEnabled = NO;
});
time--;
}
});
dispatch_resume(_timer);
}
.h中
- (void) startSend;//开始倒计时
- (void)endSending;//请求服务器失败关闭倒计时