SheaYang小学

[self.vCodeBtn setEnabled:NO];
count = 60;
NSTimer *time = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(openFire:) userInfo:nil repeats:YES];
-函数实现方法：
-(void)openFire:(NSTimer *)time
{
count–;
NSString *miao = [NSString stringWithFormat:@”%ld”,(long)count];
[self.vCodeBtn setTitle:miao forState:0];
if (count == 1)
{
[self.vCodeBtn setTitle:@”Reacquire” forState:0];
[self.vCodeBtn setEnabled:YES];
[time invalidate];
}
}

第二种：使用GCD来实现：

__block int timeout=300; //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_release(_timer);
dispatch_async(dispatch_get_main_queue(), ^{
//设置界面的按钮显示 根据自己需求设置
。。。。。。。。
});
}else{
int minutes = timeout / 60;
int seconds = timeout % 60;
NSString *strTime = [NSString stringWithFormat:@”%d分%.2d秒后重新获取验证码”,minutes, seconds];
dispatch_async(dispatch_get_main_queue(), ^{
//设置界面的按钮显示 根据自己需求设置
。。。。。。。。
});
timeout–;
}
});
dispatch_resume(_timer);