在公共类里面写如下两个类方法就可以了，只需要把第一个类方法公布出来：

代码如下：

#pragma mark --- 定时弹窗 ---+ (void)showAlertViewWithTitle:(NSString *)title message:(NSString *)message afterDelay:(NSTimeInterval)delay {        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title message:message delegate:nil cancelButtonTitle:nil otherButtonTitles:nil];    [alert show];    [self performSelector:@selector(dimissAlert:) withObject:alert afterDelay:delay];}+ (void)dimissAlert:(UIAlertView *)alert {    if(alert)     {        [alert dismissWithClickedButtonIndex:[alert cancelButtonIndex] animated:YES];    }}