IOS AlertView 自动消失

UIAlertView *alert;

- (IBAction)Open:(id)sender {

    alert = [[UIAlertView alloc]

                          initWithTitle:@"msg" message:@"sss" delegate:self cancelButtonTitle:@"取消" otherButtonTitles:@"确定", nil];

    [NSTimer scheduledTimerWithTimeInterval:5.0f target:self selector:@selector(performDismiss:) userInfo:nil repeats:NO];

    [alert show];

    

}

-(void)performDismiss:(NSTimer*)timer

{

    [alert dismissWithClickedButtonIndex:0 animated:NO];

}