ios - 在 viewdidappear 中快速呈现模态

Question

一般来说，我是 swift 和 ios 编程的新手。我正在尝试在我的应用程序首次加载时显示模态视图。我遇到的问题是我的模式一遍又一遍地出现。不确定我哪里出错了。

红利问题:最终我希望只在用户第一次打开应用时发生这种情况。

class ViewController: UIViewController {

    var introModalDidDisplay = false

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        showIntroModal()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func showIntroModal() {
        if (!introModalDidDisplay) {
            println(introModalDidDisplay)
            introModalDidDisplay = true
            let intro = self.storyboard?.instantiateViewControllerWithIdentifier("introModal") as IntroModalViewController
            intro.modalPresentationStyle = UIModalPresentationStyle.FormSheet
            self.presentViewController(intro, animated: true, completion: nil)
        }
    }
}

Answer 1

找到了。我的“介绍”类正在扩展 ViewController 而不是 UIViewController...显然这很糟糕。谢谢您的帮助!对不起，我的胡思乱想。