在 Swift 中关闭和呈现视图控制器

Question

您好，我正在尝试展示一个视图控制器并关闭我当前的模态视图，但此代码不起作用

self.dismissViewControllerAnimated(true, completion: {
    let vc = self.storyboard?.instantiateViewControllerWithIdentifier("OrderViewController")
    self.presentViewController(vc!, animated: true, completion: nil)
})

反之亦然在presentviewcontroller的完成块上也不起作用

编辑：替换 vc！给自己

Answer 1

我认为您的代码中有一个错误，其中“self”应该是呈现“vc”的呈现视图控制器，而不是“vc”它的自我

你的代码

self.dismissViewControllerAnimated(true, completion: {
                let vc = self.storyboard?.instantiateViewControllerWithIdentifier("OrderViewController")
                vc!.presentViewController(vc!, animated: true, completion: nil)
            })

试试这个

self.dismissViewControllerAnimated(true, completion: {
                let vc = self.storyboard?.instantiateViewControllerWithIdentifier("OrderViewController")
                self.presentViewController(vc!, animated: true, completion: nil)
            })

希望对你有帮助

Answer 2

您必须获取呈现自我的视图控制器（当前视图控制器）。如果该视图控制器是 rootViewController，那么您可以使用下面的代码，如果不是，则根据您的视图控制器层次结构查询它。

if let vc3 = self.storyboard?.instantiateViewController(withIdentifier: "vc3") as? ViewController3 {
    let appDelegate = UIApplication.shared.delegate as! AppDelegate
    appDelegate.window?.rootViewController!.present(vc3, animated: true, completion: nil)
}

Answer 3

let parent = self.parentViewController!

parent.dismissViewControllerAnimated(true, completion: {
            let vc = self.storyboard?.instantiateViewControllerWithIdentifier("OrderViewController")
            parent.presentViewController(vc!, animated: true, completion: nil)
        })

Answer 4

您不能这样做，因为当 UIViewController A 调用 UIViewController B 并且第一个控制器被解除时，这两个控制器为零。

您需要有一个 UIViewController 作为基础，在这种情况下 MainViewController 是基础。您需要使用协议来调用控制器之间的导航。

你可以使用协议让我们说如下：-

在您的 viewController 设置协议中：

    protocol FirstViewControllerProtocol {
    func dismissViewController()
}

class FirstViewController: UIViewController {
    var delegate:FirstViewControllerProtocol!

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

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


    @IBAction func goBack(sender: AnyObject) {
        self.dismissViewControllerAnimated(true) { 
            self.delegate!.dismissViewController()
        }
    }

现在在你的主视图控制器中

class MainViewController: UIViewController, FirstViewControllerProtocol {

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

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


@IBAction func goToFirstViewController(sender: AnyObject) {
    let viewController = self.storyboard?.instantiateViewControllerWithIdentifier(String(FirstViewController)) as! FirstViewController
    viewController.delegate = self
    self.presentViewController(viewController, animated: true, completion: nil)
}



//MARK: Protocol
func dismissViewController() {
    if let viewController = self.storyboard?.instantiateViewControllerWithIdentifier(String(SecondViewController)){
        self.presentViewController(viewController, animated: true, completion: nil)
    }
}

Code example with storyboard:

---

Answer 5

这是 Swift3 的解决方案

展示 ViewController

let NotificationVC = self.storyboard?.instantiateViewController(withIdentifier: "NotificationVC") as! ExecutiveNotificationViewController

self.present(NotificationVC, animated: true, completion: nil)

关闭 ViewController：

self.dismiss(animated: true, completion: nil)