使用NavigationViewController swift呈现ViewController

Question

我有系统“NavigationViewController - > MyViewController”，我编程想要在第三个视图控制器中呈现MyViewController。 问题是我在呈现它之后在MyViewController中没有导航栏。 你能帮助我吗？

var VC1 = self.storyboard.instantiateViewControllerWithIdentifier("MyViewController") as ViewController
self.presentViewController(VC1, animated:true, completion: nil)

Answer 1

调用presentViewController在现有导航堆栈之外以模态 presentViewController呈现视图控制器; 它不包含在您的UINavigationController或任何其他内容中。 如果您希望新视图控制器具有导航栏，则有两个主要选项：

选项1.将新视图控制器推送到现有导航堆栈，而不是以模态方式呈现：

let VC1 = self.storyboard!.instantiateViewControllerWithIdentifier("MyViewController") as! ViewController
self.navigationController!.pushViewController(VC1, animated: true)

选项2.将新视图控制器嵌入到新的导航控制器中，并以模态方式显示新的导航控制器：

let VC1 = self.storyboard!.instantiateViewControllerWithIdentifier("MyViewController") as! ViewController
let navController = UINavigationController(rootViewController: VC1) // Creating a navigation controller with VC1 at the root of the navigation stack.
self.present(navController, animated:true, completion: nil)

请记住，此选项不会自动包含“后退”按钮。 你必须自己建立一个紧密的机制。

哪个最适合您的是人机界面设计问题，但通常清楚哪些是最有意义的。

Answer 2

SWIFT 3

let VC1 = self.storyboard!.instantiateViewController(withIdentifier: "MyViewController") as! MyViewController
let navController = UINavigationController(rootViewController: VC1)
self.present(navController, animated:true, completion: nil)

Answer 3

我的导航栏没有显示，所以我在Swift 2 iOS 9中使用了以下方法

let viewController = self.storyboard?.instantiateViewControllerWithIdentifier("Dashboard") as! Dashboard

// Creating a navigation controller with viewController at the root of the navigation stack.
let navController = UINavigationController(rootViewController: viewController)
self.presentViewController(navController, animated:true, completion: nil)

Answer 4

我使用了UIViewController的扩展和一个结构来确保我的当前视图是从收藏夹中显示的

1.构建全球Bool

struct PresentedFromFavourites {
static var comingFromFav = false}

2.UIVeiwController扩展：通过“stefandouganhyde - Option 2”在第二个选项中以模态方式呈现并解决后面的问题

extension UIViewController {
func returnToFavourites()
{
    // you return to the storyboard wanted by changing the name
    let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
    let mainNavigationController = storyBoard.instantiateViewController(withIdentifier: "HomeNav") as! UINavigationController
    // Set animated to false
    let favViewController = storyBoard.instantiateViewController(withIdentifier: "Favourites")
    self.present(mainNavigationController, animated: false, completion: {
        mainNavigationController.pushViewController(favViewController, animated: false)
    })

}
// call this function in viewDidLoad()
// 
func addBackToFavouritesButton()
{
    if PresentedFromFavourites.comingFromFav
    {
        //Create a button
        // I found this good for most size classes
        let buttonHeight = (self.navigationController?.navigationBar.frame.size.height)! - 15
        let rect = CGRect(x: 2, y: 8, width: buttonHeight, height: buttonHeight)
        let aButton = UIButton(frame: rect)
        // Down a back arrow image from icon8 for free and add it to your image assets  
        aButton.setImage(#imageLiteral(resourceName: "backArrow"), for: .normal)
        aButton.backgroundColor = UIColor.clear
        aButton.addTarget(self, action:#selector(self.returnToFavourites), for: .touchUpInside)
        self.navigationController?.navigationBar.addSubview(aButton)
        PresentedFromFavourites.comingFromFav = false
    }

}}

Answer 5

接受的答案很棒。 这不是答案，只是对问题的说明。

我提出了一个像这样的viewController：

在vc1里面：

func showVC2() {
    if let navController = self.navigationController{
        navController.present(vc2, animated: true)
    }
}

在vc2里面：

func returnFromVC2() {
    if let navController = self.navigationController {
        navController.popViewController(animated: true)
    }else{
        print("navigationController is nil") <-- I was reaching here!
    }
}

正如'stefandouganhyde'所说：“它不是由你的UINavigationController或任何其他包含的”

新解决方案：

func returnFromVC2() {
    dismiss(animated: true, completion: nil)
}