實例化視圖，然後導航

Question

我目前正在編寫一個應用程序，我們在用戶第一次打開該應用程序時啓動漫遊。最後，我們要求用戶填寫一些細節，爲此我希望他按下按鈕以重定向到設置頁面。

問題是，此頁面位於導航控制器的下一級（從着陸頁開始）。就目前而言，我可以正確實例化着陸頁，但重定向到設置頁面從不發生。

let mainView = self.storyboard?.instantiateViewControllerWithIdentifier("NavCtrl") 
self.presentViewController(mainView!, animated: false, completion: nil) 
// the above works correctly and sends us to the landing screen 
// (rootView of the navigation controller) 

// the following lines never have any effect though 
let settingsView = self.storyboard?.instantiateViewControllerWithIdentifier("Settings View") 
self.navigationController?.pushViewController(settingsView!, animated: false) 

我想這是因爲我試圖打電話.pushViewController故事板來得及instiate第一或第二視圖之前。

所以，我有幾個問題：

• 有沒有一種辦法，實際上，創建一個視圖，然後導航到另外一個已經被實例化後，對不對？ （這是爲了保持導航堆棧並保持準確的導航欄行爲）
• 如果沒有，是否有可能以編程方式填充導航堆棧，以便我只需要實例化設置視圖？這是爲了在導航欄中仍然有後退按鈕可以發送到登陸屏幕？

在此先感謝球員

Answer 1

感謝@Leonardo向我展示正確的方向！

我在做的appDelegate以下解決問題：

/* 
* Override window root view and set it to a newly initialized one 
* view: StoryboardID of view to display 
* navigateTo: if true, set the root view to NavCtrl and then navigate to the desired view 
*/ 
func setWindowViewTo(view: String, navigateTo: Bool) { 

    //initalize storyboard & window programmatically 
    window = UIWindow.init(frame: UIScreen.mainScreen().bounds) 
    let storyboard = UIStoryboard(name: "Main", bundle: nil) 

    //if true, navigate from landing page to specified view through navigationController 
    if(navigateTo) { 

     //instantiate the navigation controller 
     let navCtrl = storyboard.instantiateViewControllerWithIdentifier("NavCtrl") as! UINavigationController 

     //instantiate the landing page & the page we wish to navigate to 
     let landingView = storyboard.instantiateViewControllerWithIdentifier("Main View") 
     let vc = storyboard.instantiateViewControllerWithIdentifier(view) 

     //manually set the navigation stack to landing view + view to navigate to 
     navCtrl.setViewControllers([landingView, vc], animated: false) 

     //replace the rootViewController to the navigation controller 
     window!.rootViewController = navCtrl 

     //make it work 
     window!.makeKeyAndVisible() 

    } else { 
     window!.rootViewController = storyboard.instantiateViewControllerWithIdentifier(view) 
     window!.makeKeyAndVisible() 
    } 
} 

的重要步驟是與storyboard.instantiateViewControllerWithIdentifier()方法實例化NavigationController時確實迫使垂頭喪氣as! UINavigationController。

然後，您只需要正確實例化您想要的導航堆棧的視圖，最後再調用navCtrl.setViewControllers([view1, view2], animate: false)。

謝謝大家的幫助！

Answer 2

可以使用- setViewControllers:animated:方法來設置的UINavigationController

導航堆棧這裏的reference

但我不認爲這是你的問題，如果我不能正確地代碼您的代碼，它應該是

//This is the navigation controller 
if let mainView = self.storyboard?.instantiateViewControllerWithIdentifier("NavCtrl"){ 

    //Nav being modally presented 
    self.presentViewController(mainView, animated: false, completion: nil) 

    // Instantiate the settings view 
    if let settingsView = self.storyboard?.instantiateViewControllerWithIdentifier("Settings View"){ 
     //Push it to the navigation controller presented 
     mainView.pushViewController(settingsView, animated: false) 
    } 
    else{ 
     //Can't Instantiate, deal with error 
    } 
} 
else{ 
    //Can't Instantiate, deal with error 
}