Question

我有一个名为UIViewController的{{1}}，其中包含另外两个孩子Container：UIViewControllers和Master。

我的问题是尝试从其中一个子控制器访问Detail。

App代表代码：

Container

货柜代码：

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?
    var container: Container?

    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        window = UIWindow(frame: UIScreen.mainScreen().bounds)
        container = Container(nibName: "Container", bundle: nil)
        window?.rootViewController = Container()
        window?.makeKeyAndVisible()
        return true
    }

    func appShowDetailView(vc:UIViewController){
        container!.showDetailView(vc)
    }
}

问题在于import UIKit class Container: UIViewController { var masterView:UIViewController? var detailView:UIViewController? var masterViewFrame = CGRectMake(0, 0, 0, 0) var detailViewFrame = CGRectMake(0, 0, 0, 0) var detailOnScreenFrame = CGRectMake(0, 0, 0, 0) var detailOffScreenFrame = CGRectMake(0, 0, 0, 0) var masterViewHeight:CGFloat = 50 override func viewDidLoad() { super.viewDidLoad() masterView = MenuViewController(nibName: "MenuViewController", bundle: nil) detailView = RootViewController(nibName: "RootViewController", bundle: nil) masterViewFrame = CGRectMake(0, 0, self.view.frame.width, masterViewHeight) detailViewFrame = CGRectMake(0, masterViewHeight, self.view.frame.width, self.view.frame.height - masterViewHeight) detailOffScreenFrame = CGRectMake(detailViewFrame.origin.x, detailViewFrame.origin.y + detailViewFrame.height, detailViewFrame.width, detailViewFrame.height) detailOnScreenFrame = detailViewFrame self.addChildViewController(masterView!) self.addChildViewController(detailView!) masterView!.view.frame = masterViewFrame detailView!.view.frame = detailViewFrame self.view.addSubview(masterView!.view) self.view.addSubview(detailView!.view) } func cycleDetailView(from:UIViewController, toView to:UIViewController){ from.willMoveToParentViewController(nil) self.addChildViewController(to) to.view.frame = self.detailOffScreenFrame self.detailView = to self.transitionFromViewController(from, toViewController: to, duration: 0.25, options: UIViewAnimationOptions.allZeros, animations: {() -> Void in // send the new view controller in, and the old one out to.view.frame = self.detailOnScreenFrame from.view.frame = self.detailOffScreenFrame }, completion: {success -> Void in // tells the view controllers cycling has ended from.removeFromParentViewController() to.didMoveToParentViewController(self) } ) } func showDetailView(vc: UIViewController){ if let oldView = detailView { cycleDetailView(oldView, toView: vc) }else{ detailView = self.childViewControllers[1] as? UIViewController if let oldView = detailView { cycleDetailView(oldView, toView: vc) }else{ } } } }。当这个代码被这样的代码调用时：

showDetailView()

...容器函数let appDelegate = UIApplication.sharedApplication().delegate as? AppDelegate if let delegateUnwrapped = appDelegate { delegateUnwrapped.appShowDetailView(aViewController) }只能为showDetailView()获取nil值，而detailView是一个空数组。

这让我觉得我以错误的方式访问子视图控制器。

谁能告诉我哪里出错了？

TIA。

Answer 1

我认为你的问题是app delegate中的这一行，

 window?.rootViewController = Container()

这将创建一个Container的新实例，而不是您分配给容器属性的实例。将该行更改为，

window?.rootViewController = container

从其子UIViewControllers访问父UIViewController

1 个答案: