关于ios：所有IBOutlets都为零

All IBOutlets are nil

您好，我正在使用以下代码初始化viewController：

1	var aboutUsViewController = self.storyboard?.instantiateViewControllerWithIdentifier("AboutUsViewController") as AboutUsViewController

此后，我移至aboutViewController。但是我在aboutViewController上的所有IBOutlets都是nil！为什么会这样？
我正在使用MMDrawer库以具有侧边栏菜单。

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var aboutUsViewController = self.storyboard?.instantiateViewControllerWithIdentifier("AboutUsViewController") as AboutUsViewController

var aboutUsNavController = UINavigationController(rootViewController: aboutUsViewController)

var appDelegate: AppDelegate = UIApplication.sharedApplication().delegate as AppDelegate

appDelegate.centerContainer!.centerViewController = aboutUsNavController
appDelegate.centerContainer!.toggleDrawerSide(MMDrawerSide.Left, animated: true, completion: nil)

在侧栏上，我选择关于我们的菜单项，然后在创建AboutViewController并将其移到左侧...问题是，当我初始化控制器时，出口为nil

我在使用pageViewController时也遇到此类问题：

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class ViewController: UIViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate {

let pageTitles = ["Title 1","Title 2","Title 3","Title 4"]
var images = ["long3","long4","long1","long2"]
var count = 0

var pageViewController : UIPageViewController!

override func viewDidLoad() {
super.viewDidLoad()
reset()
// 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.
}

func reset() {
/* Getting the page View controller */
pageViewController = self.storyboard?.instantiateViewControllerWithIdentifier("PageViewController") as UIPageViewController
self.pageViewController.dataSource = self

let pageContentViewController = self.viewControllerAtIndex(0)
self.pageViewController.setViewControllers([pageContentViewController!], direction: UIPageViewControllerNavigationDirection.Forward, animated: true, completion: nil)

/* We are substracting 30 because we have a start again button whose height is 30*/
self.pageViewController.view.frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.height - 30)
self.addChildViewController(pageViewController)
self.view.addSubview(pageViewController.view)
self.pageViewController.didMoveToParentViewController(self)
}

func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {

var index = (viewController as PageContentViewController).pageIndex!
index++
if (index >= self.images.count){
return nil
}

return self.viewControllerAtIndex(index)
}

func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
var index = (viewController as PageContentViewController).pageIndex!

if index<=0 {
return nil
}
index--
return self.viewControllerAtIndex(index)
}

func viewControllerAtIndex(index : Int) -> UIViewController? {
if((self.pageTitles.count == 0) || (index >= self.pageTitles.count)) {
return nil
}
let pageContentViewController = self.storyboard?.instantiateViewControllerWithIdentifier("PageContentViewController") as PageContentViewController

pageContentViewController.imageName = self.images[index]
pageContentViewController.titleText = self.pageTitles[index]
pageContentViewController.pageIndex = index
return pageContentViewController
}

func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int {
return pageTitles.count
}

func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int {
return 0
}

}

class PageContentViewController: UIPageViewController {

@IBOutlet var imageViewMain: UIImageView!

@IBOutlet var labelMain: UILabel!

var pageIndex: Int!
var titleText: String!
var imageName: String!

override func viewDidLoad() {
super.viewDidLoad()

self.imageViewMain.image = UIImage(named:imageName)
self.labelMain.text = self.titleText
self.labelMain.alpha = 0.1
UIView.animateWithDuration(1.0, animations:{ ()-> Void in
self.labelMain.alpha = 1.0
})
// Do any additional setup after loading the view.
}

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

/*
// MARK: - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
}
*/

}

我遇到标签和图像出口为零的问题！！！我在使用MMDrawer库时遇到了同样的问题。同样的情况。我没有使用segues！我认为因为这个网点是nil

相关讨论

我假设您在实例化场景后立即查看outlets(如果使用segues并尝试使用prepareForSegue中的outlets，您还将看到此行为)。但是直到您呈现/推送到该场景，加载视图并调用viewDidLoad之后，outlets才会被连接。

最重要的是，请勿在调用viewDidLoad之前尝试使用outlets(即，在实例化场景后不要立即使用outlets)。而是将所需的数据传递到目标场景(例如String属性)，然后目标的viewDidLoad应该填充出口。

例如，您可能在AboutUsViewController中具有一个属性：

1	var message: String!

实例化AboutUsViewController时，需要设置该属性：

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let aboutUsViewController = self.storyboard?.instantiateViewControllerWithIdentifier("AboutUsViewController") as AboutUsViewController // use `as!` in Swift 1.2

aboutUsViewController.message ="some message"

presentViewController(aboutUsViewController, animated: true, completion: nil)

，然后AboutUsViewController的viewDidLoad将使用该属性相应地填充出口：

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override func viewDidLoad() {
super.viewDidLoad()

label1.text = message
}

但是您永远不会让原始视图控制器尝试设置/调整目标场景的出口。这是AboutUsViewController。

的责任。

只需确认一下，您的outlets是否正确连接？下面显示了两种方法来确认它们已正确连接。

当您在Interface Builder中选择视图控制器，然后在连接检查器中查看时，您是否看到outlets钩在那里？在以下快照中，连接了label1，但没有连接label2：

enter