ios - 在其他 UIPageViewController 中执行 segue

Question

我在执行 segue 操作时遇到问题。我使用 InstructionView 设置对象并在 PageViewController 类中调用它来创建新的 viewController。

我可以在哪里设置 Action ，使用 perform segue。如果我在 InstructionView 中这样做，它会崩溃。我确实将它嵌入为 NavigationController。我想我应该制作一个委托(delegate)方法，但我不知道在这种情况下如何做。

查看下面我的代码:

    protocol InstructionViewDelegate
    {
    func didTapLabel(myString: NSString)  
    }  

    class InstructionView: UIViewController
    {
    var delegate : InstructionViewDelegate!
    var pageIndex : Int = 0
    var titleText : String = ""
    var otherImageFile : String = ""

    var tapLabel = UITapGestureRecognizer()

    override func viewDidLoad()
    {
    ....

    var label = UILabel(frame: CGRectMake(16, 825, 736, 104))
    ....
    view.addSubview(label)

    var imageViewObject : UIImageView
    ....
    view.addSubview(imageViewObject)

    tapLabel = UITapGestureRecognizer(target: self, action: "imageLabelAction:")
    tapLabel.numberOfTapsRequired = 1
    label.addGestureRecognizer(tapLabel)
    label.userInteractionEnabled = true
    imageViewObject.addGestureRecognizer(tapLabel)
    imageViewObject.userInteractionEnabled = true

    }

    func imageLabelAction(sender: AnyObject)
    {
    delegate.didTapLabel("The image was tapped")
    }

页面 View Controller :

class PageViewController: UIViewController, UIPageViewControllerDataSource, InstructionViewDelegate
{
var pageViewController : UIPageViewController?
var pageTitles : Array<String> = ["", "", ""]
var otherImages : Array<String> = ["", "", ""]
var currentIndex : Int = 0

override func viewDidLoad()
{
    super.viewDidLoad()

    pageViewController = UIPageViewController(transitionStyle: .Scroll, navigationOrientation: .Horizontal, options: nil)
    pageViewController!.dataSource = self

    let startingViewController: InstructionView = viewControllerAtIndex(0)!
    let viewControllers: NSArray = [startingViewController]
    pageViewController!.setViewControllers(viewControllers, direction: .Forward, animated: false, completion: nil)
    pageViewController!.view.frame = CGRectMake(0, 0, view.frame.size.width, view.frame.size.height);

    addChildViewController(pageViewController!)
    view.addSubview(pageViewController!.view)
    pageViewController!.didMoveToParentViewController(self)
}
    func didTapLabel(myString: NSString) {
    println(myString)
    self.performSegueWithIdentifier("testSegue", sender: self)
    }


.....

func viewControllerAtIndex(index: Int) -> InstructionView?
{
    if self.pageTitles.count == 0 || index >= self.pageTitles.count{
        return nil
    }

    let pageContentViewController = InstructionView()
    pageContentViewController.otherImageFile = otherImages[index]
    pageContentViewController.titleText = pageTitles[index]
    pageContentViewController.pageIndex = index
    pageContentViewController.delegate = self
    currentIndex = index

    return pageContentViewController
}
}

Answer 1

是的，我认为代表可能是最好的途径。在您的 InstructionView Swift 文件中，定义一个协议(protocol)来描述从 InstructionView 到其委托(delegate)的通信:

protocol InstructionViewDelegate {
    func didTapLabel(myString : String)
}

我假设您将一个字符串值从 InstructionView 传回委托(delegate)；对此进行修改以反射(reflect)您实际想要传递的数据。向 InstructionView 添加一个 delegate 变量:

var delegate : InstructionViewDelegate!

同时添加一个 imageLabelAction 函数，如下所示:

func imageLabelAction(sender: AnyObject) {
    // perform any actions here in response to the label being tapped, and finish with:
    delegate.didTapLabel("The image label was tapped")
    // (amend the argument to what you need to send to your TestViewController)
}

修改PageViewController的类定义，指明它采用InstructionViewDelegate协议(protocol):

class PageViewController: UIViewController, UIPageViewControllerDataSource, InstructionViewDelegate {

请记住将 InstructionView 的委托(delegate)设置为指向自身:

startingViewController.delegate = self

然后实现协议(protocol)定义的功能:

func didTapLabel(myString: String) {
    println(myString)
    // do any processing here (e.g. save myString to a local var)
    // before triggering the segue:
    self.performSegueWithIdentifier("FromPageVCtoTestVC", sender: self)
}

然后您可以使用 prepareForSegue 以通常的方式将相关数据传递到目标 View Controller 。