在 Xcode 场景 Swift iOS 中集成 Facebook 和 Twitter

Question

我在 Xcode 中使用 sprite kit 和场景开发了一个游戏。现在我正在尝试集成将高分发布到 twitter 和 Facebook 的功能。我环顾四周，大多数人说使用 SLComposeServiceViewController 很好，直到我尝试展示它。因为我的应用程序真的只使用场景，所以它们从来没有成员函数“presentViewController(....)”。因此，我永远无法呈现它。有谁知道解决这个问题的方法吗？

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

    let touch:UITouch = touches.first!
    let touchLocation = touch.location(in: self)
    let touchedNode = self.atPoint(touchLocation)

    if (touchedNode.name == "tryAgain") {
        let nextScene = Scene_LiveGame(size: self.scene!.size)
        nextScene.scaleMode = self.scaleMode
        self.view?.presentScene(nextScene, transition: SKTransition.fade(withDuration: 0.5))
    }
    else if (touchedNode.name == "share") {

        if SLComposeViewController.isAvailable(forServiceType: SLServiceTypeFacebook) {

        let fShare = SLComposeViewController(forServiceType: SLServiceTypeFacebook)



        self.presentViewController(fShare!, animated: true, completion: nil)
         //^This is where my problem is. Xcode is telling me that self has no member function presentViewController which I totally understand, because its a scene and thus doesn't share those functions. But every resource online has shown me this is the only way to do it   

        }

    }

Answer 1

您收到此错误是因为您需要从另一个 UIViewController 呈现一个 UIViewController。所以

self.presentViewController(...)

将不起作用，因为 self (SKScene) 不是 UIViewController。要从 SKScene 呈现，您必须这样说

view?.window?.rootViewController?.presentViewController(fShare!, animated: true, completion: nil)

我建议您不要再使用这些 API。最好使用 UIActivityViewController 来满足您的共享需求。这样，您的应用中只需要一个分享按钮，您就可以分享到各种服务（电子邮件、Twitter、Facebook、iMessage、WhatsApp 等）。

创建一个新的 Swift 文件并添加此代码。

enum ShareMenu {

    static func open(text: String, image: UIImage?, appStoreURL: String?, from viewController: UIViewController?) {
        guard let viewController = viewController, let view = viewController.view else { return }

    // Activity items
    var activityItems = [Any]()

    // Text
    activityItems.append(text)

    // Image
    if let image = image {
        activityItems.append(image)
    }

    /// App url
    if let appStoreURL = appStoreURL {
        let items = ActivityControllerItems(appStoreURL: appStoreURL)
        activityItems.append(items)
    }

    // Activity controller
    let activityController = UIActivityViewController(activityItems: activityItems, applicationActivities: nil)

    // iPad settings
    if UIDevice.current.userInterfaceIdiom == .pad {
        activityController.modalPresentationStyle = .popover
        activityController.popoverPresentationController?.sourceView = view
        activityController.popoverPresentationController?.sourceRect = CGRect(x: view.bounds.midX, y: view.bounds.midY, width: 0, height: 0)
        activityController.popoverPresentationController?.permittedArrowDirections = UIPopoverArrowDirection.init(rawValue: 0)
    }

    // Excluded activity types
    activityController.excludedActivityTypes = [
        .airDrop,
        .print,
        .assignToContact,
        .addToReadingList,
    ]

    // Present
    DispatchQueue.main.async {
        viewController.present(activityController, animated: true)
    }

    // Completion handler
    activityController.completionWithItemsHandler = { (activity, success, items, error) in
        guard success else {
            if let error = error {
                print(error.localizedDescription)
            }
            return
        }

            // do something if needed
       }
   } 
}
// MARK: - Activity Controller Items

/**
 ActivityControllerItems
 */
private final class ActivityControllerItems: NSObject {

    // MARK: - Properties

    /// App name
    fileprivate let appName = Bundle.main.infoDictionary?["CFBundleName"] as? String ?? "-"

    /// App store web url
    fileprivate let appStoreURL: String

    // MARK: - Init

    /// Init
    fileprivate init(appStoreURL: String) {
        self.appStoreURL = appStoreURL
        super.init()
    }
}

// MARK: - UIActivityItemSource

/// UIActivityItemSource
extension ActivityControllerItems: UIActivityItemSource {

    /// Getting data items

    /// Placeholder item
    func activityViewControllerPlaceholderItem(_ activityViewController: UIActivityViewController) -> Any {
        return ""
    }

    /// Item for actity type
    func activityViewController(_ activityViewController: UIActivityViewController, itemForActivityType activityType: UIActivityType) -> Any? {
        return URL(string: appStoreURL) ?? appName
    }

    /// Provide info about data items

    /// Subject field for services such as email
    func activityViewController(_ activityViewController: UIActivityViewController, subjectForActivityType activityType: UIActivityType?) -> String {
        return appName
    }
}

比按下分享按钮时你可以这样称呼它

 ShareMenu.open(
     text: "Can you beat my score?", 
     image: UIImage(...),  // set to nil if unused
     appStoreURL: "your iTunes app store URL",  // set to nil if unused
     from: view?.window?.rootViewController
 )

请记住，图像和 appStoreURL 不会随处显示，这取决于共享服务。

您还可以使用场景中的得分值并将其添加到文本中，例如

ShareMenu.open( 
     text: "Can you beat my score \(self.score)?",
     ...
)

希望对你有帮助

Answer 2

我不会进入SLComposeViewController相关代码。除了 crashoverride777 提出的方法之外，我将只向您展示两种技术。所以第一种技术是使用通知，像这样：

游戏场景：

import SpriteKit

let kNotificationName = "myNotificationName"

class GameScene: SKScene {


    private func postNotification(named name:String){

        NotificationCenter.default.post(
            Notification(name: Notification.Name(rawValue: name),
                         object: self,
                         userInfo: ["key":"value"]))
    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {


        self.postNotification(named: kNotificationName)

    }
}

在这里，您可以通过点击屏幕来发布通知。所需的视图控制器类可以监听此通知，如下所示：

import UIKit
import SpriteKit

class GameViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()


        NotificationCenter.default.addObserver(
            self,
            selector: #selector(self.handle(notification:)),
            name: NSNotification.Name(rawValue: kNotificationName),
            object: nil)

        if let view = self.view as! SKView? {
            // Load the SKScene from 'GameScene.sks'
            if let scene = GameScene(fileNamed: "GameScene") {
                // Set the scale mode to scale to fit the window
                scene.scaleMode = .aspectFill

                // Present the scene
                view.presentScene(scene)
            }
        }
    }

    func handle(notification:Notification){
        print("Notification : \(notification)")
    }
}

在这里，我们添加 self 作为该通知的观察者 - 意味着当通知发生时，将调用适当的处理方法（这是我们自定义的 handle(notification:) 方法。在该方法中，您应该调用您的代码：

if SLComposeViewController.isAvailable(forServiceType:   SLServiceTypeFacebook) {
     let fShare = SLComposeViewController(forServiceType: SLServiceTypeFacebook)
     self.presentViewController(fShare!, animated: true,  completion: nil)
}

其实，我会再写一个委托的例子，让事情保持干净:)

Answer 3

正如我所说，这可以使用通知来完成，例如 this answer，或者您可以使用委托：

首先您应该声明MyDelegate 协议，该协议定义了一个名为myMethod() 的方法。

 protocol MyDelegate:class {

        func myMethod()
    }

该方法是每个类都必须实现的要求，如果它符合此协议。

在我们的示例中，您可以将场景视为worker，将视图控制器视为boss。当场景完成其任务时，它会通知其老板（将职责委派给他）工作完成，以便老板决定下一步做什么。我的意思是，我可以说：“场景是一个老板，它将责任委托给他的员工，即视图控制器......”但你认为谁是老板并不重要......delegation pattern很重要.

所以，视图控制器，应该符合这个协议，它会实现myMethod()（稍后会被场景调用）：

class GameViewController: UIViewController, MyDelegate {

override func viewDidLoad() {
    super.viewDidLoad()

    //MARK: Conforming to MyDelegate protocol

    if let view = self.view as! SKView? {
        // Load the SKScene from 'GameScene.sks'
        if let scene = GameScene(fileNamed: "GameScene") {
            // Set the scale mode to scale to fit the window
            scene.scaleMode = .aspectFill

            scene.myDelegate = self

            // Present the scene
            view.presentScene(scene)
        }
    }
   }

func myMethod(){
    print("Do your stuff here")
}


 }

这是来自GameScene 的代码，您在其中定义了我们用来与视图控制器通信的myDelegate 属性：

import SpriteKit

class GameScene: SKScene {


   weak var myDelegate:MyDelegate?



override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {


    self.myDelegate?.myMethod()

    }
}

要了解何时选择委托而不是通知，反之亦然，请查看 this article（或者只是搜索 SO，有一些不错的帖子）。