Question

我目前正在开发一个集成了Facebook的iOS应用程序，我在使用Swift进行调查时遇到了一些问题（使用ObjC我没有问题）。

问题是，当来自另一个APP（在这种情况下是WebBrowser中的FB）时，这是在appDelegate中执行的方法：

func application(
    application: UIApplication,
    openURL url: NSURL,
    sourceApplication: NSString,
    annotation: AnyObject)
    -> Bool { 
       let appString : String = sourceApplication as String // Try to convert format => EXCEPTION
       let appString : String = String(sourceApplication)   // 'SSS' Suggestion: EXCEPTION
       println(sourceApplication) // Try to print the value => EXCEPTION
       return FBAppCall.handleOpenURL(url, sourceApplication:sourceApplication,
            withSession:session) // With Parse => EXCEPTION
}

在该方法中，我遇到了'sourceApplication'参数的问题。我尝试使用它，我得到一个例外。我尝试转换它，另一个例外...甚至无法记录其值，因为它在访问其值时崩溃。将函数签名中的参数类型更改为String既不起作用。

这是我得到的错误：

EXEC_BAD_ACCESS

我已经能够追踪，直到我能读到它，这绝对是一个有价值的暗示：

ObjectiveC.NSString.__conversion (ObjectiveC.NSString)() -> Swift.String

这可能是iOS8的错误吗？你们中的任何人都有这个问题和/或知道如何解决它？

Answer 1

你犯了两个错误：

app Delegate的函数声明为func application(application: UIApplication!, openURL url: NSURL!, sourceApplication: String!, annotation: AnyObject!) -> Bool：sourceApplication是一个可选的String值，而不是NSString。
由于sourceApplication是可选的，因此可能会返回 nil 值（在您的情况下返回 nil ）。键入 nil 到字符串是不安全的，因此它会崩溃。

解决方案：

在您的案例中不需要类型转换因为返回的值是字符串类型
使用可选的表单类型强制转换操作符作为？来安全地键入强制转换，即

if let appString = sourceApplication { println(appString as? String) }

Answer 2

这对我有用（使用FacebookSDK）：

func application(application: UIApplication, openURL url: NSURL, sourceApplication: NSString?, annotation: AnyObject) -> Bool {
    var wasHandled:Bool = FBAppCall.handleOpenURL(url, sourceApplication: sourceApplication)
    return wasHandled
}

Answer 3

我不会在操场上看到这个。可能是你建议的iOS 8错误但是为了尝试，你可以试试

let appString : String = String(sourceApplication)

Answer 4

对于FB Messenger ，这是我在AppDelegate中更好地处理的方法。大多数想法都直接来自FB IOS documentation并移植到Swift。

为什么我觉得我应该写一个额外的回复？我有一些使用Swift的经验，但感觉我浪费了足够的时间试图获得正确的代码来做我的事情FB Messenger需要。希望原始代码对某人有用，只需要整合大量的零碎并节省一些时间。

注意：这不包括您想要/需要的所有AppDelegate生命周期方法，但希望它是一个良好的开端

@UIApplicationMain class AppDelegate: UIResponder, UIApplicationDelegate, FBSDKMessengerURLHandlerDelegate {

var window: UIWindow?
var messengerUrlHandler: FBSDKMessengerURLHandler?
var cancelContext : FBSDKMessengerURLHandlerCancelContext?
var composerContext : FBSDKMessengerURLHandlerOpenFromComposerContext?
var replyContext: FBSDKMessengerURLHandlerReplyContext?

// Facebook Messenger
enum MessengerShareMode : Int {
    case MessengerShareModeCancel
    case MessengerShareModeSend
    case MessengerShareModeComposer
    case MessengerShareModeReply
}

// shareMode holds state indicating which flow the user is in.
// Return the corresponding FBSDKMessengerContext based on that state.
var shareMode : MessengerShareMode?

/*
* Initialize the FB messenger handler and set self as the delegate.
*/
func application(application: UIApplication, willFinishLaunchingWithOptions launchOptions: [NSObject : AnyObject]?) -> Bool {
    YARAppearance.setAppearance()

    let rootController = TabBarController()
    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
    self.window!.rootViewController = rootController
    self.window!.makeKeyAndVisible()

    // Facebook messenger handling
    self.messengerUrlHandler = FBSDKMessengerURLHandler()
    if (self.messengerUrlHandler != nil) {
        self.messengerUrlHandler!.delegate = self
    }
    return true
}

/*
* Handle the cancel context flow.
*/
func messengerURLHandler(messengerURLHandler: FBSDKMessengerURLHandler!,
    didHandleCancelWithContext context: FBSDKMessengerURLHandlerCancelContext!) {
        self.cancelContext = context
        self.shareMode = .MessengerShareModeCancel
}

/*
* When people enter your app through the composer in Messenger,
* this delegate function will be called.
*/
func messengerURLHandler(messengerURLHandler: FBSDKMessengerURLHandler!,
    didHandleOpenFromComposerWithContext context: FBSDKMessengerURLHandlerOpenFromComposerContext!) {
        self.composerContext = context
        self.shareMode = .MessengerShareModeComposer
}

/*
* When people enter your app through the "Reply" button on content
* this delegate function will be called.
*/
func messengerURLHandler(messengerURLHandler: FBSDKMessengerURLHandler!,
    didHandleReplyWithContext context: FBSDKMessengerURLHandlerReplyContext!) {
    self.replyContext = context
    self.shareMode = .MessengerShareModeReply
}

/*
* Handle URL calls from external applications, particularly Messenger
*/
func application(application: UIApplication, openURL url: NSURL, sourceApplication: String?, annotation: AnyObject) -> Bool {
    let wasHandled:Bool = self.messengerUrlHandler!.openURL(url, sourceApplication: sourceApplication)
    return wasHandled
}

/*
* A way to access the context objects elsewhere
*/
func getContextForShareMode() -> FBSDKMessengerContext? {
    // shareMode holds state indicating which flow the user is in.
    // Return the corresponding FBSDKMessengerContext based on that state.
    if (shareMode == .MessengerShareModeSend) {
        // Force a send flow by returning a broadcast context.
        return FBSDKMessengerBroadcastContext()

    } else if (shareMode == .MessengerShareModeComposer) {
        // Force the composer flow by returning the composer context.
        return self.composerContext!

    } else if (shareMode == .MessengerShareModeReply) {
        // Force the reply flow by returning the reply context.
        return self.replyContext!
    }
    return nil
}
}

APP中的openURL转换错误NSString - ＆gt;字符串（Swift＆amp; iOS8）

4 个答案: