XCode11 错误“open(_:options:completionHandler:) 在应用程序扩展中不可用”

启动后触摸图 v1.0 https://apps.apple.com/us/app/touchgram-for-imessage/id1447336478?ls=1，这是 99% iMessage 应用程序扩展，我尝试更新到 XCode 11。

我开始收到错误open(_:options:completionHandler:) is unavailable in application extensions

我确认即使在琐碎的样本 https://github.com/AndyDentFree/im-plausibilities/tree/master/webFromIM/webFromIM%20MessagesExtension尝试从 iMessage 应用程序启动 Web URL：

For example https://github.com/AndyDentFree/im-plausibilities/blob/896219d07fa630f8ad960bc05ee0e9fcac76bb22/webFromIM/webFromIM%20MessagesExtension/MessagesViewController.swift#L117:

    let openSel = #selector(UIApplication.open(_:options:completionHandler:))
    while (responder != nil){
        if responder?.responds(to: openSel ) == true {
            // cannot package up multiple args to openSel 
            // so we explicitly call it on the iMessage application instance

            // found by iterating up the chain
            (responder as? UIApplication)?.open(url, completionHandler:handler) 
            return
        }
        responder = responder!.next
    }

2020年更新

下面是我自己对这个问题的回答，详细介绍了解决方法的工作原理。请注意，上面链接的示例已修复为既使用此解决方法，又显示在WKWebView在 iMessage 扩展本身内部。

如（唯一）中所述issue https://github.com/AndyDentFree/im-plausibilities/issues/2在该样本上，这是一个iOS 13 中的有意更改由 DTS 确认。我相信这是打击键盘扩展中滥用行为的一部分，该行为的副作用是 iMessage 扩展。

我已经想出了一个解决方法，与他们建议的相同。

1. 使用以下命令将 URL 转发到您的父应用程序self.extensionContext?.open
2. 让父应用程序启动您的外部应用程序或 URL 代表。

这是 Touchgram 的完整工作扩展

// UIViewController+iMessageContext.swift
// applied to class MessagesViewController: MSMessagesAppViewController, UrlOpeningInIMessage 

protocol UrlOpeningInIMessage {
    func openFromiMessageContext(url:URL)
}


extension UrlOpeningInIMessage where Self:UIViewController {
    func openFromiMessageContext(url:URL) {
        let handler = { (success:Bool) -> () in
            if success {
                os_log("Finished opening URL", log:tgEnv.logImUI, type:.debug)
            } else {
                os_log("Failed to open URL", log:tgEnv.logImUI, type:.debug)
            }
        }
        // logic same as onLaunchMainPressed, since XCode11 unable to compile extension using UIApplication.open
        // so we pass the URL through to the parent app to launch on our behalf
        let appName = Bundle.appName()
        let encodedUrl = url.dataRepresentation.base64EncodedString()
        guard let appUrl: URL = URL(string: "\(appName)://?url=\(encodedUrl)") else { return }
        // can only open our app, not generalised URLs
        self.extensionContext?.open(appUrl, completionHandler: handler)
    }
}