当通过 macOS 本机应用程序内的 SwiftUI WKWebView 调用时，如何让文件打开对话框工作？

Question

我目前正在运行一个用 SwiftUI 制作的简单 WkWebView - 包含我能够从这篇 StackOverflow 帖子中看到的所有建议。它打开一个网站。该网站有一个浏览器按钮。如果我单击 Safari 上的浏览​​器按钮，则会打开一个 Finder 窗口。如果我在用 Xcode 创建的 .app 中做同样的事情，Finder 窗口不会打开。

这是我在沙箱中启用的东西：

我使用的代码是这样的（全部来自 ContentView.swift）

import SwiftUI
import WebKit


public struct WebBrowserView {

    private let webView: WKWebView = WKWebView()

    // ...

    public func load(url: URL) {
        webView.load(URLRequest(url: url))
    }

    public class Coordinator: NSObject, WKNavigationDelegate, WKUIDelegate {

        var parent: WebBrowserView

        init(parent: WebBrowserView) {
            self.parent = parent
        }

        public func webView(_: WKWebView, didFail: WKNavigation!, withError: Error) {
            // ...
        }

        public func webView(_: WKWebView, didFailProvisionalNavigation: WKNavigation!, withError: Error) {
            // ...
        }

        public func webView(_: WKWebView, didFinish: WKNavigation!) {
            // ...
        }

        public func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
            // ...
        }

        public func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
            decisionHandler(.allow)
        }

        public func webView(_ webView: WKWebView, createWebViewWith configuration: WKWebViewConfiguration, for navigationAction: WKNavigationAction, windowFeatures: WKWindowFeatures) -> WKWebView? {
            if navigationAction.targetFrame == nil {
                webView.load(navigationAction.request)
            }
            return nil
        }
    }

    public func makeCoordinator() -> Coordinator {
        Coordinator(parent: self)
    }
}


#if os(macOS) // macOS Implementation (iOS version omitted for brevity)
extension WebBrowserView: NSViewRepresentable {

    public typealias NSViewType = WKWebView

    public func makeNSView(context: NSViewRepresentableContext<WebBrowserView>) -> WKWebView {

        webView.navigationDelegate = context.coordinator
        webView.uiDelegate = context.coordinator
        return webView
    }

    public func updateNSView(_ nsView: WKWebView, context: NSViewRepresentableContext<WebBrowserView>) {

    }
}
#endif

struct BrowserView: View {

    private let browser = WebBrowserView()

    var body: some View {
        HStack {
            browser
                .onAppear() {
                    self.browser.load(url: URL(string: "http://specificwebsitewithbrowserbutton")!)
                }
        }
        .padding()
    }
}


struct ContentView: View {

    @State private var selection = 1

    var body: some View {
                BrowserView()
                .frame(maxWidth: .infinity, maxHeight: .infinity)
    }
}

那么，如何给这个 .app 足够的权限，以便在我点击网站上的“上传”按钮时打开 Finder 窗口？

Answer 1

您必须实现以下WKUIDelegate委托方法

   /** @abstract Displays a file upload panel.
     @param webView The web view invoking the delegate method.
     @param parameters Parameters describing the file upload control.
     @param frame Information about the frame whose file upload control initiated this call.
     @param completionHandler The completion handler to call after open panel has been dismissed. Pass the selected URLs if the user chose OK, otherwise nil.

     If you do not implement this method, the web view will behave as if the user selected the Cancel button.
     */
    @available(OSX 10.12, *)
    optional func webView(_ webView: WKWebView, runOpenPanelWith 
                  parameters: WKOpenPanelParameters, initiatedByFrame frame: WKFrameInfo, 
                  completionHandler: @escaping ([URL]?) -> Void)

这是实现示例

func webView(_ webView: WKWebView, runOpenPanelWith parameters: WKOpenPanelParameters, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping ([URL]?) -> Void) {
    let openPanel = NSOpenPanel()
    openPanel.canChooseFiles = true
    openPanel.begin { (result) in
        if result == NSApplication.ModalResponse.OK {
            if let url = openPanel.url {
                completionHandler([url])
            }
        } else if result == NSApplication.ModalResponse.cancel {
            completionHandler(nil)
        }
    }
}