SwiftUI：Javascript 与 macOS 上的 WKWebView 通信

Question

我希望 javascript 将消息发送回我的 WKWebView 对象，但我没有收到任何响应。我知道脚本是运行ning，随着颜色的变化，但我希望也能在控制台中看到打印的“来自 JS 的触发器”，但我没有看到。如果我运行 Chrome 中的 html，javascript 控制台会显示“无法读取未定义的属性 'messageHandlers'”。如果我为 iOS 构建（使用 UIViewRepresentable、MakeUIView 和 UpdateUIView），结果是相同的。如果有人能发现我遗漏的内容，我将不胜感激。

这是完整的代码：

import SwiftUI
import WebKit

class HtmlData {
    let html = """
    <!DOCTYPE html>
    <html>
    <body>

    <button onclick="sendMessage()">Send Message</button>
    <script>
    function sendMessage() {
      document.body.style.backgroundColor = "red";
     window.webkit.messageHandlers.testMessage.postMessage("trigger from JS");
    }
    </script>
    </body>
    </html>
    """
}

struct ContentView: View {
    let htmlData = HtmlData()
    var body: some View {
        JSWebView(html: htmlData.html)
    }
}

struct JSWebView: NSViewRepresentable {
    let html: String
    func makeNSView(context: Context) -> WKWebView {
        let preferences = WKPreferences()
        preferences.javaScriptEnabled = true
        return WKWebView()
    }
    
    func updateNSView(_ view: WKWebView, context: Context) {
        let userContentController = WKUserContentController()
        let handler = ContentController(view)
        let configuration = WKWebViewConfiguration()
        configuration.userContentController = userContentController
        configuration.userContentController.add(handler, name: "testMessage")
        view.loadHTMLString(html, baseURL: Bundle.main.bundleURL)
    }
    
    class ContentController: NSObject, WKScriptMessageHandler {
        var parent: WKWebView?
        init(_ parent: WKWebView?) {
            self.parent = parent
        }
        func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
            print(message.body)
        }
    }
}

Answer 1

必须将配置传递到 WKWebView 的构造函数中。初始化后无法设置

struct JSWebView: NSViewRepresentable {
    let html: String
    
    func makeNSView(context: Context) -> WKWebView {
        let preferences = WKPreferences()
        preferences.javaScriptEnabled = true
        let handler = MessageHandler()
        let configuration = WKWebViewConfiguration()
        configuration.userContentController.add(handler, name: "testMessage")
        return WKWebView(frame: .zero, configuration: configuration)
    }
    
    func updateNSView(_ view: WKWebView, context: Context) {
        view.loadHTMLString(html, baseURL: Bundle.main.bundleURL)
    }
    
    class MessageHandler: NSObject, WKScriptMessageHandler {
        func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
            print(message.body)
        }
    }
}

SwiftUI：Javascript 与 macOS 上的 WKWebView 通信

SwiftUI: Javascript communication with WKWebView on macOS

javascript

swiftui

webkit

wkwebview