Ios中的js交互

import WebKit

class ViewController: UIViewController {
    var webView: WKWebView!

    override func viewDidLoad() {
        super.viewDidLoad()

        // 创建WKWebView配置
        let webConfiguration = WKWebViewConfiguration()

        // 初始化WKWebView
        webView = WKWebView(frame: .zero, configuration: webConfiguration)
        webView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(webView)

        // 添加约束
        NSLayoutConstraint.activate([
            webView.topAnchor.constraint(equalTo: view.topAnchor),
            webView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
            webView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            webView.trailingAnchor.constraint(equalTo: view.trailingAnchor)
        ])

        // 加载网页内容
        if let url = URL(string: "https://www.example.com") {
            let request = URLRequest(url: url)
            webView.load(request)
        }
    }
}

// 在JavaScript中定义一个函数，用于与原生代码交互
// JavaScript代码示例：<script>
//     function showAlert(message) {
//         window.webkit.messageHandlers.nativeApp.postMessage(message);
//     }
// </script>

// 在原生代码中添加JavaScript接口
let contentController = WKUserContentController()
contentController.add(self, name: "nativeApp")

let webConfiguration = WKWebViewConfiguration()
webConfiguration.userContentController = contentController

webView = WKWebView(frame: .zero, configuration: webConfiguration)

// 实现WKScriptMessageHandler协议，处理来自JavaScript的消息
extension ViewController: WKScriptMessageHandler {
    func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
        if message.name == "nativeApp", let messageBody = message.body as? String {
            // 处理来自JavaScript的消息
            print("Received message from JavaScript: \(messageBody)")
        }
    }
}