webview js 返回值

// 创建一个JavaScript接口类
public class WebAppInterface {
    Context mContext;

    /** Instantiate the interface and set the context */
    WebAppInterface(Context c) {
        mContext = c;
    }

    /** Show a toast from the web page */
    @JavascriptInterface
    public void showToast(String toast) {
        Toast.makeText(mContext, toast, Toast.LENGTH_SHORT).show();
    }
}

// 在Activity中添加JavaScript接口
WebView webView = (WebView) findViewById(R.id.webview);
webView.getSettings().setJavaScriptEnabled(true);
webView.addJavascriptInterface(new WebAppInterface(this), "Android");
webView.loadUrl("http://example.com");

// 在网页中的JavaScript代码
function showAndroidToast(toast) {
    Android.showToast(toast);
}

import WebKit

class ViewController: UIViewController, WKScriptMessageHandler {
    var webView: WKWebView!

    override func viewDidLoad() {
        super.viewDidLoad()

        let contentController = WKUserContentController()
        contentController.add(self, name: "nativeApp")

        let config = WKWebViewConfiguration()
        config.userContentController = contentController

        webView = WKWebView(frame: self.view.frame, configuration: config)
        self.view.addSubview(webView)

        if let url = URL(string: "http://example.com") {
            webView.load(URLRequest(url: url))
        }
    }

    func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
        if message.name == "nativeApp", let messageBody = message.body as? String {
            print("Received message from JavaScript: \(messageBody)")
        }
    }
}

// 在网页中的JavaScript代码
window.webkit.messageHandlers.nativeApp.postMessage("Hello from JavaScript!");