使用 JavaScript 桥接访问原生 API

val myListener = WebViewCompat.WebMessageListener { _, _, _, _, replyProxy ->
    // Handle the message from JS
    replyProxy.postMessage("Acknowledged!")
}

// Check whether the WebView version supports the feature.
if (WebViewFeature.isFeatureSupported(WebViewFeature.WEB_MESSAGE_LISTENER)) {
    val allowedOrigins = setOf("https://www.example.com")
    WebViewCompat.addWebMessageListener(webView, "myObject", allowedOrigins, myListener)
}
NativeApiAccessJsbridge.kt

WebMessageListener myListener = (view, message, sourceOrigin, isMainFrame, replyProxy) -> {
    // Handle the message from JS
    replyProxy.postMessage("Acknowledged!");
};

// Check whether the WebView version supports the feature.
if (WebViewFeature.isFeatureSupported(WebViewFeature.WEB_MESSAGE_LISTENER)) {
    Set<String> allowedOrigins = Set.of("https://www.example.com");
    WebViewCompat.addWebMessageListener(webView, "myObject", allowedOrigins, myListener);
}

fun setupWebView(webView: WebView) {
    if (WebViewFeature.isFeatureSupported(WebViewFeature.WEB_MESSAGE_LISTENER)) {
        val listener = WebViewCompat.WebMessageListener { view, message, sourceOrigin, isMainFrame, replyProxy ->

            // Check if the received message is an ArrayBuffer
            if (message.type == WebMessageCompat.TYPE_ARRAY_BUFFER) {
                val binaryData: ByteArray = message.arrayBuffer
                // Process your binary data (image, audio, etc.)
                println("Received bytes: ${binaryData.size}")

                // Optional: Send a binary reply back to JavaScript.
                // This example sends a 3-byte array for simplicity.
                if (WebViewFeature.isFeatureSupported(WebViewFeature.WEB_MESSAGE_ARRAY_BUFFER)) {
                    val replyBytes = byteArrayOf(0x01, 0x02, 0x03)
                    replyProxy.postMessage(replyBytes)
                }
            }
        }

        // "myBridge" matches the window.myBridge in JavaScript
        WebViewCompat.addWebMessageListener(
            webView,
            "myBridge",
            setOf("https://example.com"), // Security: restrict origins
            listener
        )
    }
}
NativeApiAccessJsbridge.kt

public void setupWebView(WebView webView) {
  if (WebViewFeature.isFeatureSupported(WebViewFeature.WEB_MESSAGE_LISTENER)) {
      WebViewCompat.WebMessageListener listener = (view, message, sourceOrigin, isMainFrame, replyProxy) -> {

          // Check if the received message is an ArrayBuffer
          if (message.getType() == WebMessageCompat.TYPE_ARRAY_BUFFER) {
              byte[] binaryData = message.getArrayBuffer();
              // Process your binary data (image, audio, etc.)
              System.out.println("Received bytes: " + binaryData.length);

              // Optional: Send a binary reply back to JavaScript.
              // This example sends a 3-byte array for simplicity.
              if (WebViewFeature.isFeatureSupported(WebViewFeature.WEB_MESSAGE_ARRAY_BUFFER)) {
                  byte[] replyBytes = new byte[]{0x01, 0x02, 0x03};
                  replyProxy.postMessage(replyBytes);
              }
          }
      };

      // "myBridge" matches the window.myBridge in JavaScript
      WebViewCompat.addWebMessageListener(
          webView,
          "myBridge",
          Set.of("https://example.com"), // Security: restrict origins
          listener
      );
  }
}

webView.webViewClient = object : WebViewClient() {
    override fun shouldInterceptRequest(
        view: WebView?,
        request: WebResourceRequest?
    ): WebResourceResponse? {
        val url = request?.url ?: return null

        // Check if this is our custom placeholder URL
        if (url.host == "app.local" && url.path == "/data/large-file.bin") {
            try {
                // 1. Get your data as an InputStream
                // (from Assets, Files, or a generated byte stream)
                val inputStream: InputStream = context.assets.open("my_data.pb")

                // 2. Define Response Headers (Crucial for CORS/Fetch)
                val headers = mutableMapOf<String, String>()
                headers["Access-Control-Allow-Origin"] = "*" // Allow fetch from any origin

                // 3. Return the response
                return WebResourceResponse(
                    "application/octet-stream", // MIME type (for example, image/jpeg)
                    "UTF-8", // Encoding
                    200, // Status Code
                    "OK", // Reason Phrase
                    headers, // Custom Headers
                    inputStream // The actual data stream
                )
            } catch (e: Exception) {
                // Handle exception
            }
        }
        return super.shouldInterceptRequest(view, request)
    }
}
NativeApiAccessJsbridge.kt

webView.setWebViewClient(new WebViewClient() {
  @Override
  public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
      String urlPath = request.getUrl().getPath();
      String host = request.getUrl().getHost();

      // Check if this is our custom placeholder URL
      if ("app.local".equals(host) && "/data/large-file.bin".equals(urlPath)) {
          try {
              // 1. Get your data as an InputStream
              // (from Assets, Files, or a generated byte stream)
              InputStream inputStream = getContext().getAssets().open("my_data.pb");

              // 2. Define Response Headers (Crucial for CORS/Fetch)
              Map<String, String> headers = new HashMap<>();
              headers.put("Access-Control-Allow-Origin", "*"); // Allow fetch from any origin

              // 3. Return the response
              return new WebResourceResponse(
                  "application/octet-stream", // MIME type (for example, image/jpeg)
                  "UTF-8",                   // Encoding
                  200,                       // Status Code
                  "OK",                      // Reason Phrase
                  headers,                   // Custom Headers
                  inputStream                // The actual data stream
              );
          } catch (Exception e) {
              // Handle exception
          }
      }
      return super.shouldInterceptRequest(view, request);
  }
});