How to call platform-specific APIs?

3D WebView's IWebView interface is implemented by a different class on each platform:

In addition to implementing IWebView, these classes also include extra platform-specific methods. As demonstrated below, an application can call a platform-specific static method by accessing it directly on the class, and it can call a platform-specific instance method by casting an IWebView instance to the specific class.

Windows and macOS

The StandaloneWebView class is available when running in the editor and building for Standalone Windows or macOS. So, an #if directive usually isn't needed in order to reference it:

StandaloneWebView.EnableRemoteDebugging(8080);

await webViewPrefab.WaitUntilInitialized();
var standaloneWebView = webViewPrefab.WebView as StandaloneWebView;
standaloneWebView.SetNativeFileDialogEnabled(true);

However, if you build your app for other platforms (e.g. Android, iOS, WebGL, or UWP), then you'll need to use the directive #if UNITY_STANDALONE || UNITY_EDITOR to prevent StandaloneWebView from being referenced on those other platforms:

#if UNITY_STANDALONE || UNITY_EDITOR
    StandaloneWebView.EnableRemoteDebugging(8080);
#endif

#if UNITY_STANDALONE || UNITY_EDITOR
    await webViewPrefab.WaitUntilInitialized();
    var standaloneWebView = webViewPrefab.WebView as StandaloneWebView;
    standaloneWebView.SetNativeFileDialogEnabled(true);
#endif

Android

The AndroidWebView and AndroidGeckoWebView classes are only accessible when building for an Android device, so it's necessary to use the directive #if UNITY_ANDROID && !UNITY_EDITOR in order to reference them. Here are examples of calling those classes' static methods:

#if UNITY_ANDROID && !UNITY_EDITOR
    AndroidWebView.SetGeolocationEnabled(true);
#endif

#if UNITY_ANDROID && !UNITY_EDITOR
    AndroidGeckoWebView.SetDrmEnabled(true);
#endif

And here are examples of calling their instance methods:

#if UNITY_ANDROID && !UNITY_EDITOR
    await webViewPrefab.WaitUntilInitialized();
    var androidWebView = webViewPrefab.WebView as AndroidWebView;
    androidWebView.Pause();
#endif

#if UNITY_ANDROID && !UNITY_EDITOR
    await webViewPrefab.WaitUntilInitialized();
    var androidGeckoWebView = webViewPrefab.WebView as AndroidGeckoWebView;
    androidGeckoWebView.SetSurface(surface);
#endif

iOS

The iOSWebView class is only accessible when building for an iOS device, so it's necessary to use the directive #if UNITY_IOS && !UNITY_EDITOR in order to reference it. Here's an example of calling one of its static methods:

#if UNITY_IOS && !UNITY_EDITOR
    iOSWebView.SetAllowsInlineMediaPlayback(false);
#endif

And here's an example of calling one of its instance methods:

#if UNITY_IOS && !UNITY_EDITOR
    await webViewPrefab.WaitUntilInitialized();
    var iOSWebViewInstance = webViewPrefab.WebView as iOSWebView;
    iOSWebViewInstance.SetScrollViewBounces(true);
#endif

visionOS

The VisionOSWebView class is only accessible when building for a visionOS device, so it's necessary to use the directive #if UNITY_VISIONOS && !UNITY_EDITOR in order to reference it. Here's an example of calling one of its static methods:

#if UNITY_VISIONOS && !UNITY_EDITOR
    VisionOSWebView.SetCameraEnabled(true);
#endif

And here's an example of calling one of its instance methods:

await webViewPrefab.WaitUntilInitialized();
#if UNITY_VISIONOS && !UNITY_EDITOR
    var visionOSWebView = webViewPrefab.WebView as VisionOSWebView;
    visionOSWebView.SetTargetFrameRate(15);
#endif

UWP

The UwpWebView class is only accessible when building for Universal Windows Platform, so it's necessary to use the directive #if UNITY_WSA && !UNITY_EDITOR in order to reference it. Here's an example of calling one of its static methods:

#if UNITY_WSA && !UNITY_EDITOR
    UwpWebView.SetGeolocationEnabled(true);
#endif

WebGL

The WebGLWebView class is only accessible when building for an WebGL, so it's necessary to use the directive #if UNITY_WEBGL && !UNITY_EDITOR in order to reference it. Here's an example of calling one of its static methods:

#if UNITY_WEBGL && !UNITY_EDITOR
    // Gets the Unity app's web page title.
    var title = WebGLWebView.ExecuteJavaScriptLocally("document.title");
    Debug.Log("Title: " + title);
#endif

And here's an example of calling one of its instance methods:

#if UNITY_WEBGL && !UNITY_EDITOR
    await canvasWebViewPrefab.WaitUntilInitialized();
    var webGLWebView = canvasWebViewPrefab.WebView as WebGLWebView;
    if (webGLWebView.CanAccessIFrameContent()) {
        Debug.Log("The iframe content can be accessed 👍");
    }
#endif