The new Unity WebView2 control creates and uses C++ COM to create and manage the ICoreWebView2* objects. However, Unity developers are often interacting with the Unity WebView2 control using C#/.NET. The Unity WebView2 control doesn't expose the CoreWebView2 directly to devs using the Unity WebView2 control, so when devs want to call an API on CoreWebView2, they have to rely on that API being exposed on the Unity WebView2 control, which then internally calls into CoreWebView2. This is in contrast to our other controls (like WPF WebView2 and Winforms WebView2 controls) which directly give access to their CoreWebView2 object, allowing devs to call any API that exists or gets added to the CoreWebView2/ICoreWebView2_*. The Unity WebView2 control can't do this today, as they are unable to create a CoreWebView2 object that wraps an already existing COM object. To help implement this for Unity, we are adding a new static factory function on CoreWebView2 .NET class that will allow it to wrap an existing ICoreWebView2 COM object, instead of creating a new one.
public class MyWebView2Control
{
... // Regular control code
CoreWebView2 _myCoreWebView2 = null;
[DllImport(DLL_NAME, CallingConvention = CallingConvention.StdCall)]
public static extern ComNativePointer GetNativePointer(WebViewInstancePtr instanceId);
// This is the CoreWebView2 property which allows developers to access CoreWebView2 APIs directly.
public CoreWebView2 CoreWebView2
{
get
{
if (!_myCoreWebView2)
{
IntPtr comPtr = WebViewNative.GetNativePointer(InstanceId);
_myCoreWebView2 = CoreWebView2.CreateFromComICoreWebView2(comPtr);
}
return _myCoreWebView2;
}
}
}namespace Microsoft.Web.WebView2.Core
{
public class CoreWebView2
{
/// <summary>
/// Creates a CoreWebView2 object that wraps an existing COM ICoreWebView2 object.
/// This allows interacting with the WebView2 control using .NET,
/// even if the control was originally created using COM.
/// </summary>
/// <param name="value">Pointer to a COM object that implements the ICoreWebView2 COM interface.</param>
/// <returns>Returns a .NET CoreWebView2 object that wraps the COM object.</returns>
/// <exception cref="ArgumentNullException">Thrown when the provided COM pointer is null.</exception>
/// <exception cref="InvalidComObjectException">Thrown when the value is not an ICoreWebView2 COM object and cannot be wrapped.</exception>
public static CoreWebView2 CreateFromComICoreWebView2(IntPtr value);
}
}We have a couple of other options to accomplish this, including moving the "CreateFromComICoreWebView2" function to the CoreWebView2Controller class instead. CoreWebView2Controller could then be used to get the CoreWebView2 through its CoreWebView2 property which already exists. Or we could expose a new constructor on CoreWebView2/CoreWebView2Controller, instead of a factory method.
We decided on using the CoreWebView2 due to it being the class most likely to be exposed and used in .NET, and which is the same across different C# frameworks. We decided on a factory method to not give the impression that a new constructor is the default one (we don't currently have any public constructors), and to make the intent and usage of the method more obvious.