Microsoft.Toolkit.Win32 | repository contains all controls for WPF and WinForms | Form library

Finally I found the solution. Add these lines to the initialization code:

It seems to be a known issue with WebView control in WindowsCommunityToolkit

• You can use only absolute URIs to resources in members of the WebView control that accept string paths.
• WebView controls don't recognize the ms-appx:/// prefix, so they can't read from the package (if you've created a package for your application).
• WebView controls don't recognize the File:// prefix. If you want to read a file into a WebView control, add code to your application that reads the content of the file. Then, serialize that content into a string, and call the NavigateToString(String) method of the WebView control.

So, instead of loading a file this.wv.Source = new Uri("ms-appx-web://Assets/index.html"); try to read a local file and then navigate to the string

HTTPS link worked fine for me, maybe the page is too slow to load?

According to Microsoft (source), only ScriptNotify is supported in WebView:

Can I inject native objects into my WebViewControl content?

No. Neither the WebBrower (Internet Explorer) ObjectForScripting property nor the WebView (UWP) AddWebAllowedObject method are supported in WebViewControl. As a workaround, you can use window.external.notify/ ScriptNotify and JavaScript execution to communicate between the layers, for example: https://github.com/rjmurillo/WebView_AddAllowedWebObjectWorkaround

But the above suggested workaround solution seems to work differently to your expectation, so I just implement my own solution to emulate the JSBridge convention you have expected.

My custom solution is not battle-tested, it might break in some edge cases but it seems to work fine in few simple tests.

What's supported:

• Multiple bridge objects
• JS to C# method call
• JS to C# get/set property

C# Usage:

C++/WinRT 2.0 introduced a breaking change in order to support Optimized Components. It is used when passing -optimize to cppwinrt.exe. This option is enabled by default for new projects.

The breaking change requires component authors to #include a generated implementation file into the compilation unit that implements that particular type. In your case, you need to #include "App.g.cpp" into App.cpp (make sure to #include it after the header file App.h).

To allow your code to compile with and without the -optimize flag, you can conditionally include App.g.cpp: