https://learn.microsoft.com/en-us/dotnet/api/system.windows.frameworkcontentelement.tryfindresource?view=netframework-4.8.1&viewFallbackFrom=windowsdesktop-10.0
FrameworkContentElement.TryFindResource(Object) Method (System.Windows) | Microsoft Learn
Searches for a resource with the specified key, and returns that resource if found.
objectmethodsystemwindowsmicrosoft