https://learn.microsoft.com/zh-cn/dotnet/api/system.componentmodel.design.serialization.designerloader?view=netframework-4.8.1&viewFallbackFrom=net-10.0
DesignerLoader Class (System.ComponentModel.Design.Serialization) | Microsoft Learn
Provides a basic designer loader interface that can be used to implement a custom designer loader.
class systemdesignserializationmicrosoftlearn