How to: Inherit from a Generic Type
You can use Class Designer to create a type that inherits from a generic type.
By using Class Designer, you can visualize existing generic types, but you cannot create new generic types. You also cannot modify type parameters on existing generic types.
To inherit from a generic type
In the Toolbox, select the Inheritance line.
In the class diagram, draw an inheritance line from the derived type to the base type. (In this procedure, the base type is a generic type.)
An inheritance line pointing from the derived type to the base type appears on the design surface. The inheritance line obtains focus and its properties display in the Properties window.
In the Properties window, the Type Arguments property displays default values for the inheritance line. Change the value of the Type Arguments property to match the desired types for the derived type.