具有枚举类型的泛型类型

Question

I'm writing code for parameter class that being used by some kind of commands. This command has two main Issues:

• OptionalValues - This is the optional values to be selected.
• SelectedValue - The user choice.

The user input is: select one member from enum.

The code:

public enum eUserChoice
{
    Choice1,
    Choice2,
    Choice3
};

public class Parameter<ENUM_TYPE>
{
    public ENUM_TYPE OptionalValues {get;} // WRONG USING
    public ENUM_TYPE Value {get; set;}
}

Requested behavior of the code:

Parameter<eUserChoice> myParam = new Parameter<eUserChoice>()
myParam.Value = myParam.OptionalValues.Choice1;
// OR:
// myParam.Value = myParam.OptionalValues.Choice1 | myParam.OptionalValues.Choice2;

When I'm writing "myParam.OptionalValues." I'm want that this will be equal to write "eUserChoice." ( intellisense is important).

I'm not sure if it's possible... What do you think?

Answer 1

Generics are not (that) magic. With the following line

public ENUM_TYPE OptionalValues {get;}

You are creating a property that can have a value of type ENUM_TYPE. However what you want is to let the OptionalValues property link to the type itself. This is impossible.

Generics simply allow you to create some sort of class template (c++ people: not that kind of template) which generates a new class for each type of ENUM_TYPE you supply. And nothing more.