Overriding constants in derived classes in C#

It’s not a constant if you want to override it ;). Try a virtual read-only property (or protected setter).

Read-only property:

public class MyClass {
    public virtual string MyConst { get { return "SOMETHING"; } }
}
...
public class MyDerived : MyClass {
    public override string MyConst { get { return "SOMETHINGELSE"; } }
}

Protected setter:

public class MyClass {
    public string MyConst { get; protected set; }

    public MyClass() {
        MyConst = "SOMETHING";
    }
}

public class MyDerived : MyClass {
    public MyDerived() {
        MyConst = "SOMETHING ELSE";
    }
}