Kii Kii - 3 months ago 13
C# Question

Use reflection to invoke an overridden base method

How to use reflection call a base method that is overridden by derived class?

class Base
{
public virtual void Foo() { Console.WriteLine("Base"); }
}
class Derived : Base
{
public override void Foo() { Console.WriteLine("Derived"); }
}
public static void Main()
{
Derived d = new Derived();
typeof(Base).GetMethod("Foo").Invoke(d, null);
Console.ReadLine();
}


This code always shows 'Derived'...

Answer

You can't do that, even with reflection. Polymorphism in C# actually guarantees that Derived.Foo() will always be called, even on an instance of Derived cast back to its base class.

The only way to call Base.Foo() from a Derived instance is to explicitly make it accessible from the Derived class:

class Derived : Base
{
    public override void Foo()
    {
        Console.WriteLine("Derived");
    }

    public void BaseFoo()
    {
        base.Foo();
    }
}
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