You have one base class virtual function how will you call from derieved class

public class Base
{
   public Base(){}
   public virtual void show(string message)
   {
      //Your Logic
   }
}

public class Derived
{
// Only if  you want to override base class show method
   public override void show(string message)
   {
      //Your Logic to override 
   }
}

public class CallFunction
{
    public static void Main()
    {
       Derived obj = new Derived()
       obj.show("Hii");
    }
}