What's wrong with interface inheritance?

Question

.NET

I'm learning about interface inheritance. When compiling this code:

using System;
 
public class Test
{
  public static void Main()
  {
    Lol l = new Lol();
    Console.WriteLine(((IParent)l).Family);
    Console.WriteLine(((IChild)l).Family);
    Console.WriteLine(l.Name);
  }
}
 
public interface IParent
{
  string Family { get; }
}
 
public interface IChild : IParent
{
  string Name { get; }
}
 
public class Lol : IChild
{
  string IParent.Family { get { return "suck"; } }
  string IChild.Family { get { return "duck"; } }
  public string Name { get { return "ross"; } }
}

IdeOne throws:
prog.cs(27,26): error CS0550: `Lol.IChild.Family.get' is an accessor not found in interface member `IChild.Family'

Compilation failed: 1 error(s), 0 warnings mistake?

Answer 1

You didn't specify that Lol implements the IParent interface
. Also, you probably wanted to add a Family property to IChild.
After updating the code:
You are using an explicit implementation of the interface, but IChild does not have its own Family property, only inherited from IParent. You can just learn the new keyword from properties.
Perhaps what you want to see is done like this:

using System;


public class Test
{
  public static void Main()
  {
    Lol l = new Lol();
    Console.WriteLine(((IParent)l).Family);
    Console.WriteLine(((IChild)l).Family);
    Console.WriteLine(l.Name);
    Console.ReadLine ();
  }
}

public class IParent
{
  public string Family { get { return "suck"; } }
}

public class IChild : IParent
{
  public string Family { get { return "duck"; } }

}

public class Lol : IChild
{	
  public string Name { get { return "ross"; } }
}
// Вывод:
// suck
// duck
// ross

Answer 2

public class Lol : IChild,    IParent  // !!!
{
  string IParent.Family { get { return "suck"; } }
  string IChild.Family { get { return "duck"; } }
  public string Name { get { return "ross"; } }
}

You are trying to use an interface property without inheriting it.
I advise you to learn English or at least learn to read errors.

Answer 3

There is a small exception when you explicitly implement interfaces, C# expects you to specify derived interface names, not interface names that might be inherited from another interface.
In your case, IChild does not contain a Family field, which is why you get the 'accessor not found' error.
The essence of the explicit interface implementation is the explicit use of interface names, without regard to the base interface.
You can do the following.

public interface IChild : IParent
    {
        new string Family { get; }
        string Name { get; }
    }

Although this is hardly what you expected to hear, but here are the restrictions ((
I apologize if I confused.