Up casting - c#

Question

public class a{
  public string x1 {get;set;}
  public string x2 {get;set;}
  public string x3 {get;set;}
}

public class b:a{
}

Obviously v

Answer 1

You can't make that cast.

You can, and I guess you should, use an interface.

public interface ia
{
    string x1 { get; set; }
    string x2 { get; set; }
    string x3 { get; set; }
}
public class a : ia
{
    public string x1 { get; set; }
    public string x2 { get; set; }
    public string x3 { get; set; }
}

public class b : a, ia
{
}

Then you can

ia foo = new a();