What are some good alternatives to multiple-inheritance in .NET?

Question

I\'ve run into a bit of a problem with my class hierarchy, in a WPF application. It\'s one of those issues where you have two inheritance trees merging together, and you can

Answer 1

One approach is to use extension methods with an interface to provide your "derived class" implementation, much like System.Linq.Queryable:

interface ICustomizableObject
{
    string SomeProperty { get; }
}

public static class CustomizableObject
{
    public static string GetXamlHeader(this ICustomizableObject obj)
    {
        return DoSomethingWith(obj.SomeProperty);
    }

    // etc
}

public class CustomizableControl : System.Windows.Controls.UserControl, ICustomizableObject
{
    public string SomeProperty { get { return "Whatever"; } }
}

Usage: As long as you have a using directive for (or are in the same namespace as) the namespace where your extension methods are defined:

var cc = new CustomizableControl();
var header = cc.GetXamlHeader();