C#

public interface IViewModel
{
    string VName { get; }

    Action<Control> VMouseDown { get; set; }
}

public interface IControl : IViewModel
{
    new Action<Control, Point> VMouseDown { get; set; }
}

public class ViewModel : IViewModel
{
    public string VName { get; }

    public Action<Control> VMouseDown { get; set; }
}

public class MyStupidControl : ViewModel, IControl
{
    public new Action<Control, Point> VMouseDown { get; set; }
} //       ^^^

BillWoodruff wrote:

I suppose there's an outside chance that what I may be observing here has something to do with the "nature" of the 'Action and 'Func delegates

BillWoodruff wrote:

But, then, what is the use of over-riding hiding in an Interface for ? Why allow it ?

Quote: Implementing Interface Members Explicitly[^]

Consider implementing interface members explicitly to simulate variance (that is, change parameters or return type in overridden members).

This is often done to offer strongly-typed versions of the interface members.

private void Form1_Resize(object sender, EventArgs e)
{
    if (this.WindowState == FormWindowState.Maximized)
    {
        this.WindowState = FormWindowState.Normal;
        this.Size = MaximumSize;

        Rectangle scrn = Screen.PrimaryScreen.WorkingArea;

        this.Left = scrn.Width / 2 - this.Width / 2;
        this.Top = scrn.Height / 2 - this.Height / 2;

        this.Refresh();
    }
}

Process[] processes = Process.GetProcesses();
foreach (Process p in processes)
    {
    if (!String.IsNullOrEmpty(p.MainWindowTitle))
        {
        Console.WriteLine("Process:         {0}\n   ID:           {1}\n   Window title: {2}", p.ProcessName, p.Id, p.MainWindowTitle);
        }
    }

if (p.MainWindowTitle == "Untitled - Paint")
    {
    p.Kill();
    }