MouseLeftButtonDown
is not a property but an event. You register a callback to the event using the +=
operator:
var e = new Ellipse {
Name = "FirstEllipse",
Width = 150,
Height = 100,
Margin = new Thickness(200, 150, 0, 0),
Fill = Brushes.Red };
e.MouseLeftButtonDown += Ellipse_MouseLeftButtonDown;
canvas.Children.Add(e);