public override void EndInit()
        {
            base.EndInit();
            ExtTextBlock block = new ExtTextBlock {
                Width = 100, Height = 20, Text = "Test Block"
            };
            ExtButton button = new ExtButton {
                Width = 100, Height = 20, Content = "ClickMe"
            };
            ExtLabel label = new ExtLabel {
                Width = 100, Height = 30, Content = "Test Label"
            };
            ExtTextBox txtBox = new ExtTextBox {
                Width = 100, Height = 20, Text = "Hi There"
            };
            Grid g = (Grid)BaseControl.FindChild(this, "gridMain");

            g.Children.Add(button);
            g.Children.Add(block);
            g.Children.Add(label);
            g.Children.Add(txtBox);
            Grid.SetRow(block, 0);
            Grid.SetRow(button, 1);
            Grid.SetRow(label, 2);
            Grid.SetRow(txtBox, 3);
            button.Click += button_Click;
        }
 internal static void Register()   // .config -> gtyperegister_static_function=
 {
     ExtTextBox.Register();
     ExtComboBox.Register();