System.Windows.Forms.ComboBox.OnMouseDownCB C# (CSharp) Method

		void OnMouseDownCB (object sender, MouseEventArgs e)
		{
			Rectangle area;
			if (DropDownStyle == ComboBoxStyle.DropDownList)
				area = ClientRectangle;
			else
				area = button_area;

			if (area.Contains (e.X, e.Y)) {
				if (Items.Count > 0)
					DropDownListBox ();
				else {
					button_state = ButtonState.Pushed;
					OnDropDown (EventArgs.Empty);
				}
				
				Invalidate (button_area);
				Update ();
			}
			Capture = true;
		}