System.Windows.Forms.TreeNode.Toggle C# (CSharp) Method

        public void Toggle()
        {
            if (expanded == true) Collapse();
            else Expand();
        }

        protected override void OnMouseDown(MouseEventArgs e)
        {
            base.OnMouseDown(e);

            mouseDownAtNode = GetNodeAt(e.Location);
            if (mouseDownAtNode == null)
            {
                return;
            }

            // Try to toggle node with mouse.
            if (mouseDownAtNode.Nodes.Count > 0 &&
                e.X >= mouseDownAtNode.Bounds.X &&
                e.X <= mouseDownAtNode.Bounds.X + arrowSize)
            {
                mouseDownAtNode.Toggle();
                mouseDownAtNode = null; // Prevent node from being selected.
                return;
            }

            drag         = true;
            dragNode     = mouseDownAtNode;
            dragPosition = e.Location;
        }