问当父节点被选中或被取消选中时，如何自动选中或取消选中所有下级节点？

EN

    private void HandleOnTreeViewAfterCheck(Object sender,
       TreeViewEventArgs e)
    {
        CheckTreeViewNode(e.Node, e.Node.Checked);
    }

    private void CheckTreeViewNode(TreeNode node, Boolean isChecked)
    {
        foreach (TreeNode item in node.Nodes)
        {
            item.Checked = isChecked;

            if (item.Nodes.Count > 0)
            {
                this.CheckTreeViewNode(item, isChecked);
            }
        }
    }

            //TreeView - myTreeview;
            myTreeview.BeginUpdate();
            //Loop through all the nodes of tree
            foreach (TreeNode node in myTreeview.Nodes)
            {
                //If node has child nodes
                if (HasChildNodes(node))
                {
                    if (node.Checked == true)
                    {
                        //Check all the child nodes.
                        foreach (TreeNode childNode in node.Nodes)
                        {
                            childNode.Checked = true;
                        }
                    }
                }
            }
            myTreeview.EndUpdate();

Hope this helps....