TreeView的联动复选框

方法引用于：http://www.cnblogs.com/javaca88/archive/2006/10/26/540827.html

private void tvSysFunctionMenu_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
        {
            if (e.Node != tvSysFunctionMenu.Nodes[0])
            {
                SetChildNodeChecked(e.Node);
                SetParentNodeChecked(e.Node);
            }
            else
            {
                SetChildNodeChecked(e.Node);
            }
        }


        //根据父节点状态设置子节点的状态
        private void SetChildNodeChecked(TreeNode parentNode)
        {
            foreach (TreeNode node in parentNode.Nodes)
            {
                node.Checked = parentNode.Checked;
                if (node.Nodes.Count > 0)
                {
                    SetChildNodeChecked(node);
                }
            }
        }

        //根据子节点状态设置父节点的状态
        private void SetParentNodeChecked(TreeNode childNode)
        {
            TreeNode parentNode = childNode.Parent;
            if (!parentNode.Checked && childNode.Checked) //当子结点选中，父结点没选中时，则：选中父结点
            {
                parentNode.Checked = true;
            }
            else if (parentNode.Checked && !childNode.Checked) //取消选中其下全部子结点时，其父结点也取消
            {
                int checks = 0; //统计子结点的个数（为0时表示取消了其下全部子结点）
                foreach (TreeNode node in parentNode.Nodes)
                {
                    if (node.Checked)
                    {
                        checks++;
                        break;
                    }
                }
                if (checks == 0) //子结点都取消选中时，其父结点也取消
                {
                    parentNode.Checked = false;
                    if (!parentNode.Index.Equals(0))
                    {
                        SetParentNodeChecked(parentNode);
                    }
                }
            }
        }

        //节点选中状态更改
        protected void TreeNodeCheckStatusChanged(object sender, TreeNodeMouseClickEventArgs e)
        {
            SetChildNodeChecked(e.Node);
            // 判断是否是根节点
            if (!e.Node.Index.Equals(0))
            {
                SetParentNodeChecked(e.Node);
            }
        }

        private bool updateTreeNode = false;
        void treeView1_AfterCheck(object sender, TreeViewEventArgs e)
        {
            if (updateTreeNode) return; // 如果在刷新中
            updateTreeNode = true;
            try
            {
                SetChildTreeNodeChecked(e.Node, e.Node.Checked); // 同步子节点
                SetParentTreeNodeChecked(e.Node, e.Node.Checked);
            }
            finally
            {
                updateTreeNode = false;
            }
        }

        private void SetChildTreeNodeChecked(TreeNode currentTreeNode, bool isChecked) // 同步子节点
        {
            if (currentTreeNode == null) return;
            currentTreeNode.Checked = isChecked;
            foreach (TreeNode treeNode in currentTreeNode.Nodes)
                SetChildTreeNodeChecked(treeNode, isChecked);
        }

        private void SetParentTreeNodeChecked(TreeNode currentTreeNode, bool isChecked)
        {
            if (currentTreeNode == null) return;
            currentTreeNode.Checked = isChecked;
            if (isChecked) // 如果选中本节点,则选中全部上级节点
            {
                SetParentTreeNodeChecked(currentTreeNode.Parent, isChecked);
            }
            else
            {
                if (currentTreeNode.Parent != null && currentTreeNode.Parent.Checked)
                {
                    foreach (TreeNode treeNode in currentTreeNode.Parent.Nodes)
                        if (treeNode.Checked) return;
                    SetParentTreeNodeChecked(currentTreeNode.Parent, isChecked); // 判断是否所有的兄弟节点Checked都为false
                }
            }
        }