TreeView控件的展开与折叠

在窗体中添加一个TreeView控件,设置CheckBox属性为True，绑定数据

Archive jkj = new Archive();//自定义类
        public void Bind()
        {
            DataTable rol = jkj.GetDataTable("select rolesid,description from roles","roles");
            
            this.listBox1.DataSource = rol;
            this.listBox1.DisplayMember = "description";
            this.listBox1.ValueMember = "rolesid";
            this.treeView1.Nodes.Clear();
            DataTable mod = jkj.GetDataTable("select modelno,modelename from modelname", "modelname");
            foreach (DataRow mrow in mod.Rows)
            {
                TreeNode mtn = new TreeNode();
                mtn.Text = mrow["modelename"].ToString();
                mtn.Tag = mrow["modelno"].ToString();
                this.treeView1.Nodes.Add(mtn);
                string sql = "select funcno,cname from funcname where modelno=" + int.Parse(mtn.Tag.ToString())+" order by funcno";
                DataTable fun = jkj.GetDataTable(sql, "funcname");
                foreach (DataRow frow in fun.Rows)
                {
                    TreeNode ftn = new TreeNode();
                    ftn.Text = frow["cname"].ToString();
                    ftn.Tag = frow["funcno"].ToString();
                    mtn.Nodes.Add(ftn);
                }
            }
            this.treeView1.ExpandAll();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Bind();//绑定数据源
        }

// 在TreeView控件的AfterCheck事件中加入：

private void treeView1_AfterCheck(object sender, TreeViewEventArgs e)
        {
            TreeView tree = (TreeView)sender;
            tree.AfterCheck -= new TreeViewEventHandler(this.treeView1_AfterCheck);

            //折叠其他同级节点   
            TreeNode parentNode = e.Node.Parent;
            if (parentNode != null)
            {
                foreach (TreeNode tn in parentNode.Nodes)
                {
                    if (tn != e.Node)
                        tn.Collapse();
                }
            }
            else
            {
                foreach (TreeNode tn in tree.Nodes)
                {
                    if (tn != e.Node)
                        tn.Collapse();
                }
            }

            //标记该节点的所有子节点的选中状态与该节点一致   
            foreach (TreeNode tn in e.Node.Nodes)
                tn.Checked = e.Node.Checked;

            //if   (e.Node.Checked)   
            e.Node.ExpandAll(); //如果该节点为选中，展开该节点   
            //else   
            // e.Node.Toggle(); //如果该节点没有选中：如果该节点处于折叠状态，则展开该节点，否则折叠它  

            //如果当前节点的父节点下的所有子节点都没有选中，去掉父节点的选中   
            if (e.Node.Checked == false && e.Node.Parent != null)
            {
                bool found = false; //父节点的子节点中至少有一个节点被选中，则found   =   true   
                foreach (TreeNode tn in e.Node.Parent.Nodes)
                {
                    if (tn.Checked == true)
                    {
                        found = true;
                        break;
                    }
                }
                if (found == false) //没有找到任何被选中的子节点   
                {
                    e.Node.Parent.Checked = false;
                    e.Node.Parent.Collapse();
                }
            }

            tree.AfterCheck += new TreeViewEventHandler(this.treeView1_AfterCheck);
            this.treeView1.FullRowSelect = true;

////下面的代码作用是：选取父节点后，选取其所有子节点。
            //foreach (TreeNode tn in e.Node.Nodes)
            //{
            //    tn.Checked = e.Node.Checked;

            //}
        }