$(document).ready(function() {
        var array = new Array();
        $("#sl").children().each(function() {
            $(this).children().each(function() {
                //判断checkbox选中 得到数据 可以push到数组array
            });
        });
    });
//#sl为资源模块 等一级模块的父级ID

------解决方案--------------------
供参考！我上星期写的一个树形结构数据绑定DropDownList
C# code
 private void BindDrpClass() {
            IList<Cargos.CargoCategory> car = Global.CargoCategoryManager.Get();
            DataTable dt = new DataTable();
            dt.Columns.Add("Id", typeof(int));
            dt.Columns.Add("Name", typeof(string));
            dt.Columns.Add("Parent", typeof(int));
            dt.Columns.Add("Description", typeof(string));
            foreach (Cargos.CargoCategory c in car) {
                dt.Rows.Add(new object[] { c.Id, c.Name,
                    c.Parent==null?0:c.Parent.Id, c.Description });
            }
            DropDownList1.Items.Clear();
            //DropDownList1.Items.Add(new ListItem("作为根", "0"));
            //DataRow[] drs = dt.Select("Parent= "+dt.Rows[0][2]);
            for (int i = 0; i < dt.Rows.Count; i++) {
                if (Convert.ToInt32(dt.Rows[i][2]) == 0) {
                    string classid = dt.Rows[i][0].ToString();
                    string classname = dt.Rows[i][1].ToString();
                    //顶级分类显示形式
                    classname = "├" + classname;
                    DropDownList1.Items.Add(new ListItem(classname, classid));
                    int sonparentid = int.Parse(classid);
                    string blank = "    ├──";
                    //递归子分类方法
                    BindDrpNode(sonparentid, dt, blank);
                }
                DropDownList1.DataBind();
            }
        }
        private void BindDrpNode(int parentid, DataTable dt, string blank) {
            for (int i = 0; i < dt.Rows.Count; i++) {
                if (Convert.ToInt32(dt.Rows[i][2]) == parentid) {
                    string classid = dt.Rows[i][0].ToString();
                    string classname = dt.Rows[i][1].ToString();
                    classname = blank + classname;
                    DropDownList1.Items.Add(new ListItem(classname, classid));
                    int sonparentid = int.Parse(classid);
                    string blank2 = "        " + blank + "──";
                    BindDrpNode(sonparentid, dt, blank2);
                }
            }
        }

------解决方案--------------------

三层循环：
StringBuilder test = new StringBuilder();
foreach (TreeNode node in TreeView1.Nodes)
{
 if(!node.Selected) continue;
 test.Append(node.Text);
 foreach (TreeNode SecondNode in node.ChildNodes) 
 {
    if(!SecondNode.Selected) continue;
    test.Append(SecondNode.Text);
    foreach (TreeNode ThridNode in node.ChildNodes) 
    {
       if(!ThridNode.Selected) continue;
       test.Append(ThridNode.Text);
    }
 }
 //这里操作你的数据保存方法。
 //test.ToString();就是你要的数据。
}
递归：
private string reText(TreeNodeCollection nodes)
{
  StringBuilder test = new StringBuilder();
  foreach (TreeNode node in nodes)
 {
    if(!node.Selected) conti