一个很简单的jquery+xml+ajax的无刷新树结构(无css，后台是c#)

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Data.Linq; 
using System.Xml; 
using System.Xml.Linq; 
namespace WebApplication3 { 
public partial class WebForm1: System.Web.UI.Page { 
protected void Page_Load(object sender, EventArgs e) { 
int id = Convert.ToInt32(Request["parentID"]); 
GetXML(id); 
} 
public IList < Product > GetList() { 
return new List < Product > () { 
new Product() { 
Id = 1, 
ParentId = 0, 
HasChild = 1, 
Name = "aaaaa" 
}, 
new Product() { 
Id = 2, 
ParentId = 1, 
HasChild = 1, 
Name = "bbbb1" 
}, 
new Product() { 
Id = 3, 
ParentId = 2, 
HasChild = 0, 
Name = "ccccc2" 
}, 
new Product() { 
Id = 4, 
ParentId = 2, 
HasChild = 0, 
Name = "ddddd3" 
}, 
new Product() { 
Id = 5, 
ParentId = 1, 
HasChild = 0, 
Name = "eeeeee4" 
}, 
new Product() { 
Id = 6, 
ParentId = 3, 
HasChild = 0, 
Name = "ffffff5" 
}, 
new Product() { 
Id = 7, 
ParentId = 4, 
HasChild = 0, 
Name = "ggggggg6" 
}, 
new Product() { 
Id = 8, 
ParentId = 7, 
HasChild = 0, 
Name = "hhhhhhh7" 
}, 
new Product() { 
Id = 9, 
ParentId = 0, 
HasChild = 0, 
Name = "jjjjjjj8" 
}, 
new Product() { 
Id = 10, 
ParentId = 0, 
HasChild = 0, 
Name = "yyyyyyyy9" 
} 
}; 
} /// <summary> 
/// 通过父节点读取子节点并且拼接成xml给前台 
/// </summary> 
/// <param name="parentId"></param> 
public void GetXML(int parentId) { 
List<Product> list = GetList().Where(x => x.ParentId == parentId).ToList(); 
XElement xElement = new XElement("textTree"); 
foreach (Product p in list) { 
xElement.Add(new XElement("value", new XAttribute("id", p.Id),p.Name)); 
} 
xElement.Save("d:\\kissnana.xml"); 
XmlDocument xdocument = new XmlDocument(); 
xdocument.Load("d:\\kissnana.xml"); 
Response.ContentType = "text/xml"; 
xdocument.Save(Response.OutputStream); 
Response.End(); 
} 
} 
public class Product { 
public int Id{set;get;} 
public int ParentId{set;get;} 
public int HasChild{set;get;} 
public string Name{set;get;} 
}} 
思路很简单，后台利用xml送往前台通过jquery接收处理拼接ul, 
li原理（利用 < li > 中嵌套 < ul > 的方式，局部读取一节点下的所有直属子节点，每次点击读取，读取过的话，则进入GetDisplayOrNot（）方法判断显示和隐藏节点）html代码： < body > <form id = "form1" 
runat = "server" > <input type = "button" 
value = "text" 
onclick = "LoadXml(0)" / ><div id = "root" > </div> 
</form > 
</body>

前台代码：

<script type="text/javascript"> 
var object1 = null; 
function LoadXml(id) { 
$.ajax({ 
type: " 
post ", 
url:" 
WebForm1.aspx ? parentID = "+id, 
dataType:" 
xml ", 
success: createTree 
}); 
} 
// 思路是每个父节点产生一个ul孩子并且ajax读取该父亲的直接儿子，拼接树 
function createTree(xml) { 
var obj = object1 == null ? ("#root ") : (object1);//判断是不是第一次加载，如果第一次加载则是最外的div的id,否则是父节点 
$(obj).append(" < UL class = 'ULfather' > ");//添加ul对象 
$(xml).find(" 
value ").each(function() {//从xml里读出所有value节点信息，得到当前层次节点 
//拼接<li>和<a>,属性通过xml中的value节点的属性id和节点文本进行拼接 
$(obj).children(".ULfather ").append(" < li > <a id = " + $(this).attr(" 
id ") + " > " + $(this).text() + " < /a></li > "); 
var alink = "#" + $(this).attr(" 
id "); //得到当前超链接对象 
$(alink).bind(" 
click ", function() { //超连接绑定点击事件 
if ($(alink + " + ul ").size() <= 0) {//如果数据已经绑定则无需再次绑定，（如果超链接下个元素是ul的话，说明数据已经绑过） 
object1 = $(alink).parent(" 
li "); 
LoadXml($(this).attr(" 
id ")) 
} 
else { 
GetDisplayOrNot($(alink)); 
} 
}); 
}); 
} 
//节点显示或影藏 
function GetDisplayOrNot(obj) { 
if ($(obj).parent(" 
li ").children(" 
ul ").is(": hidden ")) { 
$(obj).parent(" 
li ").children(" 
ul ").css(" 
display ", " 
block "); 
} 
else { 
$(obj).parent(" 
li ").children(" 
ul ").css(" 
display ", " 
none "); 
} 
} 
</script>

后台：

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Data.Linq; 
using System.Xml; 
using System.Xml.Linq; 
namespace WebApplication3 
{ 
public partial class WebForm1 : System.Web.UI.Page 
{ 
protected void Page_Load(object sender, EventArgs e) 
{ 
int id =Convert.ToInt32(Request["parentID"]); 
GetXML(id); 
} 
public IList<Product> GetList() 
{ 
return new List<Product>() 
{ 
new Product(){ Id=1, ParentId=0, HasChild=1, Name="aaaaa" }, 
new Product(){ Id=2, ParentId=1, HasChild=1, Name="bbbb1" }, 
new Product(){ Id=3, ParentId=2, HasChild=0, Name="ccccc2" }, 
new Product(){ Id=4, ParentId=2, HasChild=0, Name="ddddd3" }, 
new Product(){ Id=5, ParentId=1, HasChild=0, Name="eeeeee4" }, 
new Product(){ Id=6, ParentId=3, HasChild=0, Name="ffffff5" }, 
new Product(){ Id=7, ParentId=4, HasChild=0, Name="ggggggg6" }, 
new Product(){ Id=8, ParentId=7, HasChild=0, Name="hhhhhhh7" }, 
new Product(){ Id=9, ParentId=0, HasChild=0, Name="jjjjjjj8" }, 
new Product(){ Id=10,ParentId=0, HasChild=0, Name="yyyyyyyy9" } 
}; 
} /// <summary> 
/// 通过父节点读取子节点并且拼接成xml给前台 
/// </summary> 
/// <param name="parentId"></param> 
public void GetXML(int parentId) 
{ 
List<Product> list = GetList().Where(x => x.ParentId == parentId).ToList(); 
XElement xElement = new XElement("textTree"); 
foreach (Product p in list) 
{ 
xElement.Add(new XElement("value", new XAttribute("id", p.Id),p.Name)); 
} 
xElement.Save("d:\\kissnana.xml"); 
XmlDocument xdocument = new XmlDocument(); 
xdocument.Load("d:\\kissnana.xml"); 
Response.ContentType = "text/xml"; 
xdocument.Save(Response.OutputStream); 
Response.End(); 
} 
} 
public class Product 
{ 
public int Id{set;get;} 
public int ParentId{set;get;} 
public int HasChild{set;get;} 
public string Name{set;get;} 
} 
}