懒加载树[tree]、点击已经加载完成的树[tree]节点，再次加载该节点下一级的所有子节点
1.先来一个div，如下：[设置:id=treeboxbox_tree,如下]
<td valign="top">
<div id="treeboxbox_tree" style="width: 100%; height: 100%; float: left
border: 1px solid red;">
</div>
<br>
</td>
2.在页面加载后添加如下js代码：[每行代码意思都有解释]
tree = new dhtmlXTreeObject("treeboxbox_tree", "90%", "100%", 0);//treeboxbox_tree为上面的div的id；
tree.setSkin('dhx_skyblue'); //设这皮肤
tree.setImagePath("Dhx/samples/common/images/"); //设这图片的路径；
tree.enableDragAndDrop(1); //1表明可以drag； 0不可以drag；
tree.enableTreeLines(false);
tree.setOnClickHandler(onOneClick);//绑定onOneClick()方法；当单击树的节点是触发click事件；
tree.setXMLAutoLoading("ResponseXml.ashx");
tree.loadXML("ResponseXml.ashx?id=0");//请求的一般处理程序，下面将给出源码；?id=0,说明当页面加载的时候请求的是0级的节点集合；
3.后台一般处理程序如下:
View Code
1 /// <summary> 2 /// ResponseXml 的摘要说明 3 /// </summary> 4 public class ResponseXml : IHttpHandler 5 { 6 private string id = HttpContext.Current.Request["id"] ?? ""; 7 private bool root = true; 8 9 private Kyt.BLL.base_productclass2 baseProductclass2 = new base_productclass2(); 10 11 public void ProcessRequest(HttpContext context) 12 { 13 // context.Response.ContentType = "text/plain"; 14 context.Response.ContentType = "text/html"; 15 XmlDocument document = new XmlDocument(); 16 XmlElement rootEle = document.CreateElement("tree"); 17 XmlDeclaration declaration = document.CreateXmlDeclaration("1.0", "utf-8", ""); 18 document.InsertBefore(declaration, document.DocumentElement); 19 document.AppendChild(rootEle); 20 if (id == "0") 21 { 22 rootEle.SetAttribute("id", "0"); 23 } 24 else 25 { 26 rootEle.SetAttribute("id", id); 27 } 28 List<Kyt.Model.base_productclass2> list = listChildren(id); 29 foreach (var itemList in list) 30 { 31 XmlElement element = document.CreateElement("item"); 32 element.SetAttribute("text", itemList.mc); 33 rootEle.AppendChild(element); 34 element.SetAttribute("id", itemList.cpbm); 35 if (itemList.sy) 36 {//child 为0表明是树叶，为1表明不是树叶 37 element.SetAttribute("child", "0"); 38 } 39 else 40 { 41 element.SetAttribute("child", "1"); 42 } 43 } 44 XmlWriter w = new XmlTextWriter(context.Response.OutputStream, Encoding.UTF8); 45 document.WriteTo(w); 46 w.Flush(); 47 w.Close(); 48 49 // document.Save(context.Request.MapPath("test.xml")); 50 // context.Response.Write("<script>location='test.xml'</script>"); 51 52 } 53 54 /// <summary> 55 /// 列出写几编码，只列出直接的下级。如果参数为null，列出第一级别； 56 /// </summary> 57 /// <param name="cpbm"></param> 58 /// <returns></returns> 59 private List<Kyt.Model.base_productclass2> listChildren(string cpbm) 60 { 61 Kyt.BLL.base_productclass2 baseProductclass2 = new base_productclass2(); 62 if (cpbm != null) 63 { 64 Kyt.Model.base_productclass2 parent = baseProductclass2.GetModel(cpbm); 65 int level = parent.jc.Value + 1; 66 return baseProductclass2.GetModelList(" cpbm like '" + cpbm + "%' and jc=" + level.ToString()); 67 } 68 else 69 { 70 return baseProductclass2.GetModelList("jc=0"); 71 } 72 }
4.aspx页面要引用的文件，代码如下：
<link href="Jquery_ui/themes/base/jquery.ui.all.css" rel="stylesheet" type="text/css" /> <script src="../scripts/jquery-1.4.1-vsdoc.js" type="text/javascript"></script> <script src="Jquery_ui/themes/jquery-ui.js" type="text/javascript"></script> <link href="Dhx/codebase/dhtmlxtree.css" rel="stylesheet" type="text/css" /> <script src="Dhx/codebase/dhtmlxcommon.js" type="text/javascript"></script> <script src="Dhx/codebase/dhtmlxtree.js" type="text/javascript"></script>
dhx资源地址：http://dhtmlx.com/docs/products/dhtmlxTree/的找download，
至于juqery ui ，就很好找了，在这里就不多说了！
对于jquery ui 和dhx，找找demo，看看例子，有时候做项目有很大的用处！
5.要实现的树的结果图,如下：
当添加、删除、更新一个节点之后，要对该节点刷新-tree.refreshItem(id);//id为要刷新的节点id
