首先来看一下效果
页面加载之初
节点全部展开后
首先数据库的表结构如下
其中Id为主键,PId为关联到自身的外键
两个字段均为GUID形式
层级关系主要靠这两个字段维护
其次需要有一个类型
public class MenuType { public Guid Id { get; set; } public Guid PId { get; set; } public string MenuName { get; set; } public string Url { get; set; } public int OrderNum { get; set; } public int SonCount { get; set; } }
此类型比数据库表增加了一个属性
SonCount
这个属性用来记录当前节点的子节点的个数
注意：也可以把此属性放在数据库中，性能上会提升一些，但需要增加额外的代码来维护此字段
接下来看一下取数据的方式
protected void Page_Load(object sender, EventArgs e) { if (Request["Action"] == "AJAX") { var result = GetMenu(Request["pid"]); JavaScriptSerializer serializer = new JavaScriptSerializer(); string sRet = serializer.Serialize(result); Response.Write(sRet); Response.End(); } }
页面加载之初判断是否需要获取菜单数据
其中请求参数pid为客户端需要获取的节点ID
如果请求顶级节点，则此参数的值为00000000-0000-0000-0000-000000000000
GetMenu函数获取需要请求的节点数据
private List<MenuType> GetMenu(string pid) { var result = new List<MenuType>(); SqlConnection conn = new SqlConnection("Data Source=.;Initial Catalog=SHU;User ID=sa;Password=allen;"); conn.Open(); SqlCommand cmd = new SqlCommand(); cmd.Connection = conn; cmd.CommandText = "select a.*,b.cout as count from Menu a left join (select COUNT(*) as cout,Menu.PId from Menu group by Menu.PId) as b on a.Id = b.PId where a.PId = '" + pid + "' order by OrderNum"; SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection); while (dr.Read()) { var obj = new MenuType(); obj.Id =Guid.Parse(dr["Id"].ToString()); obj.MenuName = dr["MenuName"].ToString(); obj.OrderNum = Convert.ToInt32(dr["OrderNum"]); obj.PId = dr["PId"] == DBNull.Value ? Guid.Empty : Guid.Parse(dr["PId"].ToString()); obj.Url = dr["Url"].ToString(); obj.SonCount = dr["count"] == DBNull.Value ? 0 : Convert.ToInt32(dr["count"]); result.Add(obj); } return result; }
在本DEMO中使用JavaScriptSerializer来序列化菜单数组
前台的代码如下
<asp:Content runat="server" ContentPlaceHolderID="HeadContent"> <link href="https://www.jb51.net/Scripts/themes/default/style.css" type="text/css" /> <script src="https://www.jb51.net/Scripts/jquery.js" type="text/javascript"></script> <script src="https://www.jb51.net/Scripts/jquery.jstree.js" type="text/javascript"></script> <script> $(function () { $.getJSON("/default.aspx?ACTION=AJAX&pid=00000000-0000-0000-0000-000000000000", function (result) { $.each(result, function (i, item) { var typeN = item.SonCount > 0 ? "jstree-closed" : "jstree-leaf"; $("#tree").append("<li><a href='#'>" + item.MenuName + "</a></li>"); }); $("#demo2").jstree({ "plugins": ["themes", "html_data", 'types', "ui", "checkbox"], 'core': { 'animation': 0 }, "types": { "types": { "person": { "icon": { "image": "/Scripts/themes/default/person.png"} }, "depar2": { "icon": { "image": "/Scripts/themes/default/depar2.png"} }, "default": { "icon": { "image": "/Scripts/themes/default/depar1.png"} } } } }).bind("open_node.jstree", function (e, data) { var id = data.rslt.obj[0].id; if ($("#" + id + " li").length > 0) { return; } $.getJSON("/default.aspx?ACTION=AJAX&pid=" + id.replace("phtml_", ""), function (result) { var str = "<ul>" $.each(result, function (i, item) { var typeN = item.SonCount > 0 ? "jstree-closed" : "jstree-leaf"; var icon = item.SonCount > 0 ? "depar2" : "person"; str += "<li rel = '" + icon + "'><a href='#'> " + item.MenuName + "</a></li>"; }); str += "</ul>"; $("#" + id).append(str); var tree = jQuery.jstree._reference("#" + id); tree.refresh(); $("ins[class='jstree-checkbox jstree-icon']").removeClass("jstree-icon"); $(".jstree-checkbox").attr("style", ""); }); }); }); }); </script> </asp:Content> <asp:Content runat="server" ContentPlaceHolderID="MainContent"> <div> <ul> </ul> </div> </asp:Content>
页面加载之初，先请求顶级节点
如果顶级节点的SonCount属性大于0
则使节点为闭合状态（样式为jstree-closed）
如果节点无子节点
则该节点的样式为jstree-leaf
当用户点击闭合状态的节点时，客户端发起请求
并把点击节点的ID传给后端，后端获取到点击节点的子节点后
通过append添加到点击节点下
至此，无限分级的树创建完成
其中不包含数据库