(function ($) {
 //使用js的严格模式
 'use strict';

 $.fn.jqtree = function (options) {
  //合并默认参数和用户传过来的参数
  options = $.extend({}, $.fn.jqtree.defaults, options || {});

  var that = $(this);
  var strHtml = "";
  //如果用户传了data的值，则直接使用data，否则发送ajax请求去取data
  if (options.data) {
   strHtml = initTree(options.data);
   that.html(strHtml);
   initClickNode();
  }
  else {
   //在发送请求之前执行事件
   options.onBeforeLoad.call(that, options.param);
   if (!options.url)
    return;
   //发送远程请求获得data
   $.getJSON(options.url, options.param, function (data) {
    strHtml = initTree(data);
    that.html(strHtml);
    initClickNode();

    //请求完成之后执行事件
    options.onLoadSuccess.call(that, data);
   });
  }

  //注册节点的点击事件
  function initClickNode() {
   $('.tree li').addClass('parent_li').find(' > span').attr('title', '收起');
   $('.tree li.parent_li > span').on('click', function (e) {
    var children = $(this).parent('li.parent_li').find(' > ul > li');
    if (children.is(":visible")) {
     children.hide('fast');
     $(this).attr('title', '展开').find(' > i').addClass('icon-plus-sign').removeClass('icon-minus-sign');
    } else {
     children.show('fast');
     $(this).attr('title', '收起').find(' > i').addClass('icon-minus-sign').removeClass('icon-plus-sign');
    }

    $('.tree li[class="parent_li"]').find("span").css("background-color", "transparent");
    $(this).css("background-color", "#428bca");

    options.onClickNode.call($(this), $(this));
   });
  };

  //递归拼接html构造树形子节点
  function initTree(data) {
   var strHtml = "";
   for (var i = 0; i < data.length; i++) {
    var arrChild = data[i].nodes;
    var strHtmlUL = "";
    var strIconStyle = "icon-leaf";
    if (arrChild && arrChild.length > 0) {
     strHtmlUL = "<ul>";
     strHtmlUL += initTree(arrChild) + "</ul>";
     strIconStyle = "icon-minus-sign";
    }
    
    strHtml += "<li id=\"li_" + data[i].id + "\"><span id=\"span_" + data[i].id + "\"><i class=\"" + strIconStyle + "\"></i>" + data[i].text + "</span>" + strHtmlUL + "</li>";

   }
   return strHtml;
  };
 };

 //默认参数
 $.fn.jqtree.defaults = {
  url: null,
  param: null,
  data: null,
  onBeforeLoad: function (param) { },
  onLoadSuccess: function (data) { },
  onClickNode: function (selector) { }
 };

})(jQuery);

<div class="tree well">
 <ul id="ul_tree">
 </ul>
</div>

var testdata = [{
 id: '1',
 text: '系统设置',
 nodes: [{
  id: '11',
  text: '编码管理',
  nodes: [{
   id: '111',
   text: '自动管理',
   nodes: [{
    id: '1111',
    text: '手动管理',
    nodes: [{
     id: '11111',
     text: '底层管理',
    }]
   }]
  }]
 }]
}, {
 id: '2',
 text: '基础数据',
 nodes: [{
  id: '21',
  text: '基础特征'
 }, {
  id: '22',
  text: '特征管理'
 }]
}];

$(function () {
 $("#ul_tree").jqtree({
  data: testdata,
  param: { },
  onBeforeLoad: function (param) {
  },
  onLoadSuccess: function (data) { 
  },
  onClickNode: function (selector) {
  }
 });
});

 public class Tree
 {
  public string id { get; set; }
  public string text { get; set; }
  public object nodes { get; set; }
 }



　　　　 //返回tree的节点数据
  public JsonResult GetTreeData()
  {
   var lstRes = GetNode(1);
   return Json(lstRes, JsonRequestBehavior.AllowGet);
  }

  public List<Tree> GetNode(int iNum)
  {
   var lstRes = new List<Tree>();
   if (iNum > 5)
   {
    return lstRes;
   }
   for (var i = 1; i < 3; i++)
   {
    var oNode = new Tree { id = Guid.NewGuid().ToString(), text = iNum + "级节点" + i };
    var lstRes2 = GetNode(iNum + 1);
    oNode.nodes = lstRes2;
    lstRes.Add(oNode);
   }
   return lstRes;
  }

$(function () {
 $("#ul_tree").jqtree({
  url: "/Home/GetTreeData",
  param: { },
  onBeforeLoad: function (param) {
  },
  onLoadSuccess: function (data) {
  },
  onClickNode: function (selector) {
  }
 });
});