1.前端tree绑定时,使用onBeforeExpand事件:当节点展开时触发加载子节点,自动会向服务端发送请求:url为绑定url,参数为当前节点id this.tree = { method: 'GET', url: self.urls.queryCatalog, queryParams: ko.observable(), animate:true, lines: true, showLoading:true, loadFilter: function (d) { var list = ut