$(document).ready(function(){
	var treeGrid;
	//初始化TreeGrid数据
	getTreeGridDate();
});
function getTreeGridDate(idMerchant){
	if(!idMerchant){
		idMerchant=-1;
	}
	$.ajax(
		type:"get",url:basePath + “xxx/xxx/xx.do?adt=”+new Date().getTime(),data:{"idMerchant":idMerchant},dataType:"json",success:function(data){//后端返回json格式的字符串
			if(data){
				$("div1").empty();//清空原来的TreeGrid
				var  dataTreeGridSource = eval(data);//转成数组对象
			var config = {
		            id: "tg1",width: "800",renderTo: "div1",headerAlign: "left",headerHeight: "30",dataAlign: "left",indentation: "20",folderOpenIcon: "images/folderOpen.gif",folderCloseIcon: "images/folderClose.gif",defaultLeafIcon: "images/defaultLeaf.gif",hoverRowBackground: "false",folderColumnIndex: "1",itemClick: "itemClickEvent",columns: [
		            			{ headerText: "",headerAlign: "center",dataAlign: "center",width: "20",handler: "customCheckBox" },{ headerText: "名称",dataField: "name",handler: "customOrgName" },{ headerText: "拼音码",dataField: "code",width: "100" },{ headerText: "负责人",dataField: "assignee",width: "100" }
					],data:dataTreeGridSource 
		        	};
		        
		       //创建一个组件对象
	        	treeGrid = new TreeGrid(config);
	       		 treeGrid.show(); 
			}else if(!data){
				$("div1").empty();
				$("div1").append("<table id=\"tg1\" ................暂无数据....");
			}
		},error:function(){
			alert("查询异常，请稍后再试或联系管理员。。。");
		}

	});
}

var idArray = ...;//从后台查询得到

function customCheckBox(row,col) {

for(var i in idArray){

if(idArray[i] == row.idOper){

return "<input type='checkBox' name='idCategory' value="+row.idOper+" check='checked'>";

}

}
return "<input type='checkBox' name='idCategory' value="+row.idOper+">";
}

此外empty（）函数在做清除原来数据方面有很大作用。如级联下拉的清除也需要如此。