Jquery easyUI datagrid 服务器端动态生成列配置返回到前台显示

近几天老大让修改以前的项目，客户反应用一端时间IE假死。以前的项目是用extjs写的，跟同事商量后，改用easyUI改造界面，前面规则的表格展示还挺顺利。今天遇到一个页面，前端显示的表格是动态生成，本菜鸟忙了大半天终于搞定。

前台JS代码：

//查询方法function query() {    var params = getParam();    if (params.strStnm == undefined || params.strStnm == '' || params.strStnm == '请选择站点') {        $.messager.alert("提示", "请先选择站点", "warning", null);        return;    }    var url = "MultidropRain.aspx";    $.post(url, params,showGrid, "json");}//处理返回结果，并显示数据表格function showGrid(data) {    if (data.data[0].rows.length == 0) {        $.messager.alert("结果", "没有数据!", "info", null);    }    var options = {        width: "auto",        height: "auto",        rownumbers: true    };    options.columns = eval(data.columns);//把返回的数组字符串转为对象，并赋于datagrid的column属性    var dataGrid = $("#rainGrid");    dataGrid.datagrid(options);//根据配置选项，生成datagrid    dataGrid.datagrid("loadData", data.data[0].rows); //载入本地json格式的数据}

后台生成columns的方法：

 /// <summary>    /// 从dataTable创建 jquery easyui datagrid格式的columns参数    /// </summary>    /// <param name="dt"></param>    /// <returns></returns>    protected string CreateDataGridColumnModel(DataTable dt)    {        StringBuilder columns = new StringBuilder("[[");        int width = 0;        foreach (DataColumn col in dt.Columns)        {            //控制列的宽度 第一列日期宽度为139,其余列为列名的汉字长度*20px            if (col.ColumnName=="日期")            {                width = 139;            }            else            {                width = col.ColumnName.Length * 20;            }            columns.AppendFormat("{{field:'{0}',title:'{1}',align:'center',width:{2}}},",col.ColumnName,col.ColumnName,width);        }        if (dt.Columns.Count>0)        {            columns.Remove(columns.Length - 1, 1);//去除多余的','号        }        columns.Append("]]");        return columns.ToString();    }

后台返回的JSON字符串：

{"columns":"[[{field:'日期',title:'日期',align:'center',width:139},{field:'乔河',title:'乔河',align:'center',width:40},{field:'城壕',title:'城壕',align:'center',width:40},{field:'墩山',title:'墩山',align:'center',width:40}]]","data":[{"page":"0","total":"12","rows":[{"日期":"2011-12-12 20时","乔河":"56.00","城壕":"","墩山":""},{"日期":"2012-02-07 15时","乔河":"54.00","城壕":"","墩山":""},{"日期":"2012-02-08 09时","乔河":"51.00","城壕":"","墩山":""},{"日期":"2012-02-09 10时","乔河":"","城壕":"53.00","墩山":""},{"日期":"2012-02-09 15时","乔河":"","城壕":"","墩山":"54.00"},{"日期":"2012-02-09 15时","乔河":"","城壕":"","墩山":""},{"日期":"2012-02-09 16时","乔河":"","城壕":"","墩山":""},{"日期":"2012-02-13 16时","乔河":"","城壕":"","墩山":""},{"日期":"2012-02-13 16时","乔河":"","城壕":"","墩山":""},{"日期":"2012-02-14 13时","乔河":"","城壕":"","墩山":""},{"日期":"2012-02-15 09时","乔河":"","城壕":"","墩山":""},{"日期":"2012-02-16 13时","乔河":"","城壕":"","墩山":""}]}]}

格式：{ "columns":"[[ {field:'field1','title':'title1'},{...} ]]",data:[{page:"pageIndex",total:"totalNum",rows:[{name1:value,name2:value},{...}]}]}
特别注意JSON格式：由于刚开始返回的json格式不对，回调函数怎么都不能调用。着实郁闷了很久。对于自己后台拼json的同学，请务必注意json格式问题。

data数组里面放的是 datagrid要求的标准json格式。