EasyUI datagrid动态添加列

任务描述：根据用户选择时间段，生成列数据，如图

一、先定义好datagrid固定的数据列

    <script type="text/javascript">
        $(document).ready(function () {
            $("#td_Radio").datagrid({
                striped: true,
                border: true,
                iconCls: ‘icon-edit‘, //图标
                singleSelect: true,
                autoRowHeight: true,
                rownumbers: true,
                fitColumns: false,
                fit: false,
                idField: ‘cmem_id‘,
                pagination: true, //是否分页
                columns: [[
                         { field: ‘cregion_id‘, title: ‘调查地区‘, width: 100 },
                         { field: ‘cfm_ename‘, title: ‘节目名称‘, width: 100 },
                         { field: ‘cfamilyid‘, title: ‘家庭编号‘, width: 100 },
                         { field: ‘CSTBINSTALLDATE‘, title: ‘安装时间‘, width: 100 },
                 ]]
            });
            //设置分页控件
            var p = $(‘#td_Radio‘).datagrid(‘getPager‘);
            $(p).pagination({
                pageSize: 10, //每页显示的记录条数，默认为10
                pageList: [10, 20, 30], //可以设置每页记录条数的列表
                beforePageText: ‘第‘, //页数文本框前显示的汉字
                afterPageText: ‘页    共 {pages} 页‘,
                displayMsg: ‘当前显示 {from} - {to} 条记录   共 {total} 条记录‘
            });
        })
    </script>

二、用户点击查询的时候根据选择时间生成列数据，列是通过拼接字符串生成的

  var options = {};
           //返回日期类型2016-07-01
            function DataTime(date) {
                var mon = date.getMonth() + 1;         //getMonth()返回的是0-11，则需要加1
                if (mon <= 9) {                                     //如果小于9的话，则需要加上0
                    mon = "0" + mon;
                }
                var day = date.getDate();                   //getdate()返回的是1-31，则不需要加1
                if (day <= 9) {                                     //如果小于9的话，则需要加上0
                    day = "0" + day;
                }
                return date.getFullYear() + "-" + mon + "-" + day;
            }            //当数据值为0时，设置改变背景色
            function cellStyler(value, row, index) {
                if (value == 0) {
                    return ‘background-color:#EE9572;‘;
                }
            }
    //绑定查询按钮的click事件
   $("#btnSearch").bind(‘click‘, function () {
          var dg = $("#td_Radio");
          var url = "AjaxHandler/RadioFamilyDayNumber.ashx?Action=LoadGrid&NetWork=" + NetWork + "&FmID=" + FmID + "&StarTime=" + StarTime + "&EndTime=" + EndTime + "&FmName=" + FmName + "&NetWorkName=" + NetWorkName;
          loadDg(dg, url);
          })
       //加载DataGrid数据
       function loadDg(dg, url) {
            dg.datagrid({
            url: url
            });
        fetchData();//调用生成列方法
        }
            //动态添加列
            function fetchData() {
                var StarTime = $("#starTime").datebox("getValue");//得到开始时间
                var EndTime = $("#endTime").datebox("getValue");//得到结束时间
                var FmID = $("#cmbFmName").combobox("getValue");//获取FMID
                var StarDate = new Date(StarTime.substr(6, 4), StarTime.substr(0, 2) - 1, StarTime.substr(3, 2));//通过截取字符串，得到需要的DateTime类型
                var EndDate = new Date(EndTime.substr(6, 4), EndTime.substr(0, 2) - 1, EndTime.substr(3, 2));
                var days = EndDate.getTime() - StarDate.getTime();//获取相差天数
                var time = parseInt(days / (1000 * 60 * 60 * 24));//转换相差天数为int类型数据
                var nextDate = StarDate;
                var s = "";
                s = "[[";
                if (FmID == "-1")
                    s = s + " { field: ‘CREGION_ID‘, title: ‘调查地区‘, width: 100 },{ field: ‘CFAMILYID‘, title: ‘家庭编号‘, width: 100 },{ field: ‘CSTBINSTALLDATE‘, title: ‘安装时间‘, width: 100 },";
                else
                    s = s + " { field: ‘CREGION_ID‘, title: ‘调查地区‘, width: 100 },{ field: ‘CFM_ENAME‘, title: ‘节目名称‘, width: 100 },{ field: ‘CFAMILYID‘, title: ‘家庭编号‘, width: 100 },{ field: ‘CSTBINSTALLDATE‘, title: ‘安装时间‘, width: 100 },";
                for (var i = 0; i <= time; i++) {
                    if (i == 0) {
                        s = s + "{field:‘" + DataTime(nextDate) + "‘,title:‘" + DataTime(nextDate) + "‘,width:80,styler:cellStyler},";
                    }
                    else {
                        nextDate = new Date(nextDate.getTime() + 24 * 60 * 60 * 1000);  //后一天
                        s = s + "{field:‘" + DataTime(nextDate) + " ‘,title:‘" + DataTime(nextDate) + "‘,width:80,styler:cellStyler},";
                    }
                }
                s = s + "]]";
                options = {};
                options.columns = eval(s);
                $(‘#td_Radio‘).datagrid(options);
            }