Easyui datagrid 行编辑时某一列失去焦点时触发事件（列类型为combobox）

 //datagrid初始化
$(\'#dg\').datagrid({
        nowrap: false,
        striped: true,
        border: false,
        collapsible: false, //是否可折叠的  
        fit: true, //自动大小
        fitColumns: false,
        //url: "",
        datatype: \'json\',
        remoteSort: false,
        idField: \'detail_id\',
        singleSelect: true, //是否单选  
        rownumbers: true, //行号   
        loadMsg: \'数据加载中请稍后……\',
        columns: [[
           { field: \'id\', hidden: \'hidden\' },
           { field: \'line_number\', hidden: \'hidden\', title: \'编号\', width: 40, align: \'center\' },
           {
               field: \'goods_class\', title: \'物品分类\', width: 200, align: \'center\',
               editor: { type: \'combobox\', options: { valueField: \'id\', textField: \'text\', url: \'\', required: true, editable: true } }, formatter: format_goods_class
           },
           { field: \'goods_short_name\', title: \'物品简称\', width: 100, align: \'center\', editor: { type: \'textbox\', options: { required: true, editable: true } } },
           { field: \'goods_full_name\', title: \'物品名称/规格描述\', width: 180, align: \'center\', editor: { type: \'textbox\', options: { required: true, editable: true } } },
           {
               field: \'product_line\', title: \'Product Line\', width: 100, align: \'center\',
               editor: { type: \'combobox\', options: { valueField: \'dictionary_name\', textField: \'dictionary_name\', url: \'\', required: true, editable: false } }
           },
           { field: \'qty\', title: \'请购数量\', width: 80, align: \'center\', editor: { type: \'numberbox\', options: { min: 0.01, precision: 2, required: true, editable: true } } },
           {
               field: \'unit\', title: \'单位\', width: 80, align: \'center\',
               editor: {
                   type: \'combobox\', options: {
                       valueField: \'id\', textField: \'text\',
　　　　　　　　　　　　　 //列数据列表
                       data: unit_list,
                       required: true, editable: true
                   }
               }
           }]],
        onBeginEdit: function (index, row) {
            //获取单位的编辑器
            var unitditor = $(\'#dg_detail\').datagrid(\'getEditor\', { index: index, field: \'unit\' });

            //下拉列表失去焦点事件
            $("input", unitditor.target.next("span")).blur(function () {
                var flag = false;

                //判断该课程是否存在于下拉列表中datas获取的下拉列表中的数据
                for (var i = 0 ; i < unit_list.length; i++) {
                    if (unitditor.target.combobox(\'getValue\') == unit_list[i].id && unitditor.target.combobox(\'getValue\') != "") {
                        flag = true;
                    }
                }

                if (flag == false) {
                    //赋值为空
                    unitditor.target.combobox(\'setValue\', \'\');
                }
            });
        }
    });