问jqGrid -如何禁用列可拖动但可以排序的列

EN

$(function () {   
    jQuery("#search_datagrid").jqGrid("GridUnload").jqGrid({
        url: '/Search/SearchDataGrid/',
        datatype: "json",
        contentType: "application/json; charset-utf-8",
        mtype: 'POST',
        postData: {
             search_word: search_word,
             baseLang: baseLang,
             targetLang: targetLang,
             products: products
        },
        rowNum: 20,
        rowList: [10, 20, 30, 50],
        colNames: columnNames,
        colModel: columnModels,
        shrinkToFit: true,
        height:'auto',
        autowidth: true,
        pager: "#search_pager",
        viewrecords: true,
        caption: "Result",
        subGrid: true,
        sortable: true,
        loadonce: true,
        gridview: true,

        subGridOptions: {
            "plusicon": "ui-icon-triangle-1-e",
            "minusicon": "ui-icon-triangle-1-s",
            "openicon": "ui-icon-arrowreturn-1-e"
        },
    })
    .jqGrid('navGrid', '#search_pager', { add: false, edit: false, del: false, search: false, refresh: false })
    .jqGrid('navButtonAdd', '#search_pager', {
        caption: "Select Columns",
        title: "Select Columns",
        buttonicon: "ui-icon-calculator",
        onClickButton: function () {
            jQuery("#search_datagrid").jqGrid('columnChooser');
        }
    })
    .jqGrid('setGroupHeaders', {
        useColSpanStyle: true,
        groupHeaders: [
          { startColumnName: '' + baseLang, numberOfColumns: 2, titleText: 'Language' },
        ]
    })
});
$(window).resize(function () {
    $("#search_datagrid").setGridWidth($(this).width() - $(this).width() / 10);
});