将所选值传递给jQuery的select2 ajax调用

我正在尝试将多个参数（所选值）传递给multiple select2的ajax调用：

  $("#ddlMultiCourse").select2({ placeholder: "Search for Course", minimumInputLength: 1, allowClear: true, ajax: { // instead of writing the function to execute the request we use Select2's convenient helper url: url,//GetCourseList type: "POST", dataType: 'json', delay: 250, data: function (params) { return { term: params.term, // search term value: $("#ddlMultiCourse").val()//extra parameter }; }, processResults: function (data, params) { return { results: data }; } } }); 

我实际上想要将另一个参数传递给ajax调用…以前选择的值..

  public JsonResult GetCourseList(string term, string[] value) { try { var _courseList = _db.MultiCourses .Where(x => x.CourseCode.StartsWith(term)) .Select(x => new { id=x.Id, text=x.CourseCode }).ToList(); return Json(_courseList, JsonRequestBehavior.AllowGet); } catch (Exception ex) { return Json("", JsonRequestBehavior.AllowGet); } } 

现在我的价值为null。