(function ($) {
    $.fn.Schoolselected = function(settings, extraSettings) {
        var options;
        options = {
            NextSelId: '#Select2',
            //  SelTextId: '#Showmyselect',
            defaultv1: '',
            defaultv2: '',
            SchoolSelectData: ''
        };
        return this.each(function() {
            $.extend(options, settings, extraSettings);

            var _this, _thisnext;
            _this = $(this);
            _thisnext = $(options.NextSelId);

            $.each(options.SchoolSelectData, function(k, v) {

                appendOptionTo(_this, v.schoolName, v.Sval, options.defaultv1);
            });
            _this.change(function() {
                _thisnext.html("");

                if (this.selectedIndex == -1) return;
                var s1_curr_val = this.options[this.selectedIndex].value;
                $.each(options.SchoolSelectData, function(k, v) {
                    if (s1_curr_val == v.Sval) {
                        if (v.items) {
                            appendOptionTo(_thisnext, "請選擇", "", options.defaultv2);
                            $.each(v.items, function(k, v) {
                                appendOptionTo(_thisnext, v.roomName, v.Rval, options.defaultv2);
                            });
                        }
                    }
                });

            }).change();

            function appendOptionTo($o, k, v, d) {
                var $opt = $("<option>").text(k).val(v);
                if (v == d) {
                    $opt.attr("selected", "selected");
                }
                $opt.appendTo($o);
            }

        });
    };
})(jQuery);

function RfShowMeSchool() {

    var scTextID = $.cookie('hahahascSchool');
    if (scTextID == undefined) {
        return;
    }

    $("#SchoolId").empty();
    $.ajaxSetup({
        async: false
    });
    var MySchoolSelectData;
    $.getJSON("/UserCenter/user/GetSchoolSelectList?callback=" + Math.random(), function (data) {
        MySchoolSelectData = data;
    });
    var Schooldefaults = {
        NextSelId: '#DormsId',
        defaultv1: '',
        defaultv2: '',
        SchoolSelectData: MySchoolSelectData
    };

    $('#SchoolId').Schoolselected(Schooldefaults);
}

後臺讀取json資料集：

public string GetSchoolSelectList()
        {
            var schoolCode = CookieUtil.Get("scSchool").Trim();
            var _s = _schoolService.GetSchools(schoolCode);
            var _d = _dormsService.GetDorms();
               List<Object> alljson = new List<object>();
 
            foreach (var o in _s)
            {
                List<Object> roommate = new List<object>();
                var _dbySchool = _d.Where(a => a.SCHOOLPID.Trim() == o.SCHOOLID);
                foreach (var dormSelectModel in _dbySchool)
                {
               
                    roommate.Add(new
                        {
                            roomName = dormSelectModel.Text,
                            Rval = dormSelectModel.Value
                        });
                    }
                alljson.Add(new
                {
                    schoolName = o.Text,
                    Sval = o.Value,
                    items = roommate
                });
           
            }
                  return JsonConvert.SerializeObject(alljson);
        }