今日在用MVC練習製作連動式下拉選單，但一直遇到一個問題，在控制器回傳資訊給前端的jquery時，下拉選單的text一直會呈現全白或者是[Object object]的情況，欲詢問這該怎麼解才好@_@ ，謝謝大家！

text出現以下狀況，但value在檢查中是有拿到值的，同時選單項目數量也是正確的，唯一問題就是text無法顯示出我要的值。

示意圖
全空白


[Object object]

VIEW

@{
    ViewBag.Title = "Index";
}

<h2>Index</h2>

<p>
   Customer @Html.DropDownList("CustomerList", (IEnumerable<SelectListItem>)ViewBag.items ,"--請選擇--", new { @class="form-control" , id="Customer"})
</p>
<p>
    Order <select name="orders" id="Orders" class="form-control"><option>----</option></select>
</p>

<script type="text/javascript" language="javascript">
<!--
    $(document).ready(function () {
        $('#Customer').change(function () { ChangeCustomer(); });
    })
        function ChangeCustomer() {
            var SelectedCustomer = $('#Customer option:selected').val();
            if ($.trim(SelectedCustomer).length > 0) {
                GetOrders(SelectedCustomer);
            }
        }

    function GetOrders(customerID) {
        $.ajax({
            url: '@Url.Action("Orders","Home")',
            data: { customerID: customerID },
            type: 'post',
            cache: false,
            async: false,
            datatype: 'json',
            success: function (data) {
                if (data.length > 0) {
                    $('#Orders').empty();
                    $('#Orders').append($('<option></option>').val('').text('--請選擇訂單--'));
                    $.each(data, function (i, item) {
                        //$('#Orders').append($('<option></option>').val(i).text.get(item));
                        $('#Orders').append($('<option>', {
                            value: i,
                            text: item
                        }));
                    })
                }
            }
        })
                }

</script>

CONTROLLER

using DropDownListProject.Models;
using DropDownListProject.ViewModels;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace DropDownListProject.Controllers
{
    public class HomeController : Controller
    {
        // GET: Home
        public ActionResult Index()
        {
            HomeModel A = new HomeModel();
            List<CustomerViewModel> mRet = new List<CustomerViewModel>();
            mRet = A.GetCustomerList();

            SelectList items = new SelectList(mRet,"CUSTOMERID","CUSTOMERNAME");
            ViewBag.items = items;

            return View();
        }

        [HttpPost]
        public JsonResult Orders(string customerID)
        {
            HomeModel A = new HomeModel();
            List<KeyValuePair<string, string>> items = new List<KeyValuePair<string, string>>();

            //若customerID不為空且有值，則從資料庫取資料出來
            if (!string.IsNullOrWhiteSpace(customerID))
            {
                var mRet = A.GetOrderList(customerID);
                if (mRet.Count() > 0)
                {
                    foreach (var order in mRet)
                    {
                        items.Add(new KeyValuePair<string, string>(order.OrderID, string.Format("{0}",order.OrderDate)));
                    }
                }
            }
            return this.Json(items);
        }
    }
}