Ajax调用错误无法检索[对象对象]

Question

我正在尝试构建一个简单的国家/地区级联下拉列表。但我得到ajax调用失败来检索状态[对象对象]。我不知道问题出在哪里。我的国家名单来自一个工作正常的viewbag。但是状态列表不起作用甚至没有达到断点GetState（）函数。请帮忙！以下是我的代码：

index.cshtml:

     <div>
     @Html.DropDownList("Country", (IEnumerable
        <SelectListItem>)ViewBag.CountryList, "Select a country")
        </div>
        <div>
    @Html.DropDownList("State", new SelectList(string.Empty, "Value", "Text"),  "--Select State--", new { style = "width:200px" })
    </div>      
       <script src="~/Scripts/jquery-1.10.2.min.js"></script>

                        <script type="text/javascript">
                            $(document).ready(function () {  

                                $("#Country").change(function () {  
                                    $("#State").empty();  
                                    $.ajax({  
                                        type: 'POST',  
                                        url: '@Url.Action("GetState")',  

                                        dataType: 'json',  

                                        data: { id: $("#Country").val() },  


                                        success: function (states) {


                                            $.each(states, function (i, 

state) {
             $("#State").append('<option value="' + state.Value + '">' +
                                                     state.Text + '</option>');
                                            });
                                        },
                                        error: function (ex) {  
                                            alert('Failed to retrieve state.' + ex);  
                                        }  
                                    });  
                                    return false;  
                                })  
                            });  
                            </script>

    HomeController:


    [HttpGet]
        public JsonResult GetState(int? id)
        {

            List<SelectListItem> list = new List<SelectListItem>();
            list.Add(new SelectListItem { Text = "--Select Country--", Value = "0" });
            list.Add(new SelectListItem { Text = "AL", Value = "1" });
            return Json(new SelectList(list, "Value", "Text", JsonRequestBehavior.AllowGet));

        }