Jquery post和unobtrusive ajax验证不工作mvc 4

在 jquery回发上,如果模型状态无效,我想使用jquery unobtrusive验证显示验证错误消息.我创建了一个示例应用程序.应用程序中的viewmodel如下所示

public class CityModel
{
    public int Id { get; set; }

    [display(Name = "City")]
    [required(ErrorMessage = "City is required")]
    public string City { get; set; }
}

并且控制器具有以下操作方法

public ActionResult City()
    {
        var cities = GetCities();

        return View(cities);
    }

    [HttpPost]
    public ActionResult SaveCity(CityModel cityModel)
    {
        if (ModelState.IsValid)
        {
            //Save City
            return null;
        }
        else
        {
            return View();
        }
    }

public List<CityModel> GetCities()
    {
        var citiesList = new List<CityModel>
        {
            new CityModel() {Id = 1,City = "London"},new CityModel() {Id = 2,City = "New York"}
        };
        return citiesList;
    }

这些观点有以下标记

@model List<CityModel>
<h2>Cities</h2>

@Html.ValidationSummary(true)
@using (@Html.BeginForm(null,null,FormMethod.Post,new { id = "frmSite",name = "frmSite" }))
{
@Html.EditorForModel()

<input type="submit" name="Sumbit" onclick=" SaveCity(); return false; " />
}

<script>
function SaveCity() {       
    $.ajax({
        type: "POST",url: "/Home/SaveCity",contentType: "application/html; charset=utf-8",data: {
            Id: $('.cityId').val(),City: $('.cityName').val()
        },success: function (data) {
        }

    });
}   
 </script>

编辑器模板看起来像

@model CityModel
<table class="table">
    <tr>
        <td>
            @Html.TextBoxFor(x => x.Id,new {@class = "cityId"})
        </td>
    </tr>
    <tr>
        <td>
            @Html.TextBoxFor(x => x.City,new {@class = "cityName"})
            @Html.ValidationMessageFor(x => x.City)
        </td>
    </tr>
</table>

我检查了< script src =“/ Scripts / jquery-1.10.2.js”>< / script> < script src =“/ Scripts / jquery.validate.js”>< / script> < script src =“/ Scripts / jquery.validate.unobtrusive.js”>< / script>包含在页面中< add key =“UnobtrusiveJavaScriptEnabled”value =“true”/>存在于Web配置文件中

function SaveCity() {

    $.validator.unobtrusive.parse($form);
        $form.validate();
        if ($form.valid()) {

        $.ajax({
            type: "POST",contentType:"application/json; charset=utf-8",City: $('.cityName').val()
            },success: function (data) {
            }

        });

    }
}

public dovalidation(e)
{
        if (e.data != null) {
            $.each(e.data,function (key,value) {
                $errorSpan = $("span[data-valmsg-for='" + key + "']");
                $errorSpan.html("<span style='color:red'>" + value + "</span>");
                $errorSpan.show();
            });
        }
}

$.each($form.validate().errorList,value) {
            $errorSpan = $("span[data-valmsg-for='" + value.element.id + "']");
            $errorSpan.html("<span style='color:red'>" + value.message + "</span>");
            $errorSpan.show();
        });