将类对象传递给WCF服务c＃wp8

Question

我正在尝试通过Post Async Method传递类对象

public async void SAveDetails(clsPickList obj)
{
    using (HttpClient client = new HttpClient())
    {
        HttpContent content = new StringContent(JsonConvert.SerializeObject(obj));
        content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
        var result = await  client.PostAsync("http://-Port-/-svc file name-/InsertUserDetails", content) ;
        result.EnsureSuccessStatusCode();
        if (result.Content != null)
        {
            var responseContent = await result.Content.ReadAsStringAsync();
        }
    }
}

至

[OperationContract]
[WebInvoke(Method = "POST",
    ResponseFormat = WebMessageFormat.Json,
    RequestFormat = WebMessageFormat.Json,
    BodyStyle = WebMessageBodyStyle.Wrapped,
    UriTemplate = "InsertUserDetails")]
string InsertUserDetails(Model.clsPickList obj);

并如下插入对象值

public string InsertUserDetails(Model.clsPickList obj)
{  
    cmd.Parameters.AddWithValue("@UserName", obj.UserName);
    cmd.Parameters.AddWithValue("@Password", obj.Password);
}

但是当我通过WP8访问链接时，它返回404错误。 由于我是WCF的新手，所以我非常感谢任何人的帮助。

提前致谢..