用C#做一个REST的WCF，用POST方法总是返回400错误

RT

接口协议：
[OperationContract]
        [WebInvoke(Method = "POST", UriTemplate = "/FeedBack/Submit", ResponseFormat = WebMessageFormat.Json, RequestFormat = WebMessageFormat.Json)]
        ErrorCode SubClientFeedback(FeedBack userFeedBack);

Client：
string strText;

            Uri address = new Uri("http://mobi4biz.net" + "/mobi4bizservice.svc/FeedBack/Submit");
            // Create the web request
            HttpWebRequest request = WebRequest.Create(address) as HttpWebRequest;
            // Set type to POST
            request.Method = "POST";
            request.ContentType = "application/json; charset=utf-8";
            //request.ContentType = "text/x-json";
            // Create the data we want to send
            string data = "{ \"usrID\": 1, \"FeedBackType\": 1, \"ContactName\": \"afd dfad \", \"ContactPhone\": \"123534234\", \"ContactEmail\": \"asf@asdf.com\"}";
            // Create a byte array of the data we want to send
            byte[] byteData = UTF8Encoding.UTF8.GetBytes(data);
            // Set the content length in the request headers
            request.ContentLength = byteData.Length;
            // Write data
            using (Stream postStream = request.GetRequestStream())
            {
                postStream.Write(byteData, 0, byteData.Length);
            }
            // Get response
            using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
            {
                // Get the response stream
                StreamReader reader = new StreamReader(response.GetResponseStream());
                // Console application output
                strText = strText + reader.ReadToEnd();
            }
            strText = strText + "\n";
            lblStatus.Text = strText;

我用AJAX调用也是同样的问题。
function HttpPost() {
                 var str = "{ \"usrID\": 1, \"FeedBackType\": 1, \"ContactName\": \"afd dfad \", \"ContactPhone\": \"123534234\", \"ContactEmail\": \"asf@asdf.com\"}";
                 $.ajax({
                     type: "POST",
                     contentType: "application/json",
                     url: "http://localhost:6023/Testservice.svc/FeedBack/Submit",
                     data: str,
                     success: function(data) {
                         $("#TextPost").val(data);
                     }
                 });
             }

不知道是什么问题？会不会是namespace的问题？请高手指点一下！谢谢！！！！ --------------------编程问答--------------------

--------------------编程问答-------------------- 自己顶起来！ --------------------编程问答-------------------- 你的url 地址实用可能有问题。我也遇到过类似的问题：把URL换成相对路径就好用了。据资料说是跨域问题造成。 --------------------编程问答-------------------- http://blog.csdn.net/fangxinggood/archive/2011/03/14/6247297.aspx

补充：.NET技术 ,  C#