WCF REST服务返回错误：远程服务器返回错误：（400）错误的请求

Question

I have call Rest WCF Service from a project like below

 userAlias = "test";
                var url = new StringBuilder();
                url.Append(
                    string.Format("https://webdemo-t.orioninc.com:8443/Services/2012v2/TestService.svc/AddAttachment?User={0}&Engagement={1}&FileName={2}&DocumentTrasferID={3}&fileSize={4}&ActivityName={5}",userAlias, engagementName, fileName, documentTranferId, fileSize, activityName));
                WebRequest request = WebRequest.Create(url.ToString());
                CurrentUrl = url.ToString();
                var networkCredential = new NetworkCredential("jame", "test", "company");
                request.Credentials = networkCredential;
                WebResponse response = request.GetResponse();
                Encoding encoding = Encoding.GetEncoding(1252);
                var responseStream = new StreamReader(response.GetResponseStream());
                string responseResult = responseStream.ReadToEnd();
                responseStream.Close();
                Console.WriteLine(responseResult);

while calling these service i got exception The remote server returned an error: (400) Bad Request. When i try to return a normal string in the WCH implementation method i got the webresponse result correctly.How can i resolve this error?

WCF Implementation Method

  public string AddAttachment(string User, string Engagement, string FileName, string DocumentTrasferID, string fileSize, string ActivityName)
    {
        dynamic _Trackerfaccade = new KPMG.EauditEmailService.Facade.EAppEmail();
        string Result = _Trackerfaccade.AddAttachment(User, Engagement, FileName, DocumentTrasferID, fileSize, FileName);
        return Result;
    }

Operation Contract

     [OperationContract]

   [WebGet(UriTemplate = "/AddAttachment?User={userAlias}&Engagement={engagementName}&FileName={FileName}&DocumentTrasferID={documentTranferId}&fileSize={fileSize}&activityName={activityName}", RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json)]
    string AddAttachment(string userAlias, string engagementName, string documentTranferId,string fileName,string fileSize,string activityName);

Answer 1

"/AddAttachment?User={0}&Engagement={1}&FileName={2}&DocumentTrasferID={3}&fileSize={4}&ActivityName={5}"

"/AddAttachment?userAlias={userAlias}&engagementName={engagementName}&documentTranferId={documentTranferId}&fileName={fileExtension}&fileSize={fileSize}&activityName={activityName}"

url pattern and real url are not same, your request can't found this method