Request Error: The server encountered an error processing the request

Questo errore mi si è presentato in una applicazione SharePoint 2010 in cui c'era una chiamata JavaScript ad un servizio WCF tramite una chiamata jQuery AJAX.la chiamata era di questo tipo

JavaScriptCopia

var loginName = "SGART\user1";

var jsonParam = '{'
	+ '"loginName":"' + loginName + '"'
	+ '}';

$.ajax({
    type: "POST",
    url: "/helpdesk/_vti_bin/timesheetservice.svc/CdcAndCompany",
    data: jsonParam,
    processData: false,
    cache: false,
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function (data, textStatus, jqXHR) {
        if (data.success == false) {
            var s = "";
            for (var ie = 0; ie < data.errors.length; ie++) {
                s += data.errors[ie];
            }
            lblCdc.html("Errors: " + er);
        } else {
            lblCdc.html(data.cdc);
            lblCompany.html(data.company);
        }
    },
    error: function (jqXHR, textStatus, errorThrown) {
        lblCdc.html(textStatus + " - " + errorThrown);
    }
});

ed andava sempre in errore. La variabile textStatus conteneva error e errorThrown conteneva Bad Request, errori molto generici.

Il problema era nella variabile loginName che conteneva una backslash ( \ ), una volta concatenata in jsonParam e passata al metodo dava errore.

Per risolverlo ho fatto l'escape del carattere backslash tramite il metodo replace:

JavaScriptCopia

var jsonParam = '{'
        + '"loginName":"' + loginName.replace("\\", "\\\\") + '"'
        + '}';

Lato server il WCF era questo:

<%@ ServiceHost Language="C#" Debug="true"
    Service="Sgart.HelpDesk.TimeSheetService, $SharePoint.Project.AssemblyFullName$"  
    CodeBehind="TimeSheetService.svc.cs"
    Factory="Microsoft.SharePoint.Client.Services.MultipleBaseAddressWebServiceHostFactory, Microsoft.SharePoint.Client.ServerRuntime, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>

C#: TimeSheetService.svcCopia

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
using System.ServiceModel.Web;

[BasicHttpBindingServiceMetadataExchangeEndpointAttribute]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Required)]
public class TimeSheetService : ITimeSheet
{
       public UserInfo2 HelpDeskCdcAndCompany(string loginName)
        {
            UserInfo2 result = new UserInfo2();
            try
            {
                result.LoginName = loginName;
                string company="";
                string cdc = Manager.GetCDC(loginName, out company);

                result.CDC = cdc;
                result.Company = company;

                result.Success = true;
            }
            catch (Exception ex)
            {
                result.AddError(ex);
            }
            return result;
        }
}

C#: ITimeSheet.csCopia

[ServiceContract]
    public interface ITimeSheet
    {
        [OperationContract]
        [WebInvoke(UriTemplate = "CdcAndCompany"
            , BodyStyle = WebMessageBodyStyle.WrappedRequest
            , RequestFormat = WebMessageFormat.Json
            , ResponseFormat = WebMessageFormat.Json)]
        UserInfo2 HelpDeskCdcAndCompany(string loginName);

    }

    [DataContract]
    public class ServiceStatus
    {
        public ServiceStatus()
        {
            Success = false;
            Errors = new List<string>();
            ReturnValue = -1;
        }
        [DataMember(Name = "success")]
        public bool Success { get; set; }
        [DataMember(Name = "errors")]
        public List<string> Errors { get; set; }
        [DataMember(Name = "returnValue")]
        public int ReturnValue { get; set; }

        public void AddError(string message)
        {
            Errors.Add(message);
            Success = false;
        }
        public void AddError(Exception ex)
        {
            Errors.Add(ex.Message);
            Success = false;
        }
    }

    [DataContract]
    public class UserInfo2 : ServiceStatus
    {
        [DataMember(Name = "loginName")]
        public string LoginName;


        [DataMember(Name = "cdc")]
        public string CDC;

        [DataMember(Name = "company")]
        public string Company;
    }