c# - How to add cross domain support to WCF service

Question

I'm trying to allow POST requests from my javascript app hosted at localhost:80 to a WCF REStful service hosted at a different port, but somehow it doesn't work. I've tried adding custom properties to the header, as well as adding it programatically in my service's JSONData method but I'm still getting '405 Method not allowed' in my response. What is the proper approach here ?

This is my interface :

namespace RestService
{
    public class RestServiceImpl : IRestServiceImpl
    {
        #region IRestServiceImpl Members

        public string JSONData()
        {
            HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "*");
            return "Your POST request";
        }

        #endregion
    }
}

and the service code :

using System.ServiceModel;
using System.ServiceModel.Web;
using System.Web.Script.Services;

namespace RestService
{

    [ServiceContract]
    public interface IRestServiceImpl
    {
        [OperationContract]
        [ScriptMethod]
        [WebInvoke(Method = "POST",
            ResponseFormat = WebMessageFormat.Json,
            BodyStyle = WebMessageBodyStyle.Bare,
            UriTemplate = "export")]
        string JSONData();
    }
}

And finally the config :

<?xml version="1.0"?>
<configuration>

  <system.web>
    <compilation debug="true" targetFramework="4.0" />
  </system.web>
  <system.serviceModel>
    <services>
      <service name="RestService.RestServiceImpl" behaviorConfiguration="ServiceBehaviour">
        <endpoint address ="" binding="webHttpBinding" contract="RestService.IRestServiceImpl" behaviorConfiguration="web">
        </endpoint>
      </service>
    </services>

    <behaviors>
      <serviceBehaviors>
        <behavior name="ServiceBehaviour">
          <serviceMetadata httpGetEnabled="true"/>
          <serviceDebug includeExceptionDetailInFaults="false"/>
        </behavior>
      </serviceBehaviors>
      <endpointBehaviors>
        <behavior name="web">
          <webHttp/>
        </behavior>
      </endpointBehaviors>
    </behaviors>
    <serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
  </system.serviceModel>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
    <httpProtocol>
      <customHeaders>
         <add name="Access-Control-Allow-Origin" value="*" />
      </customHeaders>
</httpProtocol>  
  </system.webServer>

</configuration>

Answer 1

This worked better for me than the Web.config version:

Create a Global.asax

Add this method to the Global.asax.cs:

using System.Web;

namespace StackOverflow
{
    public class Global : System.Web.HttpApplication
    {
        protected void Application_BeginRequest(object sender, EventArgs e)
        {
            HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "*");
            if (HttpContext.Current.Request.HttpMethod == "OPTIONS")
            {
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Methods", "GET, POST");
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Headers", "Content-Type, Accept");
                HttpContext.Current.Response.AddHeader("Access-Control-Max-Age", "1728000");
                HttpContext.Current.Response.End();
            }
        }
    }
}

Ref: http://www.dotnet-tricks.com/Tutorial/wcf/X8QN260412-Calling-Cross-Domain-WCF-Service-using-Jquery.html