Question

Given:
Multiple clients with a Service.asmx page that has some web methods that I need to connect to.

A Utility function that takes input to determine which client needs to be connected to. This is what I have so far:

public static MyServiceSoapClient SoapClientFactory(string clientCode)
{
    var binding = new WSHttpBinding(SecurityMode.Message, false);
    var remoteAddress = new EndpointAddress(
        new Uri(string.Format("http://{0}.mydomain.com/Service.asmx", clientCode)),
        new UpnEndpointIdentity("[e-mail]"));

    return new MyServiceSoapClient(binding, remoteAddress);
}

This method completes with no errors (note: I don’t know what the EndPointIdentity is so I just came up with a string to put in there… not sure if this should be in a config setting somewhere else or what?)

Problem:
While trying to make the call to the remote method, an exception is thrown and its not very descriptive (A NullReferenceException). Here’s the code:

// point to the correct Service.asmx url.
var client = Util.SoapClientFactory(clientCode);

// now make the soap call.
var result = client.GetSomeStuff(someParameter); // throws the exception.

The stack trace:

System.NullReferenceException: Object reference not set to an instance of an object.
    Server stack trace:
    at System.ServiceModel.Security.IssuanceTokenProviderBase`1.DoNegotiation(TimeSpan timeout)
    at System.ServiceModel.Security.SspiNegotiationTokenProvider.OnOpen(TimeSpan timeout)
    at System.ServiceModel.Security.WrapperSecurityCommunicationObject.OnOpen(TimeSpan timeout)
    at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
    at System.ServiceModel.Security.CommunicationObjectSecurityTokenProvider.Open(TimeSpan timeout)
    at System.ServiceModel.Security.SecurityUtils.OpenTokenProviderIfRequired(SecurityTokenProvider tokenProvider, TimeSpan timeout)
    at System.ServiceModel.Security.SymmetricSecurityProtocol.OnOpen(TimeSpan timeout)
    at System.ServiceModel.Security.WrapperSecurityCommunicationObject.OnOpen(TimeSpan timeout)
    at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
    at System.ServiceModel.Channels.SecurityChannelFactory`1.ClientSecurityChannel`1.OnOpen(TimeSpan timeout)
    at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
    at System.ServiceModel.Security.SecuritySessionSecurityTokenProvider.DoOperation(SecuritySessionOperation operation, EndpointAddress target, Uri via, SecurityToken currentToken, TimeSpan timeout)
    at System.ServiceModel.Security.SecuritySessionSecurityTokenProvider.GetTokenCore(TimeSpan timeout)
    at System.IdentityModel.Selectors.SecurityTokenProvider.GetToken(TimeSpan timeout)
    at System.ServiceModel.Security.SecuritySessionClientSettings`1.ClientSecuritySessionChannel.OnOpen(TimeSpan timeout)
    at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
    at System.ServiceModel.Channels.ServiceChannel.OnOpen(TimeSpan timeout)
    at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
    at System.ServiceModel.Channels.ServiceChannel.CallOpenOnce.System.ServiceModel.Channels.ServiceChannel.ICallOnce.Call(ServiceChannel channel, TimeSpan timeout)
    at System.ServiceModel.Channels.ServiceChannel.CallOnceManager.CallOnce(TimeSpan timeout, CallOnceManager cascade)
    at System.ServiceModel.Channels.ServiceChannel.EnsureOpened(TimeSpan timeout)
    at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
    at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs)
    at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
    at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)    Exception rethrown at [0]:
    at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
    at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
    at ... my function call. (i.e. client.GetSomeStuff(someParameter) )

Answer 1

I found the answer to my problem. What I do is I create a Soap client using the default constructor (this always works but then im stuck with the Uri that I’ve configured during development) What I do then is set the Endpoint‘s Address property it worked like a charm!

var client = new MySoapClient();

// this can also be set using Web.config parameter now or a value stored in a database etc.
client.Endpoint.Address = new EndpointAddress("http://localhost:3000/Service.asmx");
return client;