Call External Method

        <p>In a workflow, to call the external method, you need the following ready.</p>
        <ul>
        <li>The workflow need a interface marked with ExternalDataExchange. In the callExternalMethodActivity node, you need to configure the InterfaceType, MethodName, MethodInvoking, and what value to be used as passed-in parameter.
        </li>

        <li>
        In workflow host, you need to config the workflow runtime to service the ExternalService. When a workflow instance execute an callExternalMethodActivity, it will ask the workflow runtime to supply a service.
        </li>
        </ul>


        <pre data-sub="prettyprint:_">
        //workflow definition
        [ExternalDataExchange]
        public interface ICustomerService
        {
        void SendCustomerData(string customerName);
        }

        //host enviroment code
        public class CustomerService : ICustomerService
        {

        public void SendCustomerData(string customerName)
        {
        Console.WriteLine(customerName);
        }
        }

        ExternalDataExchangeService xchangeSvc = new ExternalDataExchangeService();
        workflowRuntime.AddService(xchangeSvc);
        CustomerService custSvc = new CustomerService();
        xchangeSvc.AddService(custSvc);


        </pre>