Question

I’m trying to use WCF for the first time however I hit a problem pretty fast that I don’t understand. I haven’t changed the original structure of the auto generated code yet. I got this code to work on the website.

using ServiceReference.ServiceClient wcfClient = new ServiceReference.ServiceClient())
{
  string data = wcfClient.GetData(32);
  Label1.Text += data;
}

But when I started using this code I got in to some problem.

ServiceReference.Kund kund;

using (ServiceReference.ServiceClient wcfClient = new ServiceReference.ServiceClient())
{
    string data = wcfClient.GetDataUsingDataContract(kund);
}

I got the this error. I can’t really see any problem with the data type it’s not a string.

Cannot implicitly convert type ‘Webbshop.ServiceReference.Kund’ to ‘string’

Edit:

[ServiceContract]
public interface IService
{
    [OperationContract]
    string GetData(int value);

    [OperationContract]
    Kund GetDataUsingDataContract(Kund kund);
}

[DataContract]
public class Kund
{
    int iD;
    [DataMember]
    public int ID
    {
        get { return iD; }
        set { iD = value; }
    }
}

Answer 1

Can you show us the service contract (that IMyService interface, or whatever it’s called in your case) you have??

Typically, the sample apps that the WCF service generates will have one method GetData that returns a string, and a second method that shows how to return a complex data type

[ServiceContract]
public interface IService1
{
    [OperationContract]
    string GetData(int value);

    [OperationContract]
    CompositeType GetDataUsingDataContract(CompositeType composite);
}

Here: the second method – after your alterations – returns a Kund. Of course, if you call that second method which returns a Kund, you cannot just assign your entire Kund to a string…. you would have to do something like:

ServiceReference.Kund kund;

using (ServiceReference.ServiceClient wcfClient = new ServiceReference.ServiceClient())
{
    Kund returnedKund = wcfClient.GetDataUsingDataContract(kund);

    // then assign whatever properties from `data` you need to your string .....
    string data = returnedKund.ID.ToString();  // or something.....
}