Question

I have a bizarre problem that is doing my head in.

I have the following classes defined in a single project:

public abstract class AbstractUnitModel {        public void executeRemoteModel(){}  }  //this class also implements a seperate interface, but I dont think that is the issue public class BlastFurnaceUnitModel : AbstractUnitModel, IUnitModel {} 

Now if I try something like this, it works as expected:

class Class1 {      public void method1() {          BlastFurnaceUnitModel b = new BlastFurnaceUnitModel();         method2(b);     }      public void method2(AbstractUnitModel a) {}   } 

Now I have another project that exposes a web method. This method takes an AbstractUnitModel and executes it remotely, then sends the results back to the client. So on the server I have this:

 [WebMethod]  public AbstractUnitModel remotelyExecuteUnitModel(UnitModelWrapperInterface.AbstractUnitModel unitModel)         {             unitModel.executeRemoteModel();            return unitModel;           } 

And on the client I have this:

   public void remoteExecution() {                  var unitModelWebService = new UnitModelRemoteServer.RemoteModelExecutionWebService();                 unitModelWebService.remotelyExecuteUnitModelCompleted += new UnitModelRemoteServer.remotelyExecuteUnitModelCompletedEventHandler(remoteExecutionCompleted);                 unitModelWebService.remotelyExecuteUnitModelAsync(this.remoteBF);             } 

But my project will not compile, and I get these errors: Error 109 The best overloaded method match for ‘CalibrationClient.UnitModelRemoteServer.RemoteModelExecutionWebService.remotelyExecuteUnitModelAsync(CalibrationClient.UnitModelRemoteServer.AbstractUnitModel)’ has some invalid arguments

Error 110 Argument ‘1’: cannot convert from ‘UnitModelWrapperInterface.BlastFurnaceUnitModel’ to ‘CalibrationClient.UnitModelRemoteServer.AbstractUnitModel’

I can not figure out why this is happening. I have references in the server project to the namespace where AbstractUnitModel is defined. The only thing that looked a little funny to me is that it is using AbstractUnitModel from the ‘CalibrationClient’ namespace rather than the UnitModelWrapperInterface. It seems when VS generates the proxy for a webservice on the client it creates a partial abstract implementation of AbstractUnitModel. Is this the source of my problem? If so, how might I go about fixing it?

edit for solution: As pointed out, the client needs to know about all classes that could be sent across the wire. I ended up solving this by removing the generated proxy classes and referencing the common library. Not ideal but good enough in this situation.

Answer 1

You might try [XmlInclude]:

[XmlInclude(typeof(BlastFurnaceUnitModel))] public abstract class AbstractUnitModel {...} 

Worth a try, at least…

(edit) Or at the method level:

[WebMethod(), XmlInclude(typeof(BlastFurnaceUnitModel))] public AbstractUnitModel remotelyExecuteUnitModel(...) {...} 

(less sure about the second)