I have a non-serializable object that I would like to access from a separate process. I've looked around and it seems the only viable option is to use WCF but I'm not sure how to do this as I'm new to WCF. If I create a WCF service, how do I 'hook' the WinForm into the various events in the WCF service? For example, the user communicates with the WCF service directly and I would likemy WinForm client to be notified. How would I be able to know when the user has done something with the WCF service and have the WinForm client pick up on that?
A way to achieve what you are looking for is to implement a callback contract on your service. Then your win-forms app would be able to "subscribe" to events fired on the service (such as modifications to your object).
To do this you implement a service contract with a callback contract:
[ServiceContract]
public interface IMyService_Callback
{
[OperationContract(IsOneWay = true)]
void NotifyClients(string message);
}
[ServiceContract(CallbackContract = typeof(IMyService_Callback))]
public interface IMyService
{
[OperationContract]
bool Subscribe();
}
You then implement your service:
[ServiceBehavior(InstanceContextMode = InstanceContextMode.Single, ConcurrencyMode = ConcurrencyMode.Reentrant)]
public class MyService : IMyService
{
private List<IMyService_Callback> callbacks;
public MyService()
{
this.callbacks = new List<IMyService_Callback>();
}
private void CallClients(string message)
{
callbacks.ForEach(callback => callback.NotifyClients(message));
}
public bool Subscribe()
{
var callback = OperationContext.Current.GetCallbackChannel<IMyService_Callback>();
if (!this.callbacks.Contains(callback))
{
this.callbacks.Add(callback);
}
// send a message back to the client
CallClients("Added a new callback");
return true;
}
}
In your winforms client you only need to implement the callback method:
[CallbackBehavior(ConcurrencyMode = ConcurrencyMode.Reentrant, UseSynchronizationContext = false)]
public partial class ServiceClient : Form, IMyService_Callback
{
// Sync context for enabling callbacks
SynchronizationContext uiSyncContext;
public ServiceClient()
{
InitializeComponent(); //etc.
uiSyncContext = SynchronizationContext.Current;
// Create proxy and subscribe to receive callbacks
var factory = new DuplexChannelFactory<IMyService>(typeof(ServiceClient), "NetTcpBinding_IMyService");
var proxy = factory.CreateChannel(new InstanceContext(this));
proxy.Subscribe();
}
// Implement callback method
public void NotifyClients(string message)
{
// Tell form thread to update the message text field
SendOrPostCallback callback = state => this.Log(message);
uiSyncContext.Post(callback, "Callback");
}
// Just updates a form text field
public void Log(string message)
{
this.txtLog.Text += Environment.NewLine + message;
}
}
Config for service:
<system.serviceModel>
<services>
<service name="TestService.MyService" behaviorConfiguration="Normal">
<endpoint
address="net.tcp://localhost:8000/MyService"
contract="TestService.IMyService"
binding="netTcpBinding" />
</service>
</services>
<behaviors>
<serviceBehaviors>
<behavior name="Normal" >
<serviceDebug includeExceptionDetailInFaults="true"/>
</behavior>
</serviceBehaviors>
</behaviors>
</system.serviceModel>
Config for client
<system.serviceModel>
<client>
<endpoint address="net.tcp://localhost:8000/MyService"
binding="netTcpBinding"
contract="TestService.IMyService"
name="NetTcpBinding_IMyService">
</endpoint>
</client>
</system.serviceModel>
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