I have a net.tcp WCF service and its client, each in one assembly and sharing another assembly containing the service interface and DTOs.
The client is implemented as a proxy to the service using a Channel instantiated through ChannelFactory:
public ServiceClient : IService
{
IService _channel;
public ServiceClient()
{
_channel = new ChannelFactory<IService>("NetTcp_IService")
.CreateChannel();
}
public DTO ServiceMethod()
{
return _channel.ServiceMethod();
}
}
public class DTO
{
public IList<int> SomeList;
}
As expected, the SomeListfield of the DTO returned by the client is an array but I would like it to be converted by WCF to a List. As you may suspect from the described set-up, I don't use svcutil (or the Add Service Reference dialog for that matter), so I can't use configureType.
I don't want to modify the client proxy to instantiate the List and modify the received DTO in my client proxy because the actual implementation uses a command processor using interfaces resolved through dependency injection at run-time to avoid coupling - and this solution would do the opposite, by requiring the client to perform know service commands.
Therefore, I'm currently using the work-around which modifies the DTO to internally create the List instance:
public class DTO
{
private IList<int> _someList;
public IList<int> SomeList
{
get { return _someList; }
set {
if (value != null)
_someList = new List<int>(value);
else
_someList = new List<int>();
}
}
}
However, I'd rather avoid this. So the question is:
How can I configure the WCF deserialization so that the array is converted to the expected List?
Is there any way to configure the deserialization through the binding either in the App.config or from code upon Channel creation? Maybe through ImportOptions.ReferencedCollectionTypes or CollectionDataContract?
There are 4 ways:
Convert data to List in your save methods on Client side
Change property type:
public IList<int> SomeList;
to
public List<int> SomeList;
Approach you have shown above (changing type on assigment).
Implement IDataContractSurrogate. But you will have to apply a behaviour on client side.
I have several WCF services that use the same dataContracts to interchange data between them.
Can I have a sort of Metadata Endpoint for centralizing the management of all this schemas?
When creating a new WCF service, how can i make it to load the schemas from the Metadata Endpoint (instead of redefining them) to use inside its operationContracts?
Thanks!
As I said in the comment, I'm not sure I understand your question (at least with regards to wanting a metadata endpoint), but it sounds like you want to have the ability to reuse existing data contracts in multiple different services.
The easiest way to do that is to put the data contracts in a separate assembly (class library - DLL), and then have the services reference that assembly - they don't have to be defined inside the service itself.
Here's a trivial example (code is for illustration only, not intended to actually do anything or be a complete sample):
MyDataContracts assembly
namespace MyDataContracts
{
[DataContract]
public class DataContract1
{
}
[DataContract]
public class DataContract2
{
}
}
MyService1 assembly
using MyDataContracts;
namespace MyService1
{
[ServiceContract]
public interface IMyService1
{
[OperationContract]
DataContract1 GetSomeData(string someParm);
}
}
MyService2 assembly
using MyDataContracts;
namespace MyService2
{
[ServiceContract]
public interface IMyService2
{
[OperationContract]
void SendSomeData(DataContract1 dc);
[OperationContract]
DataContract2 GetSomeOtherData(int parm);
}
}
Of course, each of the WCF service projects will need to include a reference to the MyDataContracts assembly as well.
Now whenever you create a new service, you simply add a reference to the MyDataContracts.dll and you can reuse your data contracts in it.
I have a WCF service and I'm sharing types with a client in a shared assembly.
If the client create a derived class will it be possible to pass back the derived type to the service so that I can read the added properties through reflection ?
I tried but having issues with KnownTypes since the service don't know how to deserialize the derived type.
[Serializable]
public abstract class Car : ICar
{........
//on the client :
[Serializable]
public class MyCar : Car
{......
when passing myCar to Service I get the exception complaining about knownType but I cant add this on the server since I wont know what the client will be sending through and I want to handle extra properties through reflection.
Possible to register client types as knowntypes at runtime ?
Is this maybe the solution ?
http://blogs.msdn.com/b/sowmy/archive/2006/03/26/561188.aspx
This is not possible. Both service and client has to know what types will be sent in messages. If you want to use known type you have to define that relation to parent type on the service.
Why do you need to know added properties on the server?
I think there is a way.
I vaguely remember that when I studied WCF, I met ExtensionData which should be a mechanism to get everything that does not match the serialization of the class. for example, if you enable ExtensionData and you are in this situation
//Server
public class GenericRQ
{
public string GenericProperty {get;set;}
}
public Service GenericService
{
Public void GenericMethod(GenericRQ RQ)
{
}
}
// client
Public class MoreSpecificRQ : GenericRQ
{
public string SpecificProperty {get;set;}
}
At
Public void GenericMethod(GenericRQ RQ)
{
// the serializer adds automatically in RQ.ExtensionData everything that has come and that does not match the class GenericRQ.
}
On how to enable ExtensionData you to easily search on the web
I have a WCF service that generates loads Entity Framework objects (as well as some other structs and simple classes used to lighten the load) and sends them over to a client application.
I have changed 2 of the classes to implement an interface so that I can reference them in my application as a single object type. Much like this example:
Is it Possible to Force Properties Generated by Entity Framework to implement Interfaces?
However, the interface type is not added to my WCF service proxy client thingymebob as it is not directly referenced in the objects that are being sent back over the wire.
Therefore in my application that uses the service proxy classes, I can't cast or reference my interface..
Any ideas what I'm missing?
Here's some example code:
//ASSEMBLY/PROJECT 1 -- EF data model
namespace Model
{
public interface ISecurable
{
[DataMember]
long AccessMask { get; set; }
}
//partial class extending EF generated class
//there is also a class defined as "public partial class Company : ISecurable"
public partial class Chart : ISecurable
{
private long _AccessMask = 0;
public long AccessMask
{
get { return _AccessMask; }
set { _AccessMask = value; }
}
public void GetPermission(Guid userId)
{
ChartEntityModel model = new ChartEntityModel();
Task task = model.Task_GetMaskForObject(_ChartId, userId).FirstOrDefault();
_AccessMask = (task == null) ? 0 : task.AccessMask;
}
}
}
//ASSEMBLY/PROJECT 2 -- WCF web service
namespace ChartService
{
public Chart GetChart(Guid chartId, Guid userId)
{
Chart chart = LoadChartWithEF(chartId);
chart.GetPermission(userId); //load chart perms
return chart; //send it over the wire
}
}
Interfaces won't come across as separate entities in your WSDL - they will simply have their methods and properties added to the object that exposes them.
What you want to accomplish you can do using abstract classes. These will come across as distinct entities.
Good luck. Let us know how you decided to proceed.
Running a ServiceHost with a single contract is working fine like this:
servicehost = new ServiceHost(typeof(MyService1));
servicehost.AddServiceEndpoint(typeof(IMyService1), new NetTcpBinding(), "net.tcp://127.0.0.1:800/MyApp/MyService1");
servicehost.Open();
Now I'd like to add a second (3rd, 4th, ...) contract. My first guess would be to just add more endpoints like this:
servicehost = new ServiceHost(typeof(MyService1));
servicehost.AddServiceEndpoint(typeof(IMyService1), new NetTcpBinding(), "net.tcp://127.0.0.1:800/MyApp/MyService1");
servicehost.AddServiceEndpoint(typeof(IMyService2), new NetTcpBinding(), "net.tcp://127.0.0.1:800/MyApp/MyService2");
servicehost.Open();
But of course this does not work, since in the creation of ServiceHost I can either pass MyService1 as parameter or MyService2 - so I can add a lot of endpoints to my service, but all have to use the same contract, since I only can provide one implementation?
I got the feeling I'm missing the point, here. Sure there must be some way to provide an implementation for every endpoint-contract I add, or not?
You need to implement both services (interfaces) in the same class.
servicehost = new ServiceHost(typeof(WcfEntryPoint));
servicehost.Open();
public class WcfEntryPoint : IMyService1, IMyService2
{
#region IMyService1
#endregion
#region IMyService2
#endregion
}
FYI: I frequently use partial classes to make my host class code easier to read:
// WcfEntryPoint.IMyService1.cs
public partial class WcfEntryPoint : IMyService1
{
// IMyService1 methods
}
// WcfEntryPoint.IMyService2.cs
public partial class WcfEntryPoint : IMyService2
{
// IMyService2 methods
}
I'm currently faced with the same problem, and have decided to go with the implementation below. I'm not sure if there are any performance issues with having this many service contracts, but in my final implementation I will probably have about 10 - 15 service contracts, thus about 10-15 ServiceHosts.
I am hosting all my WCF services inside a single Windows Service.
private void PublishWcfEndpoints()
{
var mappings = new Dictionary<Type, Type>
{
{typeof (IAuthenticationService), typeof (AuthenticationService)},
{typeof(IUserService), typeof(UserService)},
{typeof(IClientService), typeof(ClientService)}
};
foreach (var type in mappings)
{
Type contractType = type.Key;
Type implementationType = type.Value;
ServiceHost serviceHost = new ServiceHost(implementationType);
ServiceEndpoint endpoint = serviceHost.AddServiceEndpoint(contractType, ServiceHelper.GetDefaultBinding(),
Properties.Settings.Default.ServiceUrl + "/" + contractType.Name);
endpoint.Behaviors.Add(new ServerSessionBehavior());
ServiceDebugBehavior serviceDebugBehaviour =
serviceHost.Description.Behaviors.Find<ServiceDebugBehavior>();
serviceDebugBehaviour.IncludeExceptionDetailInFaults = true;
log.DebugFormat("Published Service endpoint: {0}", Properties.Settings.Default.ServiceUrl);
serviceHost.Open();
serviceHosts.Add(serviceHost);
}
}
Feel free to comment on this type of set up, and if there are any issues with it, especially performance-related.
This answer is a further response to the comment in the accepted answer from chilltemp.
Sam, You really should determine why you need 10-50 contracts and try to find another solution. I looked over Juval Lowy's WCF Coding Standards (found on http://www.idesign.net/) and found the following references:
3 Service Contracts
[...]
Avoid contracts with one member.
Strive to have three to five members per service contract.
Do not have more than twenty members per service contract. Twelve is probably the practical limit.
He doesn't mention a limit on contract implementations (that I can find) but I can't imagine him viewing 50 contracts on a service as anything resembling a best practice. One solution I have found that works well is to use member sharing for similar functions.
For instance, if you are using the WCF service to perform mathematics on 2 values you might have 4 members on the service side: Add(x,y), Subtract(x,y), Multiply(x,y), Divide(x,y). If you combine these into a more generic member and use an object to pass the needed data you can easily reduce your member count and increase scalability. Example: PeformCalculation(obj) where obj has x, y, and action (add, subtract, multiply, divide) properties.
Hope this helps.
I found another solution to for this issue by using a the RoutingService class. Each contract must still be hosted in it's own ServiceHost, but there can be a RoutingService sitting on top of all of them - and presenting them over an unified "endpoint". I've also written a codeproject article about it. The example code is also available on Bitbucket.
chili's answer will work if you are ok with the contracts being shared by the service. If you want them to be separated try this:
host1 = new ServiceHost(typeof(MyService1));
host2 = new ServiceHost(typeof(MyService2));
host1.Open();
host2.Open();
public class MyService1 : IMyService1
{
#region IMyService1
#endregion
}
public class MyService2 : IMyService2
{
#region IMyService2
#endregion
}
Edit: As Matt posted, this would require multiple endpoints for each service/contract
No-one documented enpoints. Whe used more than one (as a group, from common url, for example http) must use the same binding instance (not more), i.e.
Your sample:
servicehost = new ServiceHost(typeof(MyService1));
servicehost.AddServiceEndpoint(typeof(IMyService1), new NetTcpBinding(), "net.tcp://127.0.0.1:800/MyApp/MyService1");
servicehost.AddServiceEndpoint(typeof(IMyService2), new NetTcpBinding(), "net.tcp://127.0.0.1:800/MyApp/MyService2");
servicehost.Open();
should be only one new Binding(), I tested over http.
servicehost = new ServiceHost(typeof(MyService1));
BasicHttpBinding binding = new BasicHttpBinding();
servicehost.AddServiceEndpoint(typeof(IMyService1),binding , "http://127.0.0.1:800/MyApp/MyService1");
servicehost.AddServiceEndpoint(typeof(IMyService2), binding, "http://127.0.0.1:800/MyApp/MyService2");
servicehost.Open();
I agree totally with partial class implementing few contracts in few files.
What about splitting it up with a base address and multiple services/contracts below it?
I am not behind a developmachine right now but something like:
http://myserver/myservices/serviceA
http://myserver/myservices/serviceB
http://myserver/myservices/serviceC
Each service implementing its own ServiceContract.
You can change
public class WcfEntryPoint : IMyService1, IMyService2
to
public partial class WcfEntryPoint : IMyService1
public partial class WcfEntryPoint : IMyService2
Example
Did I miss something, or is the simplest solution not mentioned here? The simplest solution is this: Don't use multiple interfaces for the Web Service.
But that doesn't mean you can still have your interfaces separated. This is why we have Interface inheritance.
[ServiceContract]
public interface IMetaSomeObjectService : ISomeObjectService1, ISomeObjectService2
{
}
The Meta interface inherits from all the other interfaces.
[ServiceContract]
public interface ISomeOjectService1
{
[OperationContract]
List<SomeOject> GetSomeObjects();
}
[ServiceContract]
public interface ISomeOjectService2
{
[OperationContract]
void DoSomethingElse();
}
Then the service just has the Meta interface.
public class SomeObjectService : IMetaSomeObjectService
{
public List<SomeOject> GetSomeObjects()
{
// code here
}
public void DoSomethingElse()
{
// code here
}
}