Can we add a service reference dynamically to a project without using add reference in visual studio. Does Wsdl Import of metadata will help in achieving this goal can some one help me in dynamically loading and attaching the service to project and use the client in wcf or suggest me a methodology in achieving this.
The .NET framework has a namespace dedicated to this called System.ServiceModel.Discovery. From a high level you use a DiscoveryClient which can locate services available for use.
To be able to locate services with the DiscoveryClient the service info needs to be sent out through the AnnouncementClient class. This class allows a service to publish announcement messages. From the documentation:
An announcement message contains information about the service such as its fully-qualified contract name, any scopes that the service is operating in as well as any custom metadata the service wants to send.
These classes should be everything you need to provide the plumbing for dynamic service discovery and usage.
If you are trying to consume existing third party endpoints (services that are not under your control) there are at least two methods provided in the .NET framework.
MetadataExchangeClient
MetadataResolver
MetadataExchangeClient will connect to a MEX/wsdl endpoint and return back a collection of objects representing the service metadata.
MetadataResolver will return the configuration for a known service if you pass it the MEX/wsdl endpoint and the type to resolve. This allows you import the connection settings without having to specifiy it up front.
To see what else is available explore the System.ServiceModel.Description namespace. It has the two classes above plus others related to dynamic service resolution.
EDIT: This was able to retrieve Metadata for me:
MetadataExchangeClient client = new MetadataExchangeClient(
new Uri("http://localhost:22948/Service1.svc?wsdl"),
MetadataExchangeClientMode.HttpGet);
var response = client.GetMetadata();
Related
I am using Biztalk UDDI V3 (stand-alone install) on a windows 2008. I have configured all services (web, database and subscription):
I successfully published a couple of services
I successfully accessed and retrieved service information from my .net console application.
My issue at this point is with the subscription service. I tried to subscribe to one of the published services only to find out that I need to create my own listener.
I followed the steps listed here. Please take a look at the section entitled "Building subscription alerts for service changes". I am confused as to what the WCF service I create is supposed to look like. The instructions state the following:
Now we create a new WCF Service project and reference this existing service library. After making sure the .svc file points to our referenced library object, and adding a valid endpoint configuration file, view our service in the web browser to ensure that it's up and running.
I find this section confusing. Not sure what public methods would the WCF service expose(if any at all) or how to expose the functionality within the service library that I just referenced from within my WCF project.
Of course, if you know of a different way to achieve what I am trying to accomplish, that also would be much appreciated.
Thank you.
This may help. I actually just wrote a complete port for Apache jUDDI's client library using .NET C#. One of the use cases is actually what you are attempting to do. Here's the rough approach used.
Generate the code from wsdl (using wsdl.exe, because svcutil doesn't like the UDDI wsdls)
Alter the interface code to have WCF bindings for the Subscription Listener class
Create an implementation of the subscription listener and handle the callbacks
Fire up the implementation using WCF's embedded service
Register your sub listener endpoint with UDDI (using the correct annotations per the spec)
Setup the subscription using your sub listener's binding template
Wait for callbacks
Here's the code
http://svn.apache.org/repos/asf/juddi/trunk/juddi-client.net/
Example
http://svn.apache.org/repos/asf/juddi/trunk/juddi-client.net/juddi-client.net-sample/org.apache.juddi.client.samples/SubscriptionCallbackExample.cs
There's also a Java version that does the exact same thing.
Allow me to explain a little better.
I have a VS2010 Solution, split into 2 projects: a WCF Web Service, and a Class Library that uses the Web Service.
The WCF Web Service is a simple logging service; namespace "LogService", service "LogService", contract "ILogService".
When you use the "Add Service Reference" utility that comes with VS2010 to add a reference to the WCF, into the consuming Class Library project, you will see that the tool correctly adds a reference to a Web Service that can be called through "LogService.LogServiceClient". No problem here.
Now, I have another Solution; this is also split into 2 projects: another WCF Web Service, and a Web Application that uses this new Web Service.
This particular Web Service provides operations performed on a database; namespace "BLService", service "BLService", contract "IBLService".
Using that very same "Add Service Reference" utility in this project, however, adds a reference whose client name is actually "BLService.IBLServiceClient". Please notice there is a "I" prepended to the service client class name. The utility seems to have decided it should use the contract's name, instead of the service's name, to create the service client class.
I don't understand why does the tool behave differently on both Solutions. I've tried checking everything I could from both, and I can't find no significative differences (to my knowledge, at least).
Do you people know why does this happen? What things should I check, and correct, in my Web project (or anywhere else in the solution) so this odd behavior does not happen anymore?
I am trying to consume a WCF web service from a .NET client application, and I think I need to be able to programmatically create endpoints, but I don't know how. I think I need to do this because, when I try to run the application, I am getting the following error:
Could not find default endpoint
element that references contract
'IEmailService' in the ServiceModel
client configuration section. This
might be because no configuration file
was found for your application, or
because no endpoint element matching
this contract could be found in the
client element.
While troubleshooting this error, I created a simple windows forms application, in which I try to consume the same web service. With this test application I can connect to the web service successfully, and I get a valid response. But, I can reproduce the exact error cited above within in my test app by removing the system.serviceModel node and all of its child nodes from the application's app.config file (I might not have to remove ALL of that section, I'm not sure). So, my first thought was that I need to add that section to the app.config file for the real app, and everything should be fine. Unfortunately, for ridiculous reasons that I won't get into here, that is not an option. So, I am left with having to generate this information in code, inside the client app.
I am hoping someone here can help me work through this, or can point me toward a good resource for this sort of problem.
Is it possible to create endpoint configurations in the client app, in code?
By default, when you do an Add Service Reference operation, the WCF runtime will generate the client-side proxy for you.
The simplest way to use it is to instantiate the client proxy with a constructor that takes no parameters, and just grab the info from the app.config:
YourServiceClient proxy = new YourServiceClient();
This requires the config file to have a <client> entry with your service contract - if not, you'll get the error you have.
But the client side proxy class generated by the WCF runtime also has additional constructors - one takes an endpoint address and a binding, for instance:
BasicHttpBinding binding = new BasicHttpBinding(SecurityMode.None);
EndpointAddress epa = new EndpointAddress("http://localhost:8282/basic");
YourServiceClient proxy = new YourServiceClient(binding, epa);
With this setup, no config file at all is needed - you're defining everything in code. Of course, you can also set just about any other properties of your binding and/or endpoint here in code.
An east way to consume a WCF service if you have a reference to the assembly which defines the interface, is using the System.ServiceModel.ChannelFactory class.
For example, if you would like to use BasicHttpBinding:
var emailService = ChannelFactory<IEmailService>.CreateChannel(new BasicHttpBinding(), new EndpointAddress(new Uri("http://some-uri-here.com/));
If you don't have a reference to the service assembly, then you can use one of the overloaded constructors on the generated proxy class to specify binding settings.
We currently have a WCF Service which is beginning to reach it's limits performance wise.
We have decided to add another server which will host another instance of the WCF Service.
We have web applications which must communicate with a specific server based on context... e.g. If the web application is dealing with objects from ServiceInstance1 then requests must be directed to ServiceInstance1's EndPoint. If the web application is dealing with objects from ServiceInstance2 then requests must be directed to ServiceInstance2's EndPoint.
I initially thought that a "Intermediate Service" or "Service Manager" could be created, the web application's Service Reference would be updated from the individual Service Instance to the "Intermediate Service" or "Service Manager" and said service would act as a "Broker" to the various Service Instances.
How is this accomplished?
I have currently added a ServiceReference to each service from the Manager however it seems that once a Service is "Referenced" it's types becomes specific to the that of the ServiceReference e.g.
ServiceInstance1's type's are all {ServiceInstance1}.
ServiceInstance2's type's are all {ServiceInstance2}.
I need the types to be the same on the web application end, so this obviously seems like the wrong way to do it.
I would also like that when methods are called on the client generated from referencing the "Intermediate Service" or "Service Manager" that the correct Service Instance is invoked, e.g.
IServiceManager.GetProjectById( {GUID} ) ->
Comes Back to ServiceManager ->
Determines which host has the project and returns the ProjectObject from the correct ServiceInstance.
Where ProjectObject is a Type Defined in ServiceInstance1 and ServiceInstance2.
I think the original service needs to have some of the DLL's pulled out so they can be referenced from the web application side and ServiceManager and a GenericWCF Client can be made.
If I am right hooray for me If someone can point me in the right direction I would appreciate it. If I am wrong can someone please scold me and show me how this is properly done!
The way to solve your problem is to create shared assembly with types used by both services. Reference this assembly on the client consuming your services (manager) and when creating proxies by Add service reference mark Reuse types from referenced assemblies.
What you are building is very simple message router. In WCF 4.0 there is additional support for routing services so you should check those features before developing your own. For WCF 3.5 MSDN magazine contains articles about building message router - part 1, part 2.
Just to Answer this and close it I wound up utilizing the Routing Strategy in .Net 4.0 and custom client class which I modeled after the generated classes from the Proxy.
Before I had the custom client ready I used the auto generated client code and I derived a class from it which allow me to change which service it was connecting to. I determined which service via a property which was made available on all service objects which were serialized.
Long story short this is working 100% as expected including the ServiceManager which can even be bypassed on certain calls which we allow.
We even have the ability to move a project from server to server during run time!
Thanks to everyone who helped! (Especially myself for actually doing the work without being spoon fed)
The easiest way to accomplish what you're trying to do is to stop generating your proxies using the server-hosted URL of the service. Instead, generate your proxies from the *.xsd and *.wsdl locally, and merely change the URL of the endpoint. Alternatively, you can use ChannelFactory<T> to generate proxies on-the-fly, and reference your interface .dll on the client side.
Once you've done that, you can use any common webserver load balancing technique to balance the load between the servers.
Not to put too fine a point on it, but Visual Studio's "Service Reference" is not useful, and should not be used, for services you develop. It's useful only for services developed externally, whose URL and contracts are likely to NEVER change. I personally have never had occasion to use it. For your own services, you should probably be using ChannelFactory<T> or a class based on ClientBase<T> to work out the proxies.
Is it possible to add a service reference in visual studio, which generates the local proxy class to call the WCF service when using the netTcpBinding?
As I understood it, the service reference method requires a WSDL to be exposed by the service, which is only supported by the http bindings no?
Perhaps, could I add the service reference locally in development, but then switch the configuration to use nettcp at runtime in production?
The reason I am asking is because I am hosting in a windows service (server 2003, so no WAS, and can't use IIS). And we are unable to change the permissions to do the HTTP namespace reservation ... so we can't use the HTTP bindings. NetTcp works, but in this specific case the object graph we're passing back and forth involves objects generated in the service by an EDMX model ... so we can't share it in a contract assembly.
Thanks in advance!
Simply add a binding using mexTcpBinding.
Is it possible to add a service reference in visual studio,
which generates the local proxy class to call the
WCF service when using the netTcpBinding?
Yes, most definitely!
As I understood it, the service reference method requires a WSDL
to be exposed by the service, which is only supported by the http bindings no?
No, definitely not - WCF metadata (either its own specific format, or exposed as WSDL / XSD files) is definitely available for all SOAP-based calls - regardless of their transport.
Can you show us what you have, in terms of server-side config? Most likely, you're just missing a little config setting or something - if we see what you have, we might be able to pinpoint that and help you more!
All bindings are exposed though WSDL. If you add the NETTCP bindings svcutil will atuo generate the client correctly. I haven't used it in the ADD reference in VS as i have always preferred to generate the class with svcutil.