What is client base class , how to use it? - wcf

I am just curious to know that what is ClientBase class in WCF, and how can i use it.
I surfed the internet and i found that this class is used to create proxies to call service methods , but no example.
Please anyone explain it with example , it will help me undestand this class...

It's the base class for your client proxies being generated by either "Add Service Reference", the svcutil.exe command line utility, or by your custom code if you don't want to use any of those methods.
It's a generic type that takes the generated client-copy of the service contract as its type parameter.
It can be extended, if you wish to do so - e.g. see IDesign's download page for a few samples of what can be done, things like:
AsyncClientBase for safe asynchronous calls
HeaderClientBase for simplified support of custom headers in your messages
Marc

It's there for autogenerated proxies which are created when service references are added to your project, not really for your own use.

Related

MEF and Wcf client proxy

I'm wondering if it is possible to EXPORT an WCF client proxy to use IOC with MEF. And how to do that ?To make the wcf client proxy i used "add service reference". Any suggestions ?
Thanks for help.
Since the class is generated, you have two solutions :
1) you can edit the class and add the MEF export attribute, but it's not a good practice to modify generated classes
2) you can copy the generated class and create a new one with that, on which you have a total control and can add the MEF export attribute.
The client class generated when you add the service reference is marked as Partial. Just create a second definition in a non-generated file and add the ExportAttribute to that.
This is another solution. ... exposing the service functionality as a shared service.

Operation Contract with Different Source or Action Url

Our third party API provides two different web services but have identical methods, models. Nevertheless they only differ on URIs (Web Service Path, Action Path [Operation Contract].
So I have decided to:
Generate the code from their wsdl using VS.
Edit the namespacing to use the same and to be "Common" and not use the service reference instead i use the Reference.cs edited code.
Create a new proxy that will handle the correct URI of the service to use (wrapped the Reference.cs inside of it).
Now, I having an issue with the "Method1", because they have different Action Name. Having an exception of:
"Server did not recognize the value of
HTTP Header SOAPAction:
http://www.api.com/service/Method1"
I just notice that it the correct action name is: http://www.api.com/service1/Method1
The question now is, is there any configuration or behavior that i can use to correct the action name for each method for each service?
Or as long as they keep on adding contracts for each implementation of the API, i should also keep on adding the contracts for each, and just use the ChannelFactory for this?
Please help, thanks.
I ended up directly using the ChannelFactory when faced with the same problem
In my implementation, I had a base interface that had all the common methods to the 2 APIs. Then I had 2 seperate intefaces - one for each 3-rd party API version - that inherits from the base interface and adds methods and [OperationContract] attributes that varied between the two implementations.
When instantianting ChannelFactory<> I used one of the child interfaces. Helped to keep the consumer code clean and maintainable

DataTable not accepted by svcutil - WCF Service

I'm having very strange issue with my WCF Service Proxy client generated by "svcutil.exe" . My WCF Service works very fine if I don't have a function that returns DataTable. As soon as I add a method that returns a DataTable the client generated by svcutil.exe is behaving very strangely. The Interface is no longer found and client is not able to call the service. But if I add as a Service Reference its working very smoothly. I know its not a good habit to use DataTable as a return type but I need to. I cannot use the Service Reference :-( Any idea why its behaving or what I'm missing!!!
Have a look at the DataTableSurrogate class. It is used by the SyncFramework for serialization and really easy to use.
MSDN DataTableSurrogate
You shouldn't really serialize datasets, instead you should use datamodels and keep anything to do with datasets, tables, readers etc on your backend & in the business layer.
But.. if you want to do so you need to add the following "include" in svcutil, which is causing your issue. (Tells to reuse the types defined in System.Data.dll and not generate them in the proxy)
/r:C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\System.Data.dll

Unable to get WCF Test client to test WCF Service Library

I am attempting to replace a WSE service with the WCF equivalent where the WSDL is provided externally.
First, I used svcutil and wsdl to generate all the service and client classes (ATP, I'm only concerned with the service implementation.) I generated an empty WCF Service Library project and replaced/renamed the IService1.cs with a class named for the interface ServiceContractAttribute generated. I then renamed the implementation class Service1.cs with the name of the implementation-class JINDEXWcfListener.cs. I removed the generated code from this class and created class definition JINDEXWcfListener:[interface name].
The tool auto-generated the implementation of the interface. I used the single method adorned with [OperationContractAttribute] to put my local implementation code. I modified the default app.config generated to adjust the contract and service names as required.
When I start debug, I can see that the service is starting in the WTC. However, when the single operation is exposed, the is a red dot with a yellow question mark in front of the operation name. When I RC on the op name, I get "This operation is not supported in WCF Test client" with no additional information. What is wrong?
WCFTestClient has quite a few limitations. I have fought "problems" for several hours that later turned out to be just WCFTestClient problems. Complex objects can give you a lot of grief, also any custom lists, etc such as a custom implementation of the IList interface. Try out WcfStorm. I think they have a free version and a trial version.

Simpler Explanation of How to Make Call WCF Service without Adding Service Ref

In Understanding WCF Services in Silverlight 2, the author, David Betz, explains how to call a web service without adding a service reference in the client application. I have a couple of weeks experience with WCF, so the article was over my head. In particular, although the author gave a lot of code snippets, but does not say what goes where. In the article, he provides two different code snippets for the web.config file, but does not clarify what's going on.
Looking at the source code there are four projects and two web.config files.
So far, I have been using the standard Silverlight project configuration of one project for the web service and one for the Silverlight client.
Firstly, does the procedure described in the article work with the standard two project configuration? I would think it would.
Secondly, does anyone know of a simpler example? I am very interested in this, but would like to either see source code in the default two project setup which is generated when a new Silverlight project is made, or find a step by step description of how to do this (eg, add a class called xxx.cs and add this code..., open web.config and add these lines...)
Many thanks
Mike Thomas
First, a little philosophy...
If you are a consumer of a WCF service that you did not write, adding a service reference to your client is really the only mechanism you have to enable interaction with that WCF service. Otherwise, you have no way of knowing what the service contract looks like, much less its data and message contracts.
However, if you are in control of both the client and the WCF service itself, adding a service reference to the client is a nice convenience, but I've recently been convinced not to use it. For one, it becomes a nuisance after the first few times you change your contract to remember to update your service reference. And in my case, I have several different C# projects that are consuming the WCF service, so I have to remember to update each one of them. Second, creating a service reference duplicates the contract definitions that are already defined in your WCF service. It is important to understand the implications of this.
Let's say your WCF defines the following type.
[DataContract]
public class Person
{
[DataMember] public string FirstName {get; set;}
[DataMember] public string LastName {get; set;}
}
When you add a service reference to your client, the metadata associated with this class is retrieved through the metadata exchange (MEX) endpoint, and an exact replica of this class is created on the client side that your client "compiles" against. So your WCF service has a definition of the Person class, and so does your client, but they are two different, distinct class definitions.
Given this, it would make more sense to abstract the Person class into a separate assembly that is then shared between the WCF service and the client. The added benefit is that when you change the contract definitions within this shared assembly, you no longer have to update the service reference within the client because it is already referencing the shared assembly. Does that make sense?
Now to your question. Personally, I've only used WCF within C# projects, not Silverlight. However, I do not think things are radically different. Given that, I would suggest that you watch the Extreme WCF video at dnrTV. It gives a step-by-step guide for how to bypass the service reference feature.
Hope this helps.
Let me try - I'm not an expert at Silverlight development, so bear with me if I say something that doesn't apply to Silverlight :-)
As Matt Davis mentioned, the "usual" use case is this: you add a service reference to a given service URL. In doing so, Visual Studio (or the command-line tool svcutil.exe) will interrogate the service and grab its metadata - information that describes the service, all the available methods to call, what parameter they expect etc. From this, it will generate a class for you (usually called the "client" or "client proxy"), which you as a client (=service consumer) will use to call the service. You can have this client proxy class generated inside your "normal" Silverlight client project, or you could possibly create your own "service adapter" class library, esp. if you will be sharing that client proxy code amongst several Silverlight projects. How things are structured on the server side of things is totally irrelevant at this point.
As Matt D. also mentioned, if you do it this way, you're getting copies of the service, its methods, and its data, in your client - those are identical in structure to what the server has - but they're not the same type - you on the client side have one type, the server has another (the fields and properties are identical though).
This is important to remember since the whole basic idea of WCF is message-passing - all that connects the client (you) and the server (the other end) are the messages and their structure - what method to call and what values to pass into that method. There's no other link - there's no way a server can "connect" to the client code and check something or whatever. All that gets exchanged is serialized messages (in text or binary form).
If you do control both ends, you can simplify things a bit - you can physically share the service contract (the definition what the service looks like and what methods it has to call into) and the data contract (the description of what data is being passed back and forth) on both the server side as well as the client side. In this case, you won't be adding a service reference, you won't be duplicating the service and data definitions, so things are a bit easier (but it only works if you're in control of both ends).
In this case, best practice would be to package up all that describes the service (the service interface with its methods and the data contracts) into a separate assembly (class library) on the server, which you can then copy to the client side, and reference directly from there (like any old assembly you might have). So in this case, you would typically have at least three projects in your solution:
your actual Silverlight client project
the website or web app hosting your Silverlight control for testing
the service interface assembly, which contains the service and data contracts
So there you have it - I hope I covered all the basics of what's going on, and why you would want to do one or the other thing. If you need additional info, don't hesitate to comment on this posting and let us know!
Marc