Coupling Issue Solution by WCF Technology - Part II

In my first post we could see different client and service contract interfaces that successfully worked in reviewed example. The differences between two interfaces were in following details:

Namespace: CustomBaseServer and CustomBaseClient – works without specify solution
Interface Name: Trading and Trading1 – solved by [ServiceContract (Name=...)]
Method Name: GetRate and GetRate1 - solved by [OperationContract(Name=...)]

So we have enough reasons to say that interfaces really diverse. But between two contacts can be additional differences worked and supported by WCF as well:

Number of methods
Number of method parameters
Name of method parameters

Example Source Code

File: ITrading.cs - Service Interface Code Snippet
namespace CustomBaseServer
{

    [ServiceContract]
    interface ITrading
    {
        [OperationContract]
        void Foo1();
 
        [OperationContract]
        void Foo2(string text);
 
        [OperationContract]
        void Foo3(
            //[MessageParameter(Name = "p1")] int x
            //,[MessageParameter(Name = "p2")] int y
            //,[MessageParameter(Name = "p3")] int z 
            int x, int y, int z);
 
        [OperationContract]
        void Foo4(double val);
 
        void Foo88(DateTime dt);
    }
}
 
 
File: ITrading.cs - Client Interface Code Snippet 
namespace CustomBaseClient
{
    [ServiceContract(Name = "ITrading")]
    interface ITrading1
    {
        [OperationContract]
        void Foo();
 
        [OperationContract]
        void Foo1();
 
        [OperationContract]
        void Foo2();
 
        [OperationContract]
        void Foo3(int y, int var2);
 
        void Foo99();
    }
}
 
 
File: Programm.cs - Client Consol Code Snippet 
namespace CustomBaseClient{
    class Program
    {
        //Run it in debug mode
        static void Main(string[] args)
        {
            Console.WriteLine("Client start...");
            var channelFactory = new ChannelFactory<ITrading1>("ITradingBasicHttp");
            //var channelFactory = new ChannelFactory<ITrading1>("ITradingWebService");
            var trading = channelFactory.CreateChannel();
 
            //ActionNotSupportedException, this method undefined in service contract
            trading.Foo();
 
            //Ok
            trading.Foo1();
 
            //Ok, but the service side gets null string
            trading.Foo2();
 
            //Ok, but service side gets only "y" parameter, x and z is initialized with
            //zero value. Even first client and second service parameter matched by
            //common ("y") name. It's work, great!   
            trading.Foo3(11 /*y*/, 22 /*var*/);
 
            //System.NotSupportedException, this method is not marked with
            //OperationContractAttribute in both client and service sides. 
            trading.Foo99();
 
            Console.ReadLine();
        }
    }
}
 

Example Source Code

So, WCF is able to match in runtime service contract methods and its parameters numbers and names. It's a very useful capability for enterprise flexibility and amazing SOAP using structure for service versioning management (Service Versioning in my next post).

פורסם: Jul 14 2009, 02:02 AM by FanMix | with no comments