WebReference.com - Part 1 of Chapter 6: Professional C# Web Services, from Wrox Press Ltd (5/8)

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Professional C# Web Services

Client

Creating the client is as simple as creating the server. Here we will create a client using a configuration file.

Client Configuration File

The client configuration file SimpleClient.exe.config uses the XML <client> element to specify the URL of the server using protocol://hostname:port/application. In this example we use tcp as the protocol, and the server runs on localhost with the port number 9000. The application name of the server is defined with the name attribute of the <application> element in the server configuration file.

The <wellknown> element specifies the remote object we want to access. As in the server configuration file, the type attribute defines the type of the remote object and the assembly. The url attribute defines the path to the remote object. Appended to the URL of the application is the endpoint name MyRemoteObject. The channel that is configured with the client can again be found in the configuration file machine.config, but this time it is the client channel:

<configuration>
   <system.runtime.remoting>
      <application name="SimpleClient">
         <client url="tcp://localhost:9000/SimpleServer">
            <wellknown 
               type="Wrox.Samples.MyRemoteObject, MyRemoteObject"
               url = 
               "tcp://localhost:9000/SimpleServer/MyRemoteObject" 
             />
         </client>
         <channels>
            <channel ref="tcp client" />
         </channels>
      </application>
   </system.runtime.remoting>
</configuration>

Client Application

As in the server, we can activate the client channel by calling RemotingConfiguration.Configure(). Using configuration files we can simply use new to create the remote object. Next we call the method Hello() of this object:

// SimpleClient.cs
using System;
using System.Runtime.Remoting;
namespace Wrox.Samples
{
   class SimpleClient
   {
      static void Main(string[] args)
      {
         RemotingConfiguration.Configure("SimpleClient.exe.config");
         MyRemoteObject obj = new MyRemoteObject(); 
         Console.WriteLine(obj.Hello());
     }
   }
}

We can compile the client to a console application as we've done before with the server:

csc /target:exe /reference:MyRemoteObject.dll SimpleClient.cs

The assembly of the remote object must also be copied for the client application as well, but here it is clearer as we have to reference it explicitly in the compiler command.

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Created: February 13, 2002
Revised: February 13, 2002

URL: http://webreference.com/programming/csharp/webservices/chap6/1/5.html