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HttpClientChannel Class

Implements a client channel for remote calls that uses the HTTP protocol to transmit messages.

Namespace: System.Runtime.Remoting.Channels.Http
Assembly: System.Runtime.Remoting (in system.runtime.remoting.dll)

public class HttpClientChannel : BaseChannelWithProperties, IChannelSender, IChannel, ISecurableChannel
public class HttpClientChannel extends BaseChannelWithProperties implements IChannelSender, IChannel, 
	ISecurableChannel
public class HttpClientChannel extends BaseChannelWithProperties implements IChannelSender, IChannel, 
	ISecurableChannel

Channels transport messages across remoting boundaries (for example, between computers or application domains). The HttpClientChannel class transports messages using the HTTP protocol.

Channels are used by the .NET Framework remoting infrastructure to transport remote calls. When a client makes a call to a remote object, the call is serialized into a message that is sent by a client channel and received by a server channel. It is then deserialized and processed. Any returned values are transmitted by the server channel and received by the client channel.

To perform additional processing of messages on the client-side, you can specify an implementation of the IClientChannelSinkProvider through which all messages processed by the HttpClientChannel are passed.

By default, the HttpServerChannel uses a SOAP formatter to serialize all messages.

A HttpClientChannel object has associated configuration properties that can be set at run time either in a configuration file (by invoking the static RemotingConfiguration.Configure method) or programmatically (by passing a IDictionary collection to the HttpClientChannel constructor). For a list of these configuration properties, see Channel and Formatter Configuration Properties.

The following code example shows how to use a HttpClientChannel to set up a remoting server and its client. The example contains three parts:

  • A server

  • A client

  • A remote object used by the server and the client

The following code example shows a server.

using System;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Channels;
using System.Runtime.Remoting.Channels.Http;

public class Server
{
    public static void Main(string[] args)
    {
        // Create the server channel.
        HttpServerChannel serverChannel = new HttpServerChannel(9090);

        // Register the server channel.
        ChannelServices.RegisterChannel(serverChannel);

        // Expose an object for remote calls.
        RemotingConfiguration.RegisterWellKnownServiceType(
            typeof(RemoteObject), "RemoteObject.rem", 
            WellKnownObjectMode.Singleton);

        // Wait for the user prompt.
        Console.WriteLine("Press ENTER to exit the server.");
        Console.ReadLine();
        Console.WriteLine("The server is exiting.");
    }
}

The following code example shows a client for this server.

using System;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Channels;
using System.Runtime.Remoting.Channels.Http;
using System.Security.Permissions;

public class Client
{
[SecurityPermission(SecurityAction.Demand)]
    public static void Main(string[] args)
    {
        // Create the channel.
        HttpClientChannel clientChannel = new HttpClientChannel();

        // Register the channel.
        ChannelServices.RegisterChannel(clientChannel);

        // Register as client for remote object.
        WellKnownClientTypeEntry remoteType = 
            new WellKnownClientTypeEntry(typeof(RemoteObject), 
            "http://localhost:9090/RemoteObject.rem");
        RemotingConfiguration.RegisterWellKnownClientType(remoteType);

        // Create a message sink.
        string objectUri;
        System.Runtime.Remoting.Messaging.IMessageSink messageSink = 
            clientChannel.CreateMessageSink(
            "http://localhost:9090/RemoteObject.rem", 
            null, out objectUri);
        Console.WriteLine(
            "The URI of the message sink is {0}.", 
            objectUri);
        if (messageSink != null)
        {
            Console.WriteLine("The type of the message sink is {0}.", 
                messageSink.GetType().ToString());
        }

        // Display the channel's properties using Keys and Item.
        foreach(string key in clientChannel.Keys)
        {
            Console.WriteLine(
                "clientChannel[{0}] = <{1}>", 
                key, clientChannel[key]);
        }

        // Parse the channel's URI.
        string objectUrl = "http://localhost:9090/RemoteObject.rem";
        string channelUri = clientChannel.Parse(objectUrl, out objectUri);
        Console.WriteLine("The object URL is {0}.", objectUrl);
        Console.WriteLine("The object URI is {0}.", objectUri);
        Console.WriteLine("The channel URI is {0}.", channelUri);

        // Create an instance of the remote object.
        RemoteObject service = new RemoteObject(); 

        // Invoke a method on the remote object.
        Console.WriteLine("The client is invoking the remote object.");
        Console.WriteLine("The remote object has been called {0} times.", 
            service.GetCount());
    }
}

The following code example shows the remote object used by the server and the client.

using System;
using System.Runtime.Remoting;

// Remote object.
public class RemoteObject : MarshalByRefObject
{
    private int callCount = 0;

    public int GetCount()
    {
        Console.WriteLine("GetCount was called.");
        callCount++;
        return(callCount);
    }

}

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0
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