HttpChannel Class

Definition

Namespace:

System.Runtime.Remoting.Channels.Http

Assembly:

System.Runtime.Remoting.dll

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

public ref class HttpChannel : System::Runtime::Remoting::Channels::BaseChannelWithProperties, System::Runtime::Remoting::Channels::IChannelReceiver, System::Runtime::Remoting::Channels::IChannelReceiverHook, System::Runtime::Remoting::Channels::IChannelSender, System::Runtime::Remoting::Channels::ISecurableChannel

public class HttpChannel : System.Runtime.Remoting.Channels.BaseChannelWithProperties, System.Runtime.Remoting.Channels.IChannelReceiver, System.Runtime.Remoting.Channels.IChannelReceiverHook, System.Runtime.Remoting.Channels.IChannelSender, System.Runtime.Remoting.Channels.ISecurableChannel

type HttpChannel = class
    inherit BaseChannelWithProperties
    interface IChannelReceiver
    interface IChannel
    interface IChannelSender
    interface IChannelReceiverHook
    interface ISecurableChannel

Public Class HttpChannel
Inherits BaseChannelWithProperties
Implements IChannelReceiver, IChannelReceiverHook, IChannelSender, ISecurableChannel

Inheritance

Object

BaseChannelObjectWithProperties

BaseChannelWithProperties

HttpChannel

Implements

IChannel IChannelReceiver IChannelReceiverHook IChannelSender ISecurableChannel

Examples

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.dll>
#using <System.Runtime.Remoting.dll>
#using "common.dll"
using namespace System;
using namespace System::Runtime::Remoting;
using namespace System::Runtime::Remoting::Channels;
using namespace System::Runtime::Remoting::Channels::Http;

void main()
{
   // Create the server channel.
   HttpServerChannel^ serverChannel = gcnew HttpServerChannel( 9090 );
   
   // Register the server channel.
   ChannelServices::RegisterChannel( serverChannel );
   
   // Expose an object for remote calls.
   RemotingConfiguration::RegisterWellKnownServiceType( RemoteObject::typeid, L"RemoteObject.rem", WellKnownObjectMode::Singleton );
   
   // Wait for the user prompt.
   Console::WriteLine( L"Press ENTER to exit the server." );
   Console::ReadLine();
   Console::WriteLine( L"The server is exiting." );
}

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.dll>
#using <System.Runtime.Remoting.dll>
#using "common.dll"

using namespace System;
using namespace System::Runtime::Remoting;
using namespace System::Runtime::Remoting::Channels;
using namespace System::Runtime::Remoting::Channels::Http;
void main()
{
   // Create the channel.
   HttpClientChannel^ clientChannel = gcnew HttpClientChannel;

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

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

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

   // Display the channel's properties using Keys and Item.
   for each(String^ key in clientChannel->Keys)
   {
       Console::WriteLine("clientChannel[{0}] = <{1}>", key, clientChannel[key]);
   }

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

   // Create an instance of the remote object.
   RemoteObject^ service = gcnew RemoteObject;
   
   // Invoke a method on the remote object.
   Console::WriteLine( L"The client is invoking the remote object." );
   Console::WriteLine( L"The remote object has been called {0} times.", service->GetCount() );
}

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

public class Client
{
    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.dll>
using namespace System;
using namespace System::Runtime::Remoting;

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

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

};

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);
    }
}

Remarks

Important

Calling methods from this class with untrusted data is a security risk. Call the methods from this class only with trusted data. For more information, see Validate All Inputs.

Channels transport messages across remoting boundaries (for example, between computers or application domains). The HttpChannel 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.

A HttpChannel 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 HttpChannel constructor). For a list of these configuration properties, see Channel and Formatter Configuration Properties.

Constructors

HttpChannel()	Initializes a new instance of the HttpChannel class.
HttpChannel(IDictionary, IClientChannelSinkProvider, IServerChannelSinkProvider)	Initializes a new instance of the HttpChannel class with the specified configuration properties and sinks.
HttpChannel(Int32)	Initializes a new instance of the HttpChannel class with a server channel that listens on the specified port.

Fields

SinksWithProperties

Indicates the top channel sink in the channel sink stack. (Inherited from BaseChannelWithProperties)

Properties

ChannelData	Gets the channel-specific data.
ChannelName	Gets the name of the current channel.
ChannelPriority	Gets the priority of the current channel.
ChannelScheme	Gets the type of listener to hook into (for example, "http").
ChannelSinkChain	Gets the channel sink chain that the current channel is using.
Count	Gets the number of properties associated with the channel object. (Inherited from BaseChannelObjectWithProperties)
IsFixedSize	Gets a value that indicates whether the number of properties that can be entered into the channel object is fixed. (Inherited from BaseChannelObjectWithProperties)
IsReadOnly	Gets a value that indicates whether the collection of properties in the channel object is read-only. (Inherited from BaseChannelObjectWithProperties)
IsSecured	Gets or sets a Boolean value that indicates whether the current channel is secure.
IsSynchronized	Gets a value that indicates whether the dictionary of channel object properties is synchronized. (Inherited from BaseChannelObjectWithProperties)
Item[Object]	Returns the specified channel property.
Keys	Gets a ICollection of keys that the channel properties are associated with.
Properties	Gets a IDictionary of the channel properties associated with the current channel.
SyncRoot	Gets an object that is used to synchronize access to the BaseChannelObjectWithProperties. (Inherited from BaseChannelObjectWithProperties)
Values	Gets a ICollection of the values of the properties associated with the channel object. (Inherited from BaseChannelObjectWithProperties)
WantsToListen	Gets a Boolean value that indicates whether the current instance wants to be hooked into the outside listener service.

Methods

Add(Object, Object)	Throws a NotSupportedException. (Inherited from BaseChannelObjectWithProperties)
AddHookChannelUri(String)	Adds a URI on which the channel hook should listen.
Clear()	Throws a NotSupportedException. (Inherited from BaseChannelObjectWithProperties)
Contains(Object)	Returns a value that indicates whether the channel object contains a property that is associated with the specified key. (Inherited from BaseChannelObjectWithProperties)
CopyTo(Array, Int32)	Throws a NotSupportedException. (Inherited from BaseChannelObjectWithProperties)
CreateMessageSink(String, Object, String)	Returns a channel message sink that delivers messages to the specified URL or channel data object.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetEnumerator()	Returns a IDictionaryEnumerator that enumerates over all the properties associated with the channel object. (Inherited from BaseChannelObjectWithProperties)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
GetUrlsForUri(String)	Returns an array of all the URLs for an object with the specified URI, hosted on the current HttpChannel.
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
Parse(String, String)	Extracts the channel URI and the remote well-known object URI from the specified URL.
Remove(Object)	Throws a NotSupportedException. (Inherited from BaseChannelObjectWithProperties)
StartListening(Object)	Instructs the current channel to start listening for requests.
StopListening(Object)	Instructs the current channel to stop listening for requests.
ToString()	Returns a string that represents the current object. (Inherited from Object)

Explicit Interface Implementations

IEnumerable.GetEnumerator()

Returns a IEnumerator that enumerates over all the properties that are associated with the channel object. (Inherited from BaseChannelObjectWithProperties)

Extension Methods

Cast<TResult>(IEnumerable)	Casts the elements of an IEnumerable to the specified type.
OfType<TResult>(IEnumerable)	Filters the elements of an IEnumerable based on a specified type.
AsParallel(IEnumerable)	Enables parallelization of a query.
AsQueryable(IEnumerable)	Converts an IEnumerable to an IQueryable.

See also

• Channel and Formatter Configuration Properties