UrlAttribute Class

Defines an attribute that can be used at the call site to specify the URL where the activation will happen. This class cannot be inherited.

System.Object
  System.Attribute
    System.Runtime.Remoting.Contexts.ContextAttribute
      System.Runtime.Remoting.Activation.UrlAttribute

Namespace:  System.Runtime.Remoting.Activation
Assembly:  mscorlib (in mscorlib.dll)

[SerializableAttribute]
[ComVisibleAttribute(true)]
public sealed class UrlAttribute : ContextAttribute

The UrlAttribute type exposes the following members.

  NameDescription
Public methodUrlAttributeCreates a new instance of the UrlAttribute class.
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  NameDescription
Public propertyNameInfrastructure. Gets the name of the context attribute. (Inherited from ContextAttribute.)
Public propertyTypeIdWhen implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)
Public propertyUrlValueGets the URL value of the UrlAttribute.
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  NameDescription
Public methodEqualsChecks whether the specified object refers to the same URL as the current instance. (Overrides ContextAttribute.Equals(Object).)
Public methodFreezeInfrastructure. Called when the context is frozen. (Inherited from ContextAttribute.)
Public methodGetHashCodeReturns the hash value for the current UrlAttribute. (Overrides ContextAttribute.GetHashCode().)
Public methodGetPropertiesForNewContextForces the creation of the context and the server object inside the context at the specified URL. (Overrides ContextAttribute.GetPropertiesForNewContext(IConstructionCallMessage).)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodIsContextOKReturns a Boolean value that indicates whether the specified Context meets UrlAttribute's requirements. (Overrides ContextAttribute.IsContextOK(Context, IConstructionCallMessage).)
Public methodIsDefaultAttributeWhen overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute.)
Public methodIsNewContextOKInfrastructure. Returns a Boolean value indicating whether the context property is compatible with the new context. (Inherited from ContextAttribute.)
Public methodMatchWhen overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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  NameDescription
Explicit interface implemetationPrivate method_Attribute.GetIDsOfNamesMaps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.)
Explicit interface implemetationPrivate method_Attribute.GetTypeInfoRetrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.)
Explicit interface implemetationPrivate method_Attribute.GetTypeInfoCountRetrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.)
Explicit interface implemetationPrivate method_Attribute.InvokeProvides access to properties and methods exposed by an object. (Inherited from Attribute.)
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The UrlAttribute is passed in the activation attributes array as a parameter to Activator.CreateInstance when creating activated objects with the CreateInstance method.

For more information about using attributes, see Extending Metadata Using Attributes.

The following code example illustrates the use of the UrlAttribute in setting up client-activated remoting. The example contains three parts: a client, a server, and a remote object that is used by the client and server.

The following code example shows a client:

using System;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Activation;
using System.Runtime.Remoting.Channels;
using System.Runtime.Remoting.Channels.Tcp;
using System.Security.Permissions;

public class Client
{
[SecurityPermission(SecurityAction.Demand)]
    [STAThread]
    public static void Main()
    {
        // Report the initial status.
        Console.WriteLine("Starting client.");

        // Register the TCP channel.
        ChannelServices.RegisterChannel(new TcpChannel());

        // Create a url attribute object.
        UrlAttribute attribute = 
            new UrlAttribute("tcp://localhost:1234/RemoteApp");
        Console.WriteLine("UrlAttribute value: {0}", attribute.UrlValue);
        object[] activationAttributes = new object[] { attribute };

        // Register the client for the remote object.
        RemotingConfiguration.RegisterActivatedClientType(
            typeof(RemoteObject), 
            "tcp://localhost:1234/RemoteApp");

        // Activate the remote object.
        Console.WriteLine("Activating remote object.");
        RemoteObject obj = (RemoteObject) Activator.CreateInstance(
            typeof(RemoteObject), null, activationAttributes);

        // Invoke a method on the remote object.
        Console.WriteLine("Invoking Hello() on remote object.");
        obj.Hello();

        // Inform the user that the program is exiting.
        Console.WriteLine("The client is exiting.");
    }
}

The following code example shows a server for this client:

using System;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Channels;
using System.Runtime.Remoting.Channels.Tcp;

public class Server
{
    [STAThread]
    public static void Main()
    {
        // Report the status to the user.
        Console.WriteLine("Starting server.");

        // Register the TCP channel.
        ChannelServices.RegisterChannel(new TcpChannel(1234));

        // Set the application name.
        RemotingConfiguration.ApplicationName = "RemoteApp";

        // Register the object for remoting.
        RemotingConfiguration.RegisterActivatedServiceType(
            typeof(RemoteObject));

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

The following code example shows the remote object that is used by the client and the server:

using System;
using System.Security;
using System.Security.Permissions;

public class RemoteObject : MarshalByRefObject
{
    public RemoteObject()
    {
        Console.WriteLine("You have called the constructor.");
    }

    public void Hello()
    {
        Console.WriteLine("You have called Hello().");
    }
}

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

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