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ExternalDataExchangeAttribute Class

Marks an interface as a local service interface. This class cannot be inherited.


Namespace:  System.Workflow.Activities
Assembly:  System.Workflow.Activities (in System.Workflow.Activities.dll)

[AttributeUsageAttribute(AttributeTargets.Interface, AllowMultiple = false, 
	Inherited = false)]
public sealed class ExternalDataExchangeAttribute : Attribute

The ExternalDataExchangeAttribute type exposes the following members.

Public methodExternalDataExchangeAttributeInitializes a new instance of the ExternalDataExchangeAttribute.

Public propertyTypeIdWhen implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)

Public methodEqualsInfrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeReturns the hash code for this instance. (Inherited from Attribute.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
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 methodMatchWhen overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)

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.)

A class that implements a local service interface must be added to the ExternalDataExchangeService and can be used by CallExternalMethodActivity and HandleExternalEventActivity.

Events on interfaces that are attributed with ExternalDataExchangeAttribute should have event data that derive from ExternalDataEventArgs.

While generic types are supported for interface method and event declarations, generic types are not supported for the interface declaration itself. The following interface would not be valid for use as an ExternalDataExchange.

public interface IInterfaceName<TCommand>
    void MethodName(TCommand Request);

The following code example shows how to set the ExternalDataExchangeAttribute on an interface. This code example is part of the ActiveDirectoryRoles SDK sample from the IStartPurchaseOrder.cs file. For more information, seeUsing Active Directory Roles.

public interface IStartPurchaseOrder
    event EventHandler<InitiatePOEventArgs> InitiatePurchaseOrder;

.NET Framework

Supported in: 4, 3.5, 3.0

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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.