ExternalDataExchangeAttribute Class
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ExternalDataExchangeAttribute Class

Note: This API is now obsolete.

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)]
[ObsoleteAttribute("The System.Workflow.* types are deprecated.  Instead, please use the new types from System.Activities.*")]
public sealed class ExternalDataExchangeAttribute : Attribute


Initializes a new instance of the ExternalDataExchangeAttribute.


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


This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)


Returns the hash code for this instance.(Inherited from Attribute.)


Gets the Type of the current instance.(Inherited from Object.)


When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)


When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)


Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)


Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.(Inherited from Attribute.)


This material discusses types and namespaces that are obsolete. For more information, see Deprecated Types in Windows Workflow Foundation 4.5.

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, see.7b1708da-fd2a-47da-902b-3d50580ee781

public interface IStartPurchaseOrder
    event EventHandler<InitiatePOEventArgs> InitiatePurchaseOrder;

.NET Framework
Available since 3.0

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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