Visual Basic 2005 Delegates

Delegates are type-safe reference types that provide similar functions to pointers in other languages. PowerDesigner models delegates as classes with a stereotype of <<Delegate>> with a single operation code-named "<signature>". The visibility, name, comment, flags and attributes are specified on the class object whereas the return-type and parameters are specified on the operation.

For information about creating and working with classes, see Classes (OOM).

You can design the following types of VB .NET delegates:

To create a delegate at the namespace level, create a class with the <<Delegate>> stereotype, and add an operation with the <<Delegate>> stereotype to this class and define a visibility for this operation. This visibility becomes the visibility of the delegate
... Public Delegate Function ActionOccurred () As Object ...
To create a delegate in a class, module, or structure, you just have to create an operation with the <<Delegate>> stereotype. In the following example, class Worker is inner to module Utilities. Both contain internal delegates designed as operations with the <<Delegate>> stereotype
... Public Module Utilities Public Delegate Function NewWorker () As Object Public Class Worker Public Delegate Function WorkStarted () As Object End Class End Module ...

Creating a Delegate

You can create a delegate in any of the following ways:

Use the Delegate tool in the Visual Basic 2005 Toolbox.
Select Model > Delegate Objects to access the List of Delegate Objects, and click the Add a Row tool.
Right-click the model (or a package) in the Browser, and select New > Delegate.

Delegate Properties

Visual Basic 2005 delegate property sheets contain all the standard delegate tabs along with the following properties, located on the VB tab:

Property	Description
Explicit	Specifies the Explicit option directive for the delegate declaration.
Shadows	Specifies that the delegate redefines a delegate defined in a parent delegate.
Strict	Specifies the Strict option directive for the delegate declaration.
Compare	Specifies the Compare option directive for the delegate declaration.