COM+ Unleashed

Chapter 6. Connectable Objects

In This Chapter

• Connection Points

• Connection Point Container

• Connection Point Example

• Events and Visual Basic

• How Different Tools Implement Events

This chapter shows you how to create and use events in Visual C++ and Visual Basic. COM+ does not inherently support the event model or callback functions. In many object models, classes can have three types of members: properties, methods, and events. Visual Basic and Delphi are object-oriented tools that provide these types of models.

COM+ provides direct support for COM+ classes having both properties and methods, but no COM+ structure is the equivalent of an event. This makes implementing COM+ events very difficult.

The model suggested by ActiveX is to provide a connection ...