Creating an ActiveX document has great similarities to creating an ActiveX control. Just as with ActiveX controls, you are not necessarily in control of the host application — you are a cog in somebody else's machine. Therefore, much of your code must be defensive — allow your application to gracefully exit when necessary. And, as when developing an ActiveX control, you can expose methods, events and properties that can be used by other components.
The topics in this chapter provide the basic facts and concepts you need to create ActiveX documents. First, however, is a recap of the process of ActiveX document creation.
The process of creating an ActiveX document is like creating any other project in Visual Basic:
The .exe or .dll file contains the actual compiled code. Initially, the .vbd file contains the class ID of the .exe or the .dll file. If you elect to allow users to save data (using the PropertyBag), the data will also be stored in the .vbd file. Users can view your ActiveX document by opening the .vbd file in a host application.
For More Information Deployment of ActiveX documents is covered in "Building Internet Applications." For more information about the difference between the in-process and out-of-process components, see "In-Process and Out-of-Process ActiveX Documents." Details about the .vbd file are covered in "Parts of an ActiveX Document."