Visual Basic Tutorials

Creating
ActiveX Controls

A wide assortment of development tools—including Microsoft Visual C++, Microsoft Visual J++, Microsoft Visual Basic, Microsoft Visual FoxPro, Borland Delphi, PowerBuilder, and Microsoft Access—support ActiveX controls. Until recently, however, the only tool available for creating ActiveX controls was Visual C++. This relegated development of ActiveX controls to the province of those who knew lower-level programming languages such as C and C++. With Visual Basic, Microsoft has given developers another tool for creating ActiveX controls. Using Visual Basic, you can create controls for your own software projects or for distribution and sale to other developers for use in their software. In fact, a developer writing applications in C++ and Java can use the ActiveX controls you create in Visual Basic.

ActiveX controls that you build in Visual Basic (or any language, for that matter) are not only useful in development tools but also in end-user applications. For example, you can embed an ActiveX control created in Visual Basic in an HTML document that will be viewed in a Web browser such as Microsoft Internet Explorer. The application in which an ActiveX control is displayed is referred to as the control’s container. Visual Basic is the ActiveX control container used for most of the examples in this chapter—however, keep in mind that your control might be activated in containers other than Visual Basic.