In the early 1990s, it appeared that C++ was going to take the world by storm. This is because C++ permitted programmers to create classes that could be reused and extended by other programmers within the organization. In theory, this seemed like the silver bullet that corporate IS departments were looking for. To switch metaphors, this was the 'Holy Grail' of code reusability and the ability to not rewrite functionality from scratch for each project. However, in practice, things didn't quite work out this way. C++ classes are very abstract and difficult to use. And so programmers would change the classes for each project making reuse more of a dream than a reality.
Visual Basic then came on the scene with 16-bit
controls - such as the text box. As the language evolved and we got to VB3.0, we saw the birth of a remarkable control that came bundled with the language - the data control. A huge third party cottage industry sprang up to develop these controls. Then with VB4.0, 32 bit .VBX
controls were introduced that were even more powerful. These generalized visual controls were pre-built, and came with tons of functionality. Programmers simply drew the pre-configured controls on a form and could then concentrate on writing the application..OCX
As such, these controls were a huge success. So much so, in fact, that the
controls actually accomplished what the C++ classes failed to produce - true code reusability. And these controls are attributed with making VB the most popular Windows programming language ever - with more than a million VB programmers worldwide..OCX
Just before we set about creating our custom ActiveX data control, let's take a minute to consider the important concept of data binding.