Chapter 11. The Windows API

Chapter 11. The Windows API

The Windows API has a bad rap among many Access programmers
who think it's too hard to figure out, too hard to call, or just plain
mysterious. We're here to prove that none of these is the case梕ven if you've
never seen the Windows API programmer's reference, you can use the Windows API,
given some help. In this chapter, we'll present some interesting uses of the
Windows API from within Access, with example forms and modules for each
solution. In most cases, using these in your own applications entails little
more than simply importing a module or two and then calling the functions. We've
divided the solutions in this chapter into three broad categories, as follows:

The Windows user interface

You'll learn how to remove a form's system menu, how to
maximize and minimize buttons at runtime, and how to draw attention to a
specific form by flashing its titlebar or icon. We'll discuss
language-independent classification of keypresses, so you can monitor exactly
what keys have been pressed. We'll also show how to restrict mouse movement to
a specific area on the screen.

The Windows shell

You'll learn how to have asynchronous code run another
program and pause until the other program is done before continuing. We'll
demonstrate a method for shutting down Windows under program control and show
you all the options of the associated API functions. You'll learn to find and
run an application, given an associated data file, and how to determine if the
application is already running. You'll see how to retrieve a list of all open
top-level windows (generally, one per application) and how to close a window
from your VBA code.

Files, drives, and hardware

You'll learn how to set file date and time stamp
information, which is useful if you're moving files around from within
applications or making backups based on dates. You'll also learn how to
retrieve information about your disk drives, hardware, and the current Windows
environment as well as how to connect and disconnect from remote network
devices programmatically or using standard dialogs.

 

Most of the solutions in this chapter instruct you to import one or more modules from the example databases. In each case, the module contains the Windows API user-defined types and function declarations you need for the example. If you've already imported a module with the specified name for a previous solution, you can skip it, since all modules with matching names contain the same code.