Teach Yourself Borland C++ in 14 Days - portal

132 Day 5
Frameworks 101
“In the beginning there was C….” If you recall, I started my discussion of the C++
programming language with that statement. The same is true of Windows programming—
in the beginning, the vast majority of Windows programs were written in C. In fact, the
Windows Application Programming Interface (API) is just a huge collection of C functions—hundreds
of them. There are still undoubtedly thousands of programmers out there
writing Windows programs in C.
Somewhere along the line, some folks at Borland decided, “There has got to be an easier way!”
(Actually, the framework revolution may have started on several different fronts at once, but
Borland was certainly a leader in the field.) It was apparent that Windows programming was
very well suited to the C++ language, and vice versa. By creating classes that encapsulate
common Windows programming tasks, a programmer could be much more productive.
Once a class was created to encapsulate the various duties of a window, for instance, that class
could be used over and over again. The framework revolution began.
But I haven’t actually told you what a framework is yet.
A framework is a collection of classes that simplifies programming in Windows by
encapsulating often-used programming techniques. Frameworks are also called class
libraries.
Popular frameworks have classes that encapsulate windows, edit controls, list boxes, graphics
operations, bitmaps, scrollbars, dialog boxes, and on and on.
NEW TERM
So What’s the Big Deal?
That’s a good question. The bottom line is that frameworks make Windows programming
much easier than it would be in straight C. Let me give you an example. Listing 5.1 contains
a portion of a Windows program written in C. This section of code loads a bitmap file from
disk and displays the bitmap in the center of the screen. None of this will make sense to you
right now, but that’s not the point.
Listing 5.1. C code to load and display a bitmap.
1: HPALETTE hPal;
2: BITMAPFILEHEADER bfh;
3: BITMAPINFOHEADER bih;
4: LPBITMAPINFO lpbi = 0;
5: HFILE hFile;
6: DWORD nClrUsed, nSize;
7: HDC hDC;