Visual C++ and MFC Programming 2nd Edition

Visual C++ and MFC Fundamentals Chapter 12: Dialog-Based Windows

int cy;

int cx;

int y;

int x;

LONG style;

LPCSTR lpszName;

LPCSTR lpszClass;

DWORD dwExStyle;

} CREATESTRUCT;

As you can see, the member variables of this structure are very similar to the arguments

of the Win32's CreateWindow() and CreateWindowEx() functions. Its member variables

correspond as follows:

CREATESTRUCT

CreateWindow

and

CreateWindowEx

Meaning

x x Distance from left border of monitor to left border of

window frame

Y y Distance from top border of monitor to top border of

window frame

cx nWidth

Distance from left border of monitor to right border of

window frame

cy nHeight

Distance from top border of monitor to bottom border of

window frame

Therefore, in your CFrameWnd::PreCreateWindow() event, assign the desired values

for the location and size of the window. In the following example, the original

dimensions of the window are set to 450x325 (width x height):

BOOL CMainFrame::PreCreateWindow(CREATESTRUCT& cs)

{

if( !CFrameWnd::PreCreateWindow(cs) )

return FALSE;

// TODO: Modify the Window class or styles here by modifying

// the CREATESTRUCT cs

cs.cx = 450;

cs.cy = 325;

return TRUE;

}

Of course, you can also use the PreCreateWindow() event to customize the appearance

of the window frame.

Once a regular window, that is, an overlapped window, has been created, it displays a

title bar, its system buttons, and borders. As stated already, if you created an application

using AppWizard, the window may appear in a random location, which you can control.

If you want the window to be positioned in the center of the screen, call the

CWnd::CenterWindow() method. Its syntax is:

void CenterWindow(CWnd* pAlternateOwner = NULL);

By default, this window positioned the caller (the window that called it) in the middle-

center of the main window, also called its owner. For a main frame of a window, the

owner would be the monitor screen. As long as the window is owned by another, the