Visual C++ and MFC Programming 2nd Edition

Visual C++ and MFC Fundamentals Chapter 5: The Document/View Architecture

WM_SHOWWINDOW: After creating a window, it needs to be displayed. Also, if the

window was previously hidden, you can decide to show it. On the other hand, if a

window is displaying, you may want to hide it, for any reason you judge necessary. To

take any of these actions, that is, to show or hide a window, you must send the

ON_WM_SHOWWINDOW message. The syntax of this message is:

afx_msg void OnShowWindow(BOOL bShow, UINT nStatus);

When using this message, bShow is a Boolean argument determines what state to apply to

the window. If it is TRUE, the window needs to be displayed. If it is FALSE, the

window must be hidden.

nStatus is a positive integer that can have one of the following values:

Value Description

SW_PARENTCLOSING

If the window that sent this message is a frame, the

window is being minimized.

If the window that sent this message is hosted by another

window, the window is being hidden.

SW_PARENTOPENING

If the window that sent this message is a frame, the

window is being restored.

If the window that sent this message is hosted by another

window, the window is displaying

0 The message was sent from a CWnd::ShowWindow()

method

Practical Learning: Showing a Window

1. To maximize the window at startup, change the program as follows:

#include <afxwin.h>

class CMainFrame : public CFrameWnd

{

public:

CMainFrame ();

protected:

afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);

afx_msg void OnShowWindow(BOOL bShow, UINT nStatus);

DECLARE_MESSAGE_MAP()

};

CMainFrame::CMainFrame()

{

// Create the window's frame

Create(NULL, "Windows Application", WS_OVERLAPPEDWINDOW,

CRect(120, 100, 700, 480), NULL);

}

class CExerciseApp: public CWinApp

{

public:

BOOL InitInstance();

};

BEGIN_MESSAGE_MAP(CMainFrame, CFrameWnd)