MFC dialog box fade-in and fade-out

example 1 :

set up with function AnimateWindow() .

::this method can't set up one CDialog which is transparent

1. In the header file stdafx. H, add:

# UNDEF winver // undefines the original version and redefines the version

# Define winver 0x5000 // to make the animatewindow function available

2. Implementation functions:

Animatewindow (getsafehwnd (), 1000, aw_blend); // fade into the form for 1 second

Animatewindow (getsafehwnd (), 1000, aw_blend | aw_hide); // fades out the form for 1 second

/*

example 2 :

set up with function ::SetLayeredWindowAttributes() */

//SmoothDlgDlg.h

HMODULEm_hUserDll;

//SmoothDlgDlg.CPP

// This function sets the transparency of the form by calling the setlayeredwindowattributes API Function

BOOL CSmoothDlgDlg::SetTransparent(HWND hWnd, COLORREF crKey, BYTE bAlpha, DWORD dwFlags)

{

BOOL bRet = TRUE;

typedef BOOL (WINAPI* lpfnSetTransparent)(HWND hWnd, COLORREF crKey, BYTE bAlpha, DWORD dwFlags);

// Check whether the USER32 dynamic Connection Library has been loaded

if(m_hUserDll)

{

 lpfnSetTransparentpFnSetTransparent = NULL;

 pFnSetTransparent=(lpfnSetTransparent)GetProcAddress(m_hUserDll,"SetLayeredWindowAttributes");

 if(pFnSetTransparent)

  bRet = pFnSetTransparent(hWnd, crKey, bAlpha, dwFlags);

 else

  bRet = FALSE;

}

returnbRet;

}

voidCSmoothDlgDlg::OnClose()

{

// Cyclically increase the transparency of the window

for(int nPercent = 100; nPercent >= 0 ; nPercent --)

 SetTransparent(m_hWnd, 0, 255 * nPercent / 100, LWA_ALPHA);

// Release USER32 dynamic Connection Library

if(m_hUserDll)

 ::FreeLibrary(m_hUserDll);

CDialog::OnClose();}

Add the following code to the window initialization function:

BOOLCSmoothDlgDlg::OnInitDialog()

{

CDialog::OnInitDialog();

// Load the USER32 dynamic Connection Library

m_hUserDll=::LoadLibrary(_T("USER32.dll"));

// Set the window style to ws_ex_layered (stacked window style)

::SetWindowLong(m_hWnd, GWL_EXSTYLE, ::GetWindowLong(m_hWnd,GWL_EXSTYLE) | WS_EX_LAYERED);

SetTransparent(m_hWnd, 0, 255 * 100 / 100, LWA_ALPHA);

// Some automatically generated codes are omitted here

return TRUE;//return TRUE unless you set the focus to acontrol

}