MFC 对话框淡入淡出效果

example 1 :

set up with function AnimateWindow() .

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

1.在头文件StdAfx.h中,添加: 

#undef WINVER //取消原有版本定义,重新定义版本 

#define WINVER 0x5000 //为了使AnimateWindow函数可用 

2.实现函数: 

AnimateWindow(GetSafeHwnd(), 1000, AW_BLEND); //淡入窗体1秒

AnimateWindow(GetSafeHwnd(), 1000, AW_BLEND | AW_HIDE); //淡出窗体1秒 

/*

example 2 :

set up with function ::SetLayeredWindowAttributes() */

//SmoothDlgDlg.h

HMODULEm_hUserDll;

//SmoothDlgDlg.CPP

//这个函数通过调用SetLayeredWindowAttributes API 函数来设定窗体的透明效果

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);

//检查User32动态连接库是否已经装入

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()

{

//循环增加窗口的透明度

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

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

//释放User32动态连接库

if(m_hUserDll)

 ::FreeLibrary(m_hUserDll);

CDialog::OnClose();}

另需在窗口初始化函数中添加如下代码：

BOOLCSmoothDlgDlg::OnInitDialog()

{

CDialog::OnInitDialog();

//装载User32动态连接库

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

//设置窗口样式为WS_EX_LAYERED（层叠窗口样式）

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

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

//......此处略去了自动生成的代码若干

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

}