void CFloatWnd::OnUpdateTransparent(int iTransparent)
{
HINSTANCE hInst = LoadLibrary("User32.DLL");
if(hInst)
{
typedef BOOL (WINAPI *SLWA)(HWND,COLORREF,BYTE,DWORD);
SLWA pFun = NULL;
//取得SetLayeredWindowAttributes函数指针 
pFun = (SLWA)GetProcAddress(hInst,"SetLayeredWindowAttributes");
if(pFun)
{
pFun(m_hWnd,0,iTransparent,2);
}
FreeLibrary(hInst); 
}
}