SetLayeredWindowAttributes未定义的解决方案

1 对于未定义的风格进行自定义

#define WS_EX_LAYERED 0x00080000
#define LWA_COLORKEY 0x00000001

2 动态链接函数

typedef
BOOL
(WINAPI *PFN_SETLAYEREDWINDOWATTRIBUTES)(
           HWND hwnd,
           COLORREF crKey,
           BYTE bAlpha,
           DWORD dwFlags);

PFN_SETLAYEREDWINDOWATTRIBUTES SetLayeredWindowAttributes = NULL;

HMODULE m_hUser32 = LoadLibrary(_T("User32.dll"));
 SetLayeredWindowAttributes = (PFN_SETLAYEREDWINDOWATTRIBUTES)GetProcAddress(m_hUser32, "SetLayeredWindowAttributes");

如果想通过SetLayeredWindowAttributes函数来设置窗口的透明度，那么还要求窗口具有WS_EX_LAYERED的属性

// 设置分层扩展标记
 #define WS_EX_LAYERED 0x00080000
 SetWindowLong( m_hWnd, GWL_EXSTYLE, GetWindowLong(GetSafeHwnd(), GWL_EXSTYLE) | WS_EX_LAYERED);

然后就可以设置窗口的透明度了！