现在有不少软件都采用了透明的窗口作为界面，如何在你的程序中实现呢？我发现在Win2k中提供了这种支持，只要简单的几行代码就可实现。(本例子目前只适用于Win2k )
拿一个对话框为例：
第一步 定义功能
typedef BOOL (FAR PASCAL * FUNC1)(
HWND hwnd, // handle to the layered window
COLORREF crKey, // specifies the color key
BYTE bAlpha, // value for the blend function
DWORD dwFlags // action
);
第二步 实现代码
在OnInitDialog中加入下列代码
.....
HMODULE hModule = GetModuleHandle("user32.dll");
FUNC1 SetLayeredWindowAttributes;
SetLayeredWindowAttributes = (FUNC1) GetProcAddress (hModule, _T( "SetLayeredWindowAttributes" ) );
// 设置分层扩展标记
SetWindowLong(GetSafeHwnd(), GWL_EXSTYLE, GetWindowLong(GetSafeHwnd(), GWL_EXSTYLE) | 0x80000L);
// 70% alpha
SetLayeredWindowAttributes(GetSafeHwnd(), 0, (255 * 70) / 100, 0x2);
工作完成，怎么样，现在你可以运行你的程序来查看效果，即使背景变化也能立刻反映到你的窗口当中，这一点比金山词霸的效果要好。
看到下面这段文章的人有福了，这是新加入的：
第三步：如何除去透明选项？
// 除去分层扩展标记
SetWindowLong(GetSafeHwnd(),, GWL_EXSTYLE,
GetWindowLong(GetSafeHwnd(), GWL_EXSTYLE) & ~ 0x80000L);
// 重画窗口
RedrawWindow();
第四部：VB的透明窗口(摘自MSDN)
Private Declare Function GetWindowLong Lib "user32" Alias _
"GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
Private Declare Function SetWindowLong Lib "user32" Alias _
"SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, _
ByVal dwNewLong As Long) As Long
Private Declare Function SetLayeredWindowAttributes Lib "user32" _
(ByVal hwnd As Long, ByVal crey As Byte, ByVal bAlpha As Byte, _
ByVal dwFlags As Long) As Long
Private Const GWL_EXSTYLE = (-20)
Private Const WS_EX_LAYERED = &H80000
Private Const WS_EX_TRANSPARENT = &H20&
Private Const LWA_ALPHA = &H2&
Option Explicit
Private Sub Form_Load()
Dim lOldStyle As Long
Dim bTrans As Byte ' The level of transparency (0 - 255)
bTrans = 128
lOldStyle = GetWindowLong(Me.hWnd, GWL_EXSTYLE)
SetWindowLong Me.hWnd, GWL_EXSTYLE, lOldStyle Or WS_EX_LAYERED
SetLayeredWindowAttributes Me.hWnd, 0, bTrans, LWA_ALPHA
End Sub
总算完整了一点。多谢观看。