使用VB6的半透明窗体

Question

是否可以创建一个半透明的窗体，它应该在任何打开的窗口中可见，而不是隐藏在后面？请指导！

Answer 1

当然，看到卡尔·彼得森的“半透明”的例子：http://vb.mvps.org/samples/Translucent/

为了保持在其他窗口可见的形式，你想使用SetWindowPos API函数。

Private Declare Function SetWindowPos Lib "user32" (ByVal hWnd As Long, ByVal hWndInsertAfter As Long, ByVal x As Long, ByVal y As Long, ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long) As Long 

Private Const HWND_TOPMOST = -1 
Private Const SWP_NOMOVE = &H2 
Private Const SWP_NOSIZE = &H1 
Private Const OnTopFlags = SWP_NOMOVE Or SWP_NOSIZE 

Public Sub FormOnTop(frm As Form) 
    Call SetWindowPos(frm.hWnd, HWND_TOPMOST, 0&, 0&, 0&, 0&, OnTopFlags) 
End Sub 

Answer 2

'function to make transparent' 

Private Declare Function SetLayeredWindowAttributes Lib "user32" (ByVal hwnd As Long,ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long 

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 Const G = (-20) 
Private Const LWA_COLORKEY = &H1  'to trans' 
Private Const LWA_ALPHA = &H2   'to semi trans' 
Private Const WS_EX_LAYERED = &H80000 

Private Sub Form_Activate() 
    Me.BackColor = vbBlue 
    Trans 1 
End Sub 

Private Sub Trans(Level As Integer) 
    Dim Msg As Long 
    Msg = GetWindowLong(Me.hwnd, G) 
    Msg = Msg Or WS_EX_LAYERED 
    SetWindowLong Me.hwnd, G, Msg 
    SetLayeredWindowAttributes Me.hwnd, vbBlue, Level, LWA_COLORKEY 
End Sub