VB实现窗体透明与半透明效果源代码

半透明窗体(窗体对鼠标点击有反应): 
Option Explicit 

'Transparancy API's 
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 UpdateLayeredWindow Lib "user32" (ByVal hWnd As Long, ByVal hdcDst As Long, pptDst As Any, psize As Any, ByVal hdcSrc As Long, pptSrc As Any, crKey As Long, ByVal pblend As Long, 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 GWL_EXSTYLE = (-20) 
Private Const LWA_COLORKEY = &H1 
Private Const LWA_ALPHA = &H2 
Private Const ULW_COLORKEY = &H1 
Private Const ULW_ALPHA = &H2 
Private Const ULW_OPAQUE = &H4 
Private Const WS_EX_LAYERED = &H80000 


Public Function isTransparent(ByVal hWnd As Long) As Boolean 
On Error Resume Next 
Dim Msg As Long 
Msg = GetWindowLong(hWnd, GWL_EXSTYLE) 
If (Msg And WS_EX_LAYERED) = WS_EX_LAYERED Then 
isTransparent = True 
Else 
isTransparent = False 
End If 
If Err Then 
isTransparent = False 
End If 

End Function 

Public Function MakeTransparent(ByVal hWnd As Long, ByVal Perc As Integer) As Long 
Dim Msg As Long 
On Error Resume Next 

Perc = 100 
If Perc < 0 Or Perc > 255 Then 
MakeTransparent = 1 
Else 
Msg = GetWindowLong(hWnd, GWL_EXSTYLE) 
Msg = Msg Or WS_EX_LAYERED 
SetWindowLong hWnd, GWL_EXSTYLE, Msg 
SetLayeredWindowAttributes hWnd, 0, Perc, LWA_ALPHA 
MakeTransparent = 0 
End If 
If Err Then 
MakeTransparent = 2 
End If 
End Function 

Public Function MakeOpaque(ByVal hWnd As Long) As Long 
Dim Msg As Long 
On Error Resume Next 
Msg = GetWindowLong(hWnd, GWL_EXSTYLE) 
Msg = Msg And Not WS_EX_LAYERED 
SetWindowLong hWnd, GWL_EXSTYLE, Msg 
SetLayeredWindowAttributes hWnd, 0, 0, LWA_ALPHA 
MakeOpaque = 0 
If Err Then