Private Const GWL_EXSTYLE As Long = (-20)
Private Const LWA_ALPHA As Long = &H2
Private Const WS_EX_LAYERED As Long = &H80000
Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As  Long
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 SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As  Long
        
Public Sub SetFormTransparence(ByVal lHwnd As Long, ByVal bTransparent As Boolean)
    Dim lStyle As Long
    lStyle = GetWindowLong(lHwnd, GWL_EXSTYLE)
    If lStyle <> (lStyle Or WS_EX_LAYERED) Then Call SetWindowLong(lHwnd,  GWL_EXSTYLE, lStyle Or WS_EX_LAYERED)
    
    Call SetLayeredWindowAttributes(lHwnd,  0&, IIf(bTransparent, 127, 255), LWA_ALPHA)
End Sub

Private Const GWL_EXSTYLE As Long = (-20)
Private Const LWA_ALPHA As Long = &H2
Private Const WS_EX_LAYERED As Long = &H80000
Private Declare Function FindWindowA Lib "user32" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As  Long
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 SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As  Long
Public Sub SetFormTransparence(ByVal sUserformCaption As String, ByVal bTransparent As Boolean)
    Dim lHwnd  As Long
    Dim lStyle As Long
    lHwnd = FindWindowA("Thunder" & IIf(Application.Version Like "8*", "X", "D") & "Frame", sUserformCaption)
    If lHwnd <> 0 Then
        lStyle = GetWindowLong(lHwnd, GWL_EXSTYLE)
        If lStyle <> (lStyle Or WS_EX_LAYERED) Then Call SetWindowLong(lHwnd,  GWL_EXSTYLE, lStyle Or WS_EX_LAYERED)
        
        Call SetLayeredWindowAttributes(lHwnd,  0&, IIf(bTransparent, 127, 255), LWA_ALPHA)
    End If
End Sub

Public Sub SetFormTransparence(ByRef frm As System.Windows.Forms.Form, ByVal bTransparent As Boolean)
    If bTransparent Then frm.Opacity = 0.5# Else frm.Opacity = 1.0#
End Sub

public void SetFormTransparence(System.Windows.Forms.Form frm, Boolean bTransparent)
{
    frm.Opacity = (bTransparent == true ? 0.5 : 1);
}