by Kalani COM (1 Submission)
Category: Custom Controls/Forms/Menus
Compatability: Visual Basic 3.0
Difficulty: Unknown Difficulty
Date Added: Wed 3rd February 2021
Rating: 
(104 Votes)
Makes a Form Trans Parent
Side Effects
No Controls are Visible on the Form
API DeclarationsDeclare Function GetWindowRect Lib "user32" (ByVal hWnd As Long, lpRECT As RECT) As Long
Declare Function GetClientRect Lib "user32" (ByVal hWnd As Long, lpRECT As RECT) As Long
Declare Function CombineRgn Lib "gdi32" (ByVal hDestRgn As Long, ByVal hSrcRgn1 As Long, ByVal hSrcRgn2 As Long, ByVal nCombineMode As Long) As Long
Declare Function CreateRectRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Declare Function ScreenToClient Lib "user32" (ByVal hWnd As Long, lpPoint As POINTAPI) As Long
Declare Function SetWindowRgn Lib "user32" (ByVal hWnd As Long, ByVal hRgn As Long, ByVal bRedraw As Boolean) As Long
Public Const RGN_AND = 1
Public Const RGN_COPY = 5
Public Const RGN_DIFF = 4
Public Const RGN_OR = 2
Public Const RGN_XOR = 3
Type POINTAPI
x As Long
Y As Long
End Type
Type RECT
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type
VBcodersPublic Sub MakeTransparent(frm As Form)
'This code was takin from a AOL Visual Basic
'Message Board. It was submited by: SOOPRcow
Dim rctClient As RECT, rctFrame As RECT
Dim hClient As Long, hFrame As Long
'// Grab client area and frame area
GetWindowRect frm.hWnd, rctFrame
GetClientRect frm.hWnd, rctClient
'// Convert client coordinates to screen coordinates
Dim lpTL As POINTAPI, lpBR As POINTAPI
lpTL.x = rctFrame.Left
lpTL.Y = rctFrame.Top
lpBR.x = rctFrame.Right
lpBR.Y = rctFrame.Bottom
ScreenToClient frm.hWnd, lpTL
ScreenToClient frm.hWnd, lpBR
rctFrame.Left = lpTL.x
rctFrame.Top = lpTL.Y
rctFrame.Right = lpBR.x
rctFrame.Bottom = lpBR.Y
rctClient.Left = Abs(rctFrame.Left)
rctClient.Top = Abs(rctFrame.Top)
rctClient.Right = rctClient.Right + Abs(rctFrame.Left)
rctClient.Bottom = rctClient.Bottom + Abs(rctFrame.Top)
rctFrame.Right = rctFrame.Right + Abs(rctFrame.Left)
rctFrame.Bottom = rctFrame.Bottom + Abs(rctFrame.Top)
rctFrame.Top = 0
rctFrame.Left = 0
'// Convert RECT structures to region handles
hClient = CreateRectRgn(rctClient.Left, rctClient.Top, rctClient.Right, rctClient.Bottom)
hFrame = CreateRectRgn(rctFrame.Left, rctFrame.Top, rctFrame.Right, rctFrame.Bottom)
'// Create the new "Transparent" region
CombineRgn hFrame, hClient, hFrame, RGN_XOR
'// Now lock the window's area to this created region
SetWindowRgn frm.hWnd, hFrame, True
End Sub