PDA

Click to See Complete Forum and Search --> : Modify CheckBoxes/Radio buttons to show their background


Dec 26th, 2000, 06:53 AM
I found this code which allows you to make CheckBoxes & Opton Buttons Show their backgounds, like Label Controls with their Background set to Transparent.

-----------------------------------------------------------

CREATE SEE-THROUGH CONTROLS
Most standard controls send WM_CTLCOLORXXXXX messages to their parent when they’re about to draw themselves. VB normally handles these messages and responds appropriately with the ForeColor and BackColor properties that you have set for the control. However, it’s possible to override the standard behavior and achieve a transparent background with several basic control types. This example uses the ubiquitous MsgHook for subclassing, but you can use whichever method you prefer. You must ensure that ClipControls is set to False for the form; otherwise, you’ll see whatever is below your form as the background for the controls instead of the background bitmap:

Option Explicit

Private Declare Function SetBkMode Lib "gdi32" (ByVal hdc As Long, ByVal nBkMode As Long) As Long
Private Declare Function SetTextColor Lib "gdi32" (ByVal hdc As Long, ByVal crColor As Long) As Long
Private Declare Function GetStockObject Lib "gdi32" (ByVal nIndex As Long) As Long

Private Const WM_CTLCOLORSTATIC = &H138
Private Const TRANSPARENT = 1
Private Const NULL_BRUSH = 5

Private Sub Form_Load()
' Me.ClipControls = False
' Must be set at design-time!
Msghook1.HwndHook = Me.hWnd
Msghook1.Message(WM_CTLCOLORSTATIC) = True
End Sub

Private Sub Msghook1_Message(ByVal msg As Long, ByVal wp As Long, ByVal lp As Long, result As Long)
Select Case msg
Case WM_CTLCOLORSTATIC
' Call the original windowproc to handle the
' foreground colour for the Controls etc
Call Msghook1.InvokeWindowProc(msg, wp, lp)

' Set the background mode to transparent
Call SetBkMode(wp, TRANSPARENT)

' Get the stock null brush and return it
' The brush does nothing when the control
' paints using it, hence giving the
' transparency effect
result = GetStockObject(NULL_BRUSH)

Case Else
' [Replace this line with your own code
' to call the original windowproc]
result = Msghook1.InvokeWindowProc(msg, wp, lp)
End Select
End Sub
----------------------------------------------------------

I Cant get this to work using normal SubClassing without the Mabry MsgHook.ocx. Can somebody help.

What i want is to display the Picture Behind without any ugly patches. Thanks a lot.

Jop
Dec 26th, 2000, 04:52 PM
Hey Hartless!

This should do it!


In a module:
Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hwnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Public Const GWL_WNDPROC = (-4)

Private Declare Function SetBkMode Lib "gdi32" (ByVal hdc As Long, ByVal nBkMode As Long) As Long
Private Declare Function SetTextColor Lib "gdi32" (ByVal hdc As Long, ByVal crColor As Long) As Long
Private Declare Function GetStockObject Lib "gdi32" (ByVal nIndex As Long) As Long

Private Const WM_CTLCOLORSTATIC = &H138
Private Const TRANSPARENT = 1
Private Const NULL_BRUSH = 5


Dim Proc As Long

Public Sub SubClass(hWnd As Long)
Proc = SetWindowLong(hWnd, GWL_WNDPROC, AddressOf WindowProc)
End Sub

Public Sub unSubClass(hWnd As Long)
SetWindowLong hWnd, GWL_WNDPROC, Proc
End Sub

Public Function WindowProc(ByVal hwnd As Long, ByVal uMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
If uMsg = WM_CTLCOLORSTATIC then
' Call the original windowproc to handle the
' foreground colour for the Controls etc

WindowProc = CallWindowProc(Proc, hwnd, uMsg, wParam, lParam)

' Set the background mode to transparent
Call SetBkMode(wp, TRANSPARENT)

' Get the stock null brush and return it
' The brush does nothing when the control
' paints using it, hence giving the
' transparency effect
result = GetStockObject(NULL_BRUSH)
Else
WindowProc = CallWindowProc(Proc, hwnd, uMsg, wParam, lParam)
End if
End Function


in a form:

Private Sub Form_Load()
SubClass Me.hWnd
End Sub

Private Sub Form_Unload(Cancel As Integer)
unSubClass Me.hWnd
End Sub


Something like that, but that's main way of subclassing and intercepting the messages.
I their code to redraw the stuff in the WindowProc sub.

Have fun!

[Edited by Jop on 12-26-2000 at 05:56 PM]

Dec 27th, 2000, 12:57 PM
Thanks for your you prompt reply, but I'm afraid that doesn't work :(

I tried it using similar code but it doesn't work without the Mabry MsgHook Control.

Thanks anyways.

Jop
Dec 27th, 2000, 04:48 PM
hmm.. download & use it then :)

Jan 3rd, 2001, 01:25 AM
in the properties window
you can change the mode of the
object to a graphic mode
this should be working