Visual Basic Subclassing Routines
WM_DRAWITEM: Set Command Button ForeColor
     
Posted:   Monday July 12, 1999
Updated:   Monday December 26, 2011
     
Applies to:   VB5, VB6
Developed with:   VB6, Windows NT4
OS restrictions:   None
Author:   Steve Derderian, VBnet - Randy Birch, Rui Trigueiros
     

Related:  

SetWindowLong: Changing Button Caption Alignment (non-graphical only)
Pure VB: Mimicking a Command Button ForeColor Property
WM_DRAWITEM: Set Command Button ForeColor
SendMessage: Visually Pressing a Command Button Through Code
     
 Prerequisites
VB5 or VB6. Please see the Comments section below for important info.

Perhaps because of the popularity of skins, or perhaps just to make an application appear unique, another popular newsgroup question is how to set the forecolor of a command button text. While the Graphical style provides the means to change the button's BackColor, the intrinsic button class used by all command buttons does not provide a means to set the button text to other than the system default specified by the user in Control Panel. This code example, based on an example provided to the msnews newsgroups by Steve Derderian, shows one way to achieve this effect.

This technique uses AddressOf and the drawing APIs to redraw the button's caption in the chosen colour overtop the normal black caption. The code correctly offsets the button text when the button is depressed, and allows any button - whether an individual control, just specific members of a control array, or the entire control array - to have a unique button colour assigned.

A VBnet tip-of-the-hat goes out to Rui Trigueiros who helped track down and fix a bug causing mis-drawing of the offset text under XP. Please see the comments below for a description, especially if you have used pre-July 2004 versions of this code in your applications.

 BAS Module Code
Paste the following code into the general declarations area of a bas module:

Option Explicit
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Copyright 1996-2011 VBnet/Randy Birch, All Rights Reserved.
' Some pages may also contain other copyrights by the author.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Distribution: You can freely use this code in your own
'               applications, but you may not reproduce 
'               or publish this code on any web site,
'               online service, or distribute as source 
'               on any media without express permission.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'***********************************************************************
'*                                                                     *
'*  Copyright 1999 by Steve Derderian - The National Software Company  *
'*                                                                     *
'*  Overview:                                                          *
'*                                                                     *
'*  This module allows you to colour the button text in a Visual Basic *
'*  application.  The module can only be used from VB program code     *
'*  (probably in the Form_Load event).                                 *
'*                                                                     *
'*  Button text will appear black in the development environment.  It  *
'*  will only be coloured while the program is running. All other      *
'*  button properties, methods and events will work normally.          *
'*                                                                     *
'*                                                                     *
'*  Only three steps are required to use this module.                  *
'*      1.  Include this module in your VB project.                    *
'*      2.  When you add a button to the form set the style property   *
'*          to Graphical.                                              *
'*      3.  Call "RegisterButton" for each button you want to colour.  *
'*                                                                     *
'*                                                                     *
'*                                                                     *
'*                                                                     *
'*  RegisterButton:                                                    *
'*                                                                     *
'*  Used to start colouring a button's text.                           *
'*                                                                     *
'*  Syntax -- RegisterButton(<Button>, <Forecolor>)                    *
'*                                                                     *
'*  Part               Description                                     *
'*  ------------------------------------------------------------       *
'*  Button             The command button to register                  *
'*  Forecolor          The colour for the button text                  *
'*                                                                     *
'*  Returned Value -- Returns a Boolean value.  True if the            *
'*  registration succeeded and false if it failed.                     *
'*                                                                     *
'*  Remarks -- To change the button text colour, call RegisterButton   *
'*  again with the new colour.  This will not register the button      *
'*  twice.  It will only change the colour of an already registered    *
'*  button.                                                            *
'*                                                                     *
'*                                                                     *
'*                                                                     *
'*                                                                     *
'*  UnregisterButton:                                                  *
'*                                                                     *
'*  Used to stop colouring a button's text.                            *
'*                                                                     *
'*  Syntax -- UnregisterButton(<Button>)                               *
'*                                                                     *
'*  Part               Description                                     *
'*  ------------------------------------------------------------       *
'*  Button             The command button to unregister                *
'*                                                                     *
'*  Return Value -- Returns a Boolean value.  True if the              *
'*  unregistration succeeded and false if it failed.                   *
'*                                                                     *
'*  Remarks -- You don't need to unregister all button that were       *
'*  registered.  This will automatically be done when a form is        *
'*  closed.  This function is only provided so that a VB program may   *
'*  stop colouring a button before the form is closed.                 *
'*                                                                     *
'***********************************************************************

Private colButtons  As New Collection
Private Const KeyConst = "K"
Private Const PROP_COLOR = "SMDColor"
Private Const PROP_HWNDPARENT = "SMDhWndParent"
Private Const PROP_LPWNDPROC = "SMDlpWndProc"
Private Const GWL_WNDPROC As Long = (-4)
Private Const ODA_SELECT As Long = &H2
Private Const ODS_SELECTED As Long = &H1
Private Const ODS_FOCUS As Long = &H10
Private Const ODS_BUTTONDOWN As Long = ODS_FOCUS Or ODS_SELECTED
Private Const WM_DESTROY As Long = &H2
Private Const WM_DRAWITEM As Long = &H2B
Private Const VER_PLATFORM_WIN32_NT As Long = 2

Private Type RECT
   Left        As Long
   Top         As Long
   Right       As Long
   Bottom      As Long
End Type

Private Type SIZE
   cx          As Long
   cy          As Long
End Type

Private Type DRAWITEMSTRUCT
   CtlType     As Long
   CtlID       As Long
   itemID      As Long
   itemAction  As Long
   itemState   As Long
   hWndItem    As Long
   hDC         As Long
   rcItem      As RECT
   itemData    As Long
End Type

Private Type OSVERSIONINFO
  OSVSize         As Long
  dwVerMajor      As Long
  dwVerMinor      As Long
  dwBuildNumber   As Long
  PlatformID      As Long
  szCSDVersion    As String * 128
End Type

Private Declare Function CallWindowProc Lib "user32" _
    Alias "CallWindowProcA" _
   (ByVal lpPrevWndFunc As Long, _
    ByVal hWnd As Long, _
    ByVal msg As Long, _
    ByVal wParam As Long, _
    lParam As DRAWITEMSTRUCT) As Long

Private Declare Function GetParent Lib "user32" _
    (ByVal hWnd As Long) As Long

Private Declare Function GetProp Lib "user32" _
    Alias "GetPropA" _
   (ByVal hWnd As Long, _
    ByVal lpString As String) As Long

Private Declare Function GetTextExtentPoint32 Lib "gdi32" _
    Alias "GetTextExtentPoint32A" _
   (ByVal hDC As Long, _
    ByVal lpSz As String, _
    ByVal cbString As Long, _
    lpSize As SIZE) As Long

Private Declare Function RemoveProp Lib "user32" _
    Alias "RemovePropA" _
   (ByVal hWnd As Long, _
    ByVal lpString As String) As Long

Private Declare Function SetProp Lib "user32" _
    Alias "SetPropA" _
   (ByVal hWnd As Long, _
    ByVal lpString As String, _
    ByVal hData As Long) As Long

Private Declare Function SetTextColor Lib "gdi32" _
    (ByVal hDC As Long, _
    ByVal crColor 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 Declare Function TextOut Lib "gdi32" _
    Alias "TextOutA" _
   (ByVal hDC As Long, _
    ByVal x As Long, _
    ByVal y As Long, _
    ByVal lpString As String, _
    ByVal nCount As Long) As Long
    
Private Declare Function GetVersionEx Lib "kernel32" Alias "GetVersionExA" _
  (lpVersionInformation As Any) As Long
    


Private Function FindButton(sKey As String) As Boolean

   Dim cmdButton As CommandButton
   
   On Error Resume Next
   Set cmdButton = colButtons.Item(sKey)
   FindButton = (Err.Number = 0)

End Function


Private Function GetKey(hWnd As Long) As String

   GetKey = KeyConst & hWnd

End Function


Private Function ProcessButton(ByVal hWnd As Long, _
                               ByVal uMsg As Long, _
                               ByVal wParam As Long, _
                               lParam As DRAWITEMSTRUCT, _
                               sKey As String) As Long

   Dim cmdButton       As CommandButton
   Dim bRC             As Boolean
   Dim lRC             As Long
   Dim x               As Long
   Dim y               As Long
   Dim lpWndProC       As Long
   Dim lButtonWidth    As Long
   Dim lButtonHeight   As Long
   Dim lPrevColor      As Long
   Dim lColor          As Long
   Dim TextSize        As SIZE
   Dim sCaption        As String
   
   Const PushOffset = 2
   
   Set cmdButton = colButtons.Item(sKey)
   sCaption = cmdButton.Caption
   
   lColor = GetProp(cmdButton.hWnd, PROP_COLOR)
   lPrevColor = SetTextColor(lParam.hDC, lColor)
   
  'in Pixels/Logical Units
   lRC = GetTextExtentPoint32(lParam.hDC, sCaption, Len(sCaption), TextSize)
   
  'in Pixels/Logical Units
   lButtonHeight = lParam.rcItem.Bottom - lParam.rcItem.Top
   lButtonWidth = lParam.rcItem.Right - lParam.rcItem.Left
   
  'the button is pressed! Offset the text
  'so it looks like the button is pushed
    If ((lParam.itemState And ODS_BUTTONDOWN) = ODS_BUTTONDOWN) Then
        cmdButton.SetFocus
        DoEvents   'unneeded on XP - could use If Not IsWinXPPlus() Then DoEvents
        x = (lButtonWidth - TextSize.cx + PushOffset) \ 2
        y = (lButtonHeight - TextSize.cy + PushOffset) \ 2
    Else
        x = (lButtonWidth - TextSize.cx) \ 2
        y = (lButtonHeight - TextSize.cy) \ 2
    End If
   
  'get the default WndProc address
   lpWndProC = GetProp(hWnd, PROP_LPWNDPROC)
   
  'do the default button processing
   ProcessButton = CallWindowProc(lpWndProC, hWnd, uMsg, wParam, lParam)
   
  'put our text on the button
   bRC = TextOut(lParam.hDC, x, y, sCaption, Len(sCaption))
   
  'Restore the device context to the original color
   lRC = SetTextColor(lParam.hDC, lPrevColor)
   
ProcessButton_Exit:
   Set cmdButton = Nothing

End Function


Private Sub RemoveForm(hWndParent As Long)

   Dim hWndButton As Long
   Dim cnt As Integer
   
   UnsubclassForm hWndParent
   
   On Error GoTo RemoveForm_Exit
   
   For cnt = colButtons.Count - 1 To 0 Step -1
   
      hWndButton = colButtons(cnt).hWnd
      
      If GetProp(hWndButton, PROP_HWNDPARENT) = hWndParent Then
         RemoveProp hWndButton, PROP_COLOR
         RemoveProp hWndButton, PROP_HWNDPARENT
         colButtons.Remove cnt
      End If
      
   Next cnt
   
RemoveForm_Exit:

End Sub


Private Function UnsubclassForm(hWnd As Long) As Boolean

   Dim lpWndProC As Long
   
   lpWndProC = GetProp(hWnd, PROP_LPWNDPROC)
   
   If lpWndProC = 0 Then
   
      UnsubclassForm = False
      
   Else
   
      Call SetWindowLong(hWnd, GWL_WNDPROC, lpWndProC)
      RemoveProp hWnd, PROP_LPWNDPROC
      UnsubclassForm = True
      
   End If

End Function


Private Function ButtonColorProc(ByVal hWnd As Long, _
                                 ByVal uMsg As Long, _
                                 ByVal wParam As Long, _
                                 lParam As DRAWITEMSTRUCT) As Long

   Dim lpWndProC       As Long
   Dim bProcessButton  As Boolean
   Dim sButtonKey      As String

   bProcessButton = False      'Assume default processing

   If (uMsg = WM_DRAWITEM) Then
   
     'Do we have this button? To find out, just
     'try to reference the item in the collection.
     'If it's there, we own the button.  If it's
     'not there, we'll get an error.
      sButtonKey = GetKey(lParam.hWndItem)
      bProcessButton = FindButton(sButtonKey)
   
   End If
   
   
   If bProcessButton Then
   
      ProcessButton hWnd, uMsg, wParam, lParam, sButtonKey
      
   Else
   
      lpWndProC = GetProp(hWnd, PROP_LPWNDPROC)
      ButtonColorProc = CallWindowProc(lpWndProC, hWnd, uMsg, wParam, lParam)

      If uMsg = WM_DESTROY Then RemoveForm hWnd
      
   End If

End Function


Public Function RegisterButton(Button As CommandButton, _
                               Forecolor As Long) As Boolean

   Dim hWndParent      As Long
   Dim lpWndProC       As Long
   Dim sButtonKey      As String

  'Make the colButtons key for the button
   sButtonKey = GetKey(Button.hWnd)
   
  'If we already own the button, just change the
  'color otherwise we need to process the whole thing.
   If FindButton(sButtonKey) Then
   
      SetProp Button.hWnd, PROP_COLOR, Forecolor
      Button.Refresh
      
   Else
   
     'Get the handle to the buttons parent form.
      hWndParent = GetParent(Button.hWnd)
   
     'If we can't find a parent form, report a
     'problem and get out.
      If (hWndParent = 0) Then
         RegisterButton = False
         Exit Function
      End If
   
     'found the parent, gather all of the necessary
     'button values and add it to the collection.
      colButtons.Add Button, sButtonKey
      SetProp Button.hWnd, PROP_COLOR, Forecolor
      SetProp Button.hWnd, PROP_HWNDPARENT, hWndParent
      
     'Determine if we've already subclassed this form.
      lpWndProC = GetProp(hWndParent, PROP_LPWNDPROC)
   
     'It's a new form.  Subclass it and add the
     'Window proc address to the collection.
      If (lpWndProC = 0) Then
         lpWndProC = SetWindowLong(hWndParent, _
         GWL_WNDPROC, AddressOf ButtonColorProc)
         SetProp hWndParent, PROP_LPWNDPROC, lpWndProC
      End If
   
   End If
   
   RegisterButton = True

End Function


Public Function UnregisterButton(Button As CommandButton) As Boolean

   Dim hWndParent As Long
   Dim sKeyButton As String

   sKeyButton = GetKey(Button.hWnd)

   If (FindButton(sKeyButton) = False) Then
      UnregisterButton = False
      Exit Function
   End If

   hWndParent = GetProp(Button.hWnd, PROP_HWNDPARENT)
   UnregisterButton = UnsubclassForm(hWndParent)

   colButtons.Remove sKeyButton
   RemoveProp Button.hWnd, PROP_COLOR
   RemoveProp Button.hWnd, PROP_HWNDPARENT
   
End Function


Private Function IsWinXPPlus() As Boolean

  'returns True if running WinXP (NT5.1) or later
   Dim osv As OSVERSIONINFO

   osv.OSVSize = Len(osv)

   If GetVersionEx(osv) = 1 Then
   
      IsWinXPPlus = (osv.PlatformID = VER_PLATFORM_WIN32_NT) And _
                    (osv.dwVerMajor >= 5 And osv.dwVerMinor >= 1)

   End If

End Function
 Form Code
To a form, add a control array of command buttons (Command1(0) through Command1(9)) and a control array of option buttons (Option1(0) through Option1(9)). Set the Style property of all Command1() buttons to 1-Graphical. Add the following code:

Option Explicit
'non-vb colours
Const vbDarkRed = &H90&
Const vbDarkBlue = &H900000

'consts for the Command1 button control array
Const nDefault = 0
Const nRed = 1
Const nGreen = 2
Const nBlue = 3
Const nYellow = 4
Const nMagenta = 5
Const nCyan = 6
Const nWhite = 7
Const nDkBlue = 8
Const nDkRed = 9


Private Sub Command2_Click()

   Unload Me
   
End Sub


Private Sub Form_Load()

  'create the coloured buttons
   RegisterButton Command1(nRed), vbRed
   RegisterButton Command1(nGreen), vbGreen
   RegisterButton Command1(nBlue), vbBlue
   RegisterButton Command1(nYellow), vbYellow
   RegisterButton Command1(nMagenta), vbMagenta
   RegisterButton Command1(nCyan), vbCyan
   RegisterButton Command1(nWhite), vbWhite
   RegisterButton Command1(nDkBlue), vbDarkBlue
   RegisterButton Command1(nDkRed), vbDarkRed

  'set the default backcolour
   Option1(0).Value = True
   
End Sub


Private Sub Option1_Click(Index As Integer)

   Dim clrref As Long

  'set the backcolour
   Select Case Index
      Case 0: clrref = vbButtonFace
      Case 1: clrref = vbApplicationWorkspace
      Case 2: clrref = vbBlack
      Case 3: clrref = vbWhite
      Case 4: clrref = vbRed
      Case 5: clrref = vbGreen
      Case 6: clrref = &H900000
      Case 7: clrref = vbCyan
      Case 8: clrref = vbMagenta
      Case 9: clrref = vbYellow
   End Select
   
   Command1(nRed).BackColor = clrref
   Command1(nGreen).BackColor = clrref
   Command1(nBlue).BackColor = clrref
   Command1(nYellow).BackColor = clrref
   Command1(nMagenta).BackColor = clrref
   Command1(nCyan).BackColor = clrref
   Command1(nWhite).BackColor = clrref
   Command1(nDkBlue).BackColor = clrref
   Command1(nDkRed).BackColor = clrref
   
End Sub
 Comments
Save the project and start with full compile to check for errors.  The buttons should be coloured as shown in the illustration, and selecting option buttons will show the effect of the new forecolor in combination with a non-standard windows button face background.

NOTE 1: If you move the code to set the button forecolor from the load event to another event that occurs after the form has been displayed, you will need to refresh the button (e.g. Command1.Refresh) in order to see the change resulting from the call(s) to RegisterButton.

NOTE 2:  I did some testing of the original code on XP and noticed that when the button was pressed the text appeared shadowed. The success of this demo relies on redrawing the button caption overtop the existing black caption text; I was seeing the coloured text drawn in the 'normal' (non-offset) position even when the button was depressed while the system-drawn black button text was also being drawn in the offset position giving the 'shadow' effect.

I tracked the problem to the failure of the original ProcessButton's "If (lParam.itemAction = ODA_SELECT) And (lParam.itemState = ODS_BUTTONDOWN) Then ..." condition to execute. In examining the values of the .itemAction and .itemState members at that point when the button was pushed, I found they were not the same values as I had received using pre-XP versions of Windows. On XP itemAction was returning 1 (not the expected 2), and itemState was returning &H311, not &H11 as expected. 

VBnet visitor Rui Trigueiros correctly pointed out that &H311 was a combination of ODS_FOCUS, ODS_SELECTED, and two Win version 5 values - ODS_NOACCEL and ODS_NOFOCUSRECT. These latter values were intermittently set depending on whether the button had already received focus. A mod to the itemState test - which appears to work on all systems - has therefore been made to the ProcessButton code which also removed the lParam.itemAction test as through trial and error it appears this test was not necessary.

As I do not have access to all OS versions with which to test this code I am soliciting results from visitors (via the Send Comments link on the left menu pane) who can confirm or deny the code works as expected on the OS version marked as [unknown] below.


 
Windows version:   Revised text offset drawing confirmed as working on:

 
Windows 2003   YES
Windows XP Pro   YES
Windows XP Home   YES
Windows 2000   YES
Windows NT4   YES
Windows ME   YES
Windows SE   YES
Windows 98   YES
Windows 95b (OSR2)      [unknown]
Windows 95   [unknown]

 
 

PayPal Link
Make payments with PayPal - it's fast, free and secure!

 
 
 
 

Copyright 1996-2011 VBnet and Randy Birch. All Rights Reserved.
Terms of Use  |  Your Privacy

 

Hit Counter