detecting when another window has been selected

I've been puzzling over this one for a day or so, I want to change the header bar of a window to black, but the only way I've been able to do this is to call the GetSysColor, SetSysColors. Now I want to restore the original colors whenever the user moves off the window. THe code I have catches it when you exit or minimize, but when you just click on another window it doesn't work.. Any suggestions?

Private Declare Function GetSysColor Lib "user32.dll" (ByVal nIndex As Long) As Long
Private Declare Function SetSysColors Lib "user32.dll" (ByVal cElements As Long, lpaElements As Long, lpaRgbValues As Long) As Long

Const COLOR_ACTIVECAPTION = 2
Const COLOR_GRADIENTACTIVECAPTION = 27
Const COLOR_GRADIENTINACTIVECAPTION = 28
Const COLOR_INACTIVECAPTION = 3

Dim colorNames(0 To 3) As Long ' identifiers of the system colors to change
Dim colorRGB(0 To 3) As Long ' RGB values of the system colors to change
Dim colorRGB2(0 To 3) As Long ' RGB values of the system colors to change

Dim retval As Long ' generic return value

Private Sub Form_Load()
CollectColors
End Sub
' Get the RGB values of the colors used in title bars.
Function CollectColors()
colorNames(0) = COLOR_ACTIVECAPTION
colorNames(1) = COLOR_GRADIENTACTIVECAPTION
colorNames(2) = COLOR_INACTIVECAPTION
colorNames(3) = COLOR_GRADIENTINACTIVECAPTION

colorRGB(0) = GetSysColor(COLOR_ACTIVECAPTION)
colorRGB(1) = GetSysColor(COLOR_GRADIENTACTIVECAPTION)
colorRGB(2) = GetSysColor(COLOR_INACTIVECAPTION)
colorRGB(3) = GetSysColor(COLOR_GRADIENTINACTIVECAPTION)
Dim state As Boolean
End Function

Private Sub Form_Resize()

If Me.WindowState = vbNormal Then
'Change colors to black
retval = SetSysColors(4, colorNames(0), colorRGB2(0))
state = True
ElseIf Me.WindowState = vbMinimized Then
'Change colors back
retval = SetSysColors(4, colorNames(0), colorRGB(0))
state = False
End If

End Sub

Private Sub Form_Unload(Cancel As Integer)
'reset colors
retval = SetSysColors(4, colorNames(0), colorRGB(0))
End Sub

Easy solution - not guaranteed to be the best solution.

GetActiveWindow

Within a timer event check the handle that this function returns and compare it to the window with the black bar. If it is different, then you know that the window has lost focus and therefor you may change the color back.

yeah I tried that one too, but it was way too system heavy though, what with the checks going on all the time:
if not the focus window then reset colors
else set colors black

Have you tried subclassing the window? Do a debug.print of all the messages and see if you get a message when the window loses focus. If Windows can change the title bar when a window loses focus, then you can just as efficiently. :)

There's an OCX at Merrion Computing that is exactly what you need.

Add it to your app's main form, and in the form load:
Private Sub Form_Load()

Me.VBEventWindow1.ParentForm = Me.hWnd

End Sub

Then put the code to turn your app's caption bar back to the previous colour in:
Private Sub VBEventWindow1_ActiveApplicationChanged(ByVal ActivatingThisApp As Boolean, ByVal hThread As Long, Cancel As Boolean)

End Sub

This event is fired whenever the user leaves or enters your application.

HTH,
Merrion Computing Ltd

awesome thanks so much!