Hello,

I want to read a bmp from a resource dll and make the background transparent
. Therfore I use the code below . The problem is that the code below is
integrated in a VB ActiveX Control , and for some reason it's pretty slow .
Meaning that the user can see the screen flikker from the TempColor to the
TransColor while the SetSysColor is done .

Is there a possibility to change this behaviour ? Without the flikkering ?

Or does somebody have a nice alternitive to put BMP's with transcolor in a
Image List ?

*** open library (hMyDLL)

nLTempColor = GetSysColor(COLOR_WINDOW)

    Call SetSysColors(1, COLOR_WINDOW, nMyTransColor)
*** all the active windows have a grey backcolor
    '
    If hMyDLL <> 0 Then
        '
        hLBmp = LoadImage(hMyDLL, sPName, IMAGE_BITMAP, nPX, nPY,
LR_LOADTRANSPARENT)

        Call SetSysColors(1, COLOR_WINDOW, nLTempColor)
*** all the active windows return to normal

        Set iPic = BmpToPicture(hLBmp)

        If Not (iPic Is Nothing) Then

            nMyIndexCount = nMyIndexCount + 1

            Call myIl.ListImages.Add(nMyIndexCount, sPName, iPic)

Hoping to hear from you .

Filip W.

This is a really bad way to do this!  I don't think you can avoid the
flicker, because it's all of windows doing it...

The imageList has a method, I can't remember if it's called .Draw or
Render (maybe it has both, but only one works properly?  I forget,
it's been awhile since I did this and I'm too lazy to look it up...)
that'll draw the image with transparency.

If that's not enough of a hint, repost your question in
winapi.graphics and Mike S.  will answer it for sure.

Jim Deutch

I'm by no means an expert on image list controls, but I believe the code
you're looking for here is:
ImageList1.ListImages(1).Draw Form1.hDC, 0, 0, imlTransparent
However if possible draw everything to an off-screen buffer first then once
everything's been drawn blit it all over to the render DC, this way you'll
avoid the flicker cause by it's 2-stage blit.  Have a look at the "Blitting
with transparency" tutorial on my site for more information on this, also
I'd imagine that this is most likely using TransparentBlt() behind the
scenes which is known to have a resource leak which can cause problems when
it's called recursively, for this I've written a replacement on my site in
the ChromaBlt() library which does exactly the same thing.

It's already here but I wasn't sure on the answer since I don't often work
with the controls, guess now I have to answer though, huh? ;)
Hope this helps,

    Mike

 -- EDais --

 - Microsoft Visual Basic MVP -
WWW: Http://EDais.earlsoft.co.uk/

Try this:

Const ILD_TRANSPARENT = 1
Const IMAGE_BITMAP = 0
Const CLR_DEFAULT = &HFF000000
Const LR_CREATEDIBSECTION = &H2000

Private Declare Function ImageList_Draw Lib "comctl32.dll" _
  (ByVal himl As Long, ByVal index As Long, ByVal hDCDest As Long, _
   ByVal x As Long, ByVal y As Long, ByVal flags As Long) As Long
Private Declare Function ImageList_SetOverlayImage Lib "comctl32.dll" _
  (ByVal himl As Long, ByVal iImage As Long, ByVal iOverlay As Long) As
Long
Private Declare Function ImageList_Destroy Lib "comctl32.dll" _
  (ByVal himl As Long) As Long
Private Declare Function ImageList_LoadImage Lib "comctl32.dll" _
  (ByVal hi As Long, ByVal lpBmp As String, ByVal cx As Long, _
   ByVal cGrow As Long, ByVal crMask As Long, ByVal uType As Long, _
   ByVal uFlags As Long) As Long

'Transparent color is topmost, leftmost pixel in image.
  himg = ImageList_LoadImage(hDLL, sPName, 0, 0, CLR_DEFAULT,
IMAGE_BITMAP, LR_CREATEDIBSECTION)

  lret = ImageList_SetOverlayImage(himg, 0, 1)

  lret = ImageList_Draw(himg, 0, picDisplay.hdc, 0, 0, ILD_TRANSPARENT)
  picDisplay.Refresh

  lret = ImageList_Destroy(himg)

--
Richard Mason