CImageList transparency

Posted on 2004-12-01
Medium Priority
Last Modified: 2008-02-01
I have a list of images and it is displayed like so:

| White space                     |
|                                       |
|  The image is here           |
|                                       |
|                                       |
| White space                     |

Now, if I select the image I want my background bitmap to change colour, but I still have the white space displayed with the thumbnail image and it looks rubbish.

I want the white space to be the same colour as the background so transparency would be best but how do I do this?

Do I have to set some flags when createing the image list and also on the Draw code. At the moment my code looks like:

// Create the list
Parent->m_ImageListThumb->Create(THUMBNAIL_WIDTH, THUMBNAIL_HEIGHT, ILC_COLOR24, 0, 1 );

// draw the image
Parent->m_ImageListThumb->Draw(&dc, pCurrentImage->whereInTheCImageList, CPoint(Rect.left+4,Rect.top+4), ILD_NORMAL);

So how do I do this?


Question by:jeffreyg
1 Comment
LVL 31

Accepted Solution

Zoppo earned 500 total points
ID: 12717109
Hi jeffreyg,

this should do it:

1. Create the Imagelist with ILC_MASK flag, i.e.
Parent->m_ImageListThumb->Create(THUMBNAIL_WIDTH, THUMBNAIL_HEIGHT, ILC_COLOR24 | ILC_MASK, 0, 1 );

2. When adding images to the list you need to specify the mask-color (i.e. RGB( 255, 255, 255 ) if you want the white parts of your image to be transparent)
Another possibility is to create a mask image manually (i.e. needed if you don't want each white pixel to be transparent) .

3. Use ILD_TRANSPARENT in call to CImageList::Draw() instead of ILD_NORMAL

Hope that helps,


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