Re: Tree View Control state image list

From:

David Connet <connet@entelos.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Thu, 28 Jun 2007 08:49:46 -0500

Message-ID:

<E_idndWaK9nnIR7bnZ2dnUVZ_sKunZ2d@comcast.com>

Something that's bugging me on this is that the OP said they turned on
the checkbox option on the control - and then is managing the checkboxes
themself. I seem to remember that's a problem - ah yes (just looked over
some code) - my control actually ASSERTs that (!(GetStyle() &
TVS_CHECKBOXES)) in the presubclasswindow code.

When you tell Windows that the tree has checkboxes, it tries to manage
the checkmark resource. Which is exactly what you DON'T want since you
have additional states to handle.

Also, do not use the SetCheck api. You'll need to call GetItemState
(handle, TVIS_STATEIMAGEMASK)/SetItemState(handle, INDEXTOSTATEIMAGEMASK
(state_index), TVIS_STATEIMAGEMASK). (And as an added bonus, you can have
items with no checkbox at all by setting image 0. Our tree had a need for
that since there are some items in the tree that cannot be selected, as
opposed to items whose state cannot be changed.)

Dave Connet

"Tom Serface" <tom.nospam@camaswood.com> wrote in
news:F827CC9A-4192-4290-826C-36E9A5A85D6C@microsoft.com:

I've never tried to do this, but did you really mean ILC_COLOR24
rather than ILC_COLOR4?

You may also find this article interesting:

http://www.codeproject.com/treectrl/vtree.asp

Tom

"Rob" <Rob@discussions.microsoft.com> wrote in message
news:2D64D5EB-11E9-41A0-A56D-7AA3EB3F8527@microsoft.com...

I'm trying to implement a tree view in an MFC wizard property sheet
that has
check boxes that can be dimmed. In order to do this, I've created an
image list that has the check boxes in each of their 4 possible
combinations of unchecked/checked and enabled/disabled (as well as a
blank image at index 0).
However, when I set this image list as the tree view control's state
image list, all I see are blank images where the check boxes should
be. (I use the
correct state indices when I add the various items. I'm using
commctl32 version 5.80 and Visual Studio 2005, so according to the
documentation, I should be able to have a state image list without a
main image list.

The tree control is set with the Check Boxes property set to TRUE.
The bitmap resource that I'm using is a 16-colour bitmap with a white
background
that I want to appear as transparent. (I'm using ::LoadImage() and
CImageList::Add() instead of CImageList::Create() in the code,
because I want
the greys in the bitmap (in the 'disabled' images) to map to the
system 3D colours.)

Sample code appears below:

class CMyPropPage : public CPropertyPage
{
     .
     .
     .
   CTreeCtl mMyTree;
     .
     .
     .
}

BOOL CMyPropPage::OnInitDialog()
{
   CImageList ImageList;
   HBITMAP hBitmap;
   HTREEITEM hParent, hTreeItem;
     .
     .
     .
   ImageList.Create(16, 16, ILC_COLOR4, 0, 5);
   hBitmap = (HBITMAP)::LoadImage(theApp.hInstance,
MAKEINTRESOURCE(IDB_STATEIMG), IMAGE_BITMAP, 80, 16,
LR_LOADMAP3DCOLORS);
   ImageList.Add(CBitmap::FromHandle(hBitmap), RGB(255, 255, 255));
   mMyTree.SetImageList(&ImageList, GVSIL_STATE);
     .
     .
     .
   hTreeItem = mMyTree.InsertItem(TVIF_STATE | TVIF_TEXT, _T("Item
   1"), 0,
0, INDEXTOSTATEIMAGEMASK(1), TVIS_STATEIMAGEMASK, 0, TVI_ROOT,
TVI_LAST);
   hTreeItem = mMyTree.InsertItem(TVIF_STATE | TVIF_TEXT, _T("Item
   2"), 0,
0, INDEXTOSTATEIMAGEMASK(2), TVIS_STATEIMAGEMASK, 0, TVI_ROOT,
TVI_LAST);
   hTreeItem = mMyTree.InsertItem(TVIF_STATE | TVIF_TEXT, _T("Item
   3"), 0,
0, INDEXTOSTATEIMAGEMASK(1), TVIS_STATEIMAGEMASK, 0, TVI_ROOT,
TVI_LAST);
   hParent = hTreeItem;
   hTreeItem = mMyTree.InsertItem(TVIF_STATE | TVIF_TEXT, _T("Item
   3.1"),
0, 0, INDEXTOSTATEIMAGEMASK(1), TVIS_STATEIMAGEMASK, 0, hParent,
TVI_LAST);
     .
     .
     .
}

Can anybody tell me what I'm doing wrong? How do I get the check box
images
to appear?