Re: check boxes in a tree

From:
"GT" <a@b.c>
Newsgroups:
microsoft.public.vc.mfc
Date:
Thu, 20 May 2010 17:50:31 +0100
Message-ID:
<4bf56855$0$24682$c3e8da3@news.astraweb.com>
"David Lowndes" <DavidL@example.invalid> wrote in message
news:s3nav55nn11r94tmu4rsffs5fe244mcund@4ax.com...

on a CDialog based dialog, I have a CTreeCtrl based control that contains
a
flat list of HTREEITEMs, each with a checkbox. When I add items to it
during
OnInitDialog, none of the checkboxes appear ticked, even though I set some
of them checked and stepping through the code suggests that they should
be.


That's a "quirk" of the control :)

The Platform SDK docs under the topic "Tree View Control Window
Styles" says:

"If you want to use this style, you must set the TVS_CHECKBOXES style
with SetWindowLong after you create the treeview control, and before
you populate the tree. Otherwise, the checkboxes might appear
unchecked, depending on timing issues.
"

Something like this is necessary:

BOOL CMyDialog::OnInitDialog()
{
CDialog::OnInitDialog();

/* Remove the style */
mTree.ModifyStyle( TVS_CHECKBOXES, 0 );
/* Now explicitly set it */
mTree.ModifyStyle( 0, TVS_CHECKBOXES );

HTREEITEM aItem = mTree.InsertItem("AAA");
mTree.SetCheck(aItem);

return TRUE;
}


The remove and add TVS_CHECKBOXES did the trick! Thanks.

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