TreeView and DragAndDrop in Win32

Question

0.00/5 (No votes)

See more:

I have a Win32 C++ (non-MFC) application which uses a TreeView control. The control is created with the TVS_DISABLEDRAGDROP style not set. My expectation was that in this case I would receive a TVN_BEGINDRAG notification and could handle the drag operation from that handler. (Moreover, this used to work -- it has been part of released product code for several years and worked fine until recently. At some point, something changed.)

Now, I never receive a TVN_BEGINDRAG message. I am able to use a tree item as the source of a drag, but to do so, I need to detect the drag inside my mouse-down handler, instead of in the TVN_BEGINDRAG handler.

Can anyone explain why this might be the case? Although I have a work around in place, I would like to understand why this work-around is necessary.

Thank you.

Rick Aurbach
Aurbach & Associate, Inc.

Posted 27-Jun-12 9:54am

RickAurbach

Add a Solution

Comments

Sergey Alexandrovich Kryukov 27-Jun-12 16:01pm

Do you also handle mouse events properly? Please see:
http://support.microsoft.com/kb/214814
Yes, I understand your question...
--SA

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

RickAurbach · Answer 1 · 2012-06-27T10:22:00

Sergey,

Thanks for your rapid response, but the solution shown in the support article doesn't help much. Since the notification never happens, there's the g_fdragging flag never gets set, so there's no way for the logic implemented in the other handlers to work.

I'm basically handling the other drag logic using the same methodology I use everywhere else in my program. (This tree view is only one of many different types of objects which can be either drag sources or targets or both.) My implementation of the appropriate handlers works a bit differently, but accomplishes the same purposes as the code from the support article.

This still leaves the question open -- why don't I get the notification??

Rick