Solved

How to disable ComboBox automatic scrolling?

Posted on 2000-03-26
9
481 Views
Last Modified: 2013-11-20
I have class MyComboBox. When I select an item from a ListBox, ComboBox is scrolled automatically that selected item is the first on ListBox. How could I disable it?
I tried to do it in OnDropDown, OnLButtonDown in OnClouseUp. Always without success!
I would like to control scrolling by my code!

Thanks all!
0
Comment
Question by:si124
  • 5
  • 4
9 Comments
 
LVL 1

Accepted Solution

by:
yarond earned 100 total points
Comment Utility
Well, it's not very elegant, but it will work.
The combobox scrolls the drop-down listbox to the selected item. So what you can do is on the OnDropDown use SetCurSel(-1) which will clear the selection.
However, if you want the selected item to remain selected when you close the drop-down without selecting a different one, before using SetCurSel(-1) use GetCurSel() and keep the return value, and then on OnCloseUp check if GetCurSel()==CB_ERR, and if so (no new item was selected) use SetCurSel(m_PrevSelection).
It will also work properly on the first run because CB_ERR==-1 so if nothing was selected no harm is done. Although it would be much nice to search for this condition on the OnDropDown and not count on it...
0
 

Author Comment

by:si124
Comment Utility
Thank you very much for your help.
I managed to control scrolling by myself.

I would like to leave selected text in EditBox on DropDown. In this case EditBox is empty (unusal).
Is it possible to fix it?

Thanks!
0
 
LVL 1

Expert Comment

by:yarond
Comment Utility
I found a totally different solution, which is IMHO much better, and answers all your requirements (that I know of).
In the OnDropDown, assuming you have a CComboBox control named m_Combo, use either:
::PostMessage(m_Combo.m_hWnd,CB_SETTOPINDEX,0,0);
or:
m_Combo.PostMessage(CB_SETTOPINDEX,0,0);
If you use PostMessage and not SendMessage it gets processed only after the dropdown operation is finished, and so it scrolls to the top position.
0
 

Author Comment

by:si124
Comment Utility
I used this option before!!!
I send my own WM_USER+1 message and in it I scroll down ListBox to right position.
I can't use SetTopIndex because I have header control on the top of ListBox, so I have to leave it on the top!
Your last solution was OK, except the problem of empty EditBox!
Is there any other possibility to solve my problem!

Thanks!



0
6 Surprising Benefits of Threat Intelligence

All sorts of threat intelligence is available on the web. Intelligence you can learn from, and use to anticipate and prepare for future attacks.

 

Author Comment

by:si124
Comment Utility
I have to repair myself. I meant Post WM_USER+1 message!
0
 
LVL 1

Expert Comment

by:yarond
Comment Utility
One rather ugly option would be to put a different editbox on top of the combobox's editbox, and in OnDropDown, copying the selected item to it, making it visible, and only then clearing the selection.
But I don't exactly understand how does the header control prevent you from using SetTopIndex. Where exactly is the header control placed, and what happens to it when you use SetTopIndex?
0
 

Author Comment

by:si124
Comment Utility
My header control is child window of ListBox. When I use SetTopIndex, windows is scrolled so header control disappears from the view.
0
 
LVL 1

Expert Comment

by:yarond
Comment Utility
I can't think of a better solution for you right now. I'll withdraw my answer so someone else might be able to help you.
0
 

Author Comment

by:si124
Comment Utility
In any case thank you very very much for your help!!!!!
0

Featured Post

Do You Know the 4 Main Threat Actor Types?

Do you know the main threat actor types? Most attackers fall into one of four categories, each with their own favored tactics, techniques, and procedures.

Join & Write a Comment

Suggested Solutions

Introduction: Displaying information on the statusbar.   Continuing from the third article about sudoku.   Open the project in visual studio. Status bar – let’s display the timestamp there.  We need to get the timestamp from the document s…
Introduction: The undo support, implementing a stack. Continuing from the eigth article about sudoku.   We need a mechanism to keep track of the digits entered so as to implement an undo mechanism.  This should be a ‘Last In First Out’ collec…
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
This demo shows you how to set up the containerized NetScaler CPX with NetScaler Management and Analytics System in a non-routable Mesos/Marathon environment for use with Micro-Services applications.

772 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

10 Experts available now in Live!

Get 1:1 Help Now