Click here to Skip to main content
13,346,895 members (29,527 online)
Click here to Skip to main content
Add your own
alternative version


65 bookmarked
Posted 27 Jan 2004


, 2 Feb 2004
Rate this:
Please Sign up or sign in to vote.
A treeview control that drops down much like a combobox.

Sample Image


The ComboBoxTree control expands on Gevik Babakhani's DropDown Treeview control. Nearly 85% of the code has been rewritten. This updated control provides the following enhancements:

  • Treeview can be sized beyond the width of its parents and the form.
  • The sizing grip functionality is more consistent with standard Windows sizing grips.
  • Node selection populates the box when it is a root node, the SelectionSeparator property assigns the separator (i.e. a SelectionSeperator that is a period '.' would generate something like: Node0.subnode1.subnode2.rootnode).
  • Better design-time support including the standard treeview WYSIWYG editor.
  • The selected node box is editable and accessible as a property - however there is no validation on this value when set manually.
  • Simplified, by using regions and less method calls.

Please feel free to post comments, questions or criticism. This is my first Windows control, so feedback is appreciated.


I needed a control for a project that required multiple treeviews but had very limited form space. When I found Gevik's DropDown TreeView, I was relieved to find what I was looking for but soon ran into problems that required attention and hours of code updating.

Originally, I didn't intend to redistribute the updated control, but I wanted to give back as a way of saying thanks. Thanks goes out to The Code Project and the original author - thanks Gevik Babakhani ;-)

To use the control, simply add the ComboBoxTree.dll file to your toolbox and drop the control onto your form. The control should provide most of the treeview functionality you require.

Points of Interest

I was able to get around the "sizing beyond parent" problem by adding the treeview to its own borderless form. My next problem involved making the sizing grip work correctly. I was able to get this going by calculating the offset of the mouse within the sizing grip along with the absolute mouse position and the location of the form containing the treeview. My final big problem was the sizing grip when scroll bars showed. Disabling scroll bars wasn't a solution so my only alternative was to add a margin of space on the bottom and right-hand side. A bit different but definitely functional!


  • 01/26/04 Version 1.0 submitted.
  • 02/02/04 Version 1.2 submitted, changes include:
    • Text property is now overridden.
    • AbsoluteChildrenSelectableOnly property option now available, users can now select end nodes only or all nodes.
    • Public ValidateText method now available to validate manually entered text.
    • SelectionSeparator now called BranchSeparater.
    • Minor toolbox category changes.


This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here


About the Author

Gabe Anguiano
United States United States
No Biography provided

You may also be interested in...

Comments and Discussions

BugSize Bug Pin
Member 1145332622-Dec-15 2:55
memberMember 1145332622-Dec-15 2:55 
QuestionNo NodeSelectEventHandler event? Pin
locketine17-Dec-12 15:07
memberlocketine17-Dec-12 15:07 
AnswerRe: No NodeSelectEventHandler event? Pin
Member 1145332622-Dec-15 3:16
memberMember 1145332622-Dec-15 3:16 
QuestionCan't change size Pin
MVictorL18-Nov-12 23:09
memberMVictorL18-Nov-12 23:09 
QuestionHandling the Enter key Pin
Member 390355925-Oct-12 11:55
memberMember 390355925-Oct-12 11:55 
QuestionHow to show image of the selected tree item in combobox Pin
Rui Frazao9-Jun-10 7:07
memberRui Frazao9-Jun-10 7:07 
GeneralCheckbox With Every Node Pin
Farid_Bilal26-Feb-09 21:58
memberFarid_Bilal26-Feb-09 21:58 
Hi gabe First Of All Great Great Article..
I am new to This One .. I am using ur control with little bit modification and conversion in . now i want a checkbox with every node (parents/childs) so the selected text coe with only the nodes with checked checkboxes . i treid alot but didnt got any solution coz there is no checkboxes property available with the control as the normal window contrl treeview components contains .. could u please give any suggestion,solution or any idea ???

Thanks In Advance

QuestionHow to populate tree with data from datatable ? Pin
loverboy2312-Jul-08 4:49
memberloverboy2312-Jul-08 4:49 
QuestionHow can i get DropDownStyle like combobox? Pin
Member 137660010-Apr-08 4:07
memberMember 137660010-Apr-08 4:07 
GeneralBranchSeparator as String, DropDownHeight, ... Pin
fraveu27-Sep-07 10:53
memberfraveu27-Sep-07 10:53 
GeneralRe: BranchSeparator as String, DropDownHeight, ... Pin
fraveu27-Sep-07 10:55
memberfraveu27-Sep-07 10:55 
GeneralFlatStyle System Pin
jake07223-Aug-07 11:30
memberjake07223-Aug-07 11:30 
GeneralRe: FlatStyle System Pin
LAcike@sk1-Jul-08 0:40
memberLAcike@sk1-Jul-08 0:40 
GeneralAfterSelect event Pin
mayank_max104-Jun-07 7:50
membermayank_max104-Jun-07 7:50 
GeneralRe: AfterSelect event Pin
mayank_max4-Jun-07 10:07
membermayank_max4-Jun-07 10:07 
GeneralRe: AfterSelect event Pin
mayank_max4-Jun-07 10:13
membermayank_max4-Jun-07 10:13 
GeneralRe: AfterSelect event Pin
JossGP12-Oct-07 0:41
memberJossGP12-Oct-07 0:41 
QuestionHow to sort the ComboBoxTree Pin
satisht23-May-07 21:18
membersatisht23-May-07 21:18 
GeneralNeed this in [modified] - no longer needed Pin
Vortran9-Oct-06 11:51
memberVortran9-Oct-06 11:51 
GeneralBug Deteced !! Pin
H1berto Ferreira3-Jan-06 2:44
memberH1berto Ferreira3-Jan-06 2:44 
Generalform lostfocus problem Pin
TurboWang10-Mar-04 15:50
memberTurboWang10-Mar-04 15:50 
GeneralRe: form lostfocus problem Pin
Gabe Anguiano12-Mar-04 10:59
memberGabe Anguiano12-Mar-04 10:59 
GeneralExcellent ! Pin
BillWoodruff10-Feb-04 16:52
memberBillWoodruff10-Feb-04 16:52 
GeneralButton on title bar Pin
sylvain22223-Feb-04 4:05
membersylvain22223-Feb-04 4:05 
GeneralRe: Button on title bar Pin
asm433-Feb-04 8:10
memberasm433-Feb-04 8:10 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

Permalink | Advertise | Privacy | Terms of Use | Mobile
Web03 | 2.8.180111.1 | Last Updated 3 Feb 2004
Article Copyright 2004 by Gabe Anguiano
Everything else Copyright © CodeProject, 1999-2018
Layout: fixed | fluid