Click here to Skip to main content
11,645,889 members (76,835 online)
Click here to Skip to main content

WPF MultiSelect TreeView Sample

, 23 Mar 2008 CPOL 89.4K 3.7K 30
Rate this:
Please Sign up or sign in to vote.
Shows how to add multi-select capabilities to WPF TreeView control
MultiSelectTreeView

Introduction

WPF TreeView control does not give developers an ability to multi-select the nodes of the tree. This article shows a very simple example that simulates multi-select capability for a WPF TreeView control. I say "simulate" because it discards the WPF select mechanism and replaces it with its own.

Ideally another user control called, say MultiSelectTreeView, should be created and packed in a separate DLL, but since I do not have much time to spend on it, I simply showed how to do it by modifying the code in the main Window class.

To multi-select, you should use the left ctrl key on your keyboard together with the mouse. The shift key and ctrl-A multi-select functions were not added (again for the lack of time), but can be added in exactly the same manner.

Simulating the Multi-Selection

As stated above, we disable the WPF selection and, instead use our own selection mechanism, according to which, all TreeViewItem elements that have been selected are stored in selectedItems set. The set is simulated by a Dictionary with null values.

The selected items change their Background and Foreground properties to Brushes.Black and Brushes.White correspondingly.

If LeftCtrl key is not pressed, then, before selecting an item, we clean all the previous selections. If LeftCtrl key is pressed, the previous selections are not cleaned.

Using the Code

The top level code is located in MyTreeView_SelectedItemChanged function and called when SelectedItemChanged event is fired on the TreeView.

First, prevent WPF selection:

treeViewItem.IsSelected = false;

Then, if LeftCtrl is not pressed, clear the previous selections:

if (!CtrlPressed)
{
    List<treeviewitem /> selectedTreeViewItemList = new List<treeviewitem />();
    foreach (TreeViewItem treeViewItem1 in selectedItems.Keys)
    {
        selectedTreeViewItemList.Add(treeViewItem1);
    }

    foreach (TreeViewItem treeViewItem1 in selectedTreeViewItemList)
    {
        Deselect(treeViewItem1);
    }
}

Then, flip flop the selection state of the item: if selected, make it unselected and vice versa:

ChangeSelectedState(treeViewItem);

We check whether LeftCtrl key is pressed or not by implementing the following property:

bool CtrlPressed
{
   get
   {
       return System.Windows.Input.Keyboard.IsKeyDown(Key.LeftCtrl);
   }
}

History

  • 23rd March, 2008: Initial post

License

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

Share

About the Author

Nick Polyak
Architect AWebPros
United States United States
I have 15 years of experience developing enterprise software, starting from C++ and Java on UNIX and moving towards C# on Windows platforms.
I am fascinated by the new .NET technologies especially WPF, Silverlight and LINQ.
Recently I decided to make a move and start my own contracting consulting and mentoring company AWebPros.
I can be contacted via my web site awebpros.com or through my blog at nickssoftwareblog.com

You may also be interested in...

Comments and Discussions

 
GeneralMy vote of 3 Pin
Chougule Vinay10-May-12 4:56
memberChougule Vinay10-May-12 4:56 
SuggestionSimpler and Improved Version Pin
kessbest13-Jul-11 6:04
memberkessbest13-Jul-11 6:04 
GeneralRe: Simpler and Improved Version Pin
Nick Polyak13-Jul-11 13:40
memberNick Polyak13-Jul-11 13:40 
GeneralRe: Simpler and Improved Version Pin
PSchegolevatykh28-Mar-12 23:15
memberPSchegolevatykh28-Mar-12 23:15 
GeneralMake MS notice Pin
Member 778244829-Mar-11 21:08
memberMember 778244829-Mar-11 21:08 
Generaldecent article Pin
CIDev6-Jan-11 8:22
memberCIDev6-Jan-11 8:22 
QuestionHow to bind the data from database to treeview Pin
Member 603819613-May-09 18:51
memberMember 603819613-May-09 18:51 
AnswerRe: How to bind the data from database to treeview Pin
Nick Polyak14-May-09 2:14
memberNick Polyak14-May-09 2:14 
I do not understand the question and how it is related to the article on multiselecting.

Can you be more specific?

Nick Polyak

GeneralA good starting point. but ... Pin
tabor2530-Apr-08 2:18
membertabor2530-Apr-08 2:18 
GeneralRe: A good starting point. but ... [modified] Pin
Nick Polyak30-Apr-08 2:48
memberNick Polyak30-Apr-08 2:48 
GeneralRe: A good starting point. but ... Pin
tabor251-May-08 6:16
membertabor251-May-08 6:16 
GeneralRe: A good starting point. but ... Pin
Nick Polyak1-May-08 15:12
memberNick Polyak1-May-08 15:12 
GeneralRe: A good starting point. but ... Pin
otbld_simon9-Aug-09 21:21
memberotbld_simon9-Aug-09 21:21 
GeneralRe: A good starting point. but ... Pin
Nick Polyak10-Aug-09 5:09
memberNick Polyak10-Aug-09 5:09 
AnswerRe: A good starting point. but ... Pin
jan.mudrak@gmail.com6-Dec-11 1:02
memberjan.mudrak@gmail.com6-Dec-11 1:02 
GeneralRe: A good starting point. but ... Pin
Nick Polyak6-Dec-11 15:22
memberNick Polyak6-Dec-11 15:22 

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

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

| Advertise | Privacy | Terms of Use | Mobile
Web02 | 2.8.150731.1 | Last Updated 23 Mar 2008
Article Copyright 2008 by Nick Polyak
Everything else Copyright © CodeProject, 1999-2015
Layout: fixed | fluid