Selecting first item in listbox

Question

A listbox works as an auto-complete within a richtextbox I am populating it with items from a collection. I need it to auto select first item every time listbox populates.

How do I do this?

Thank you

foreach (var ks in ksd.FindValues(comparable))
      {
          lb.Items.Add(ks.Value);
      }

      if (lb.HasItems)
      {
          lb.Visibility = System.Windows.Visibility.Visible;
          lb.SelectedIndex = 0; //Suggested solution, still doesn't work 
      }
      else
      {
          lb.Visibility = System.Windows.Visibility.Collapsed;
      }

Peter PAD · Accepted Answer · 2011-11-22T04:13:18.977

36

You can put SelectedIndex to 0 in XAML for the first time loading

<ListBox SelectedIndex="0" />

In code-behind, you can do this after loading items list

        if (this.lst.Items.Count > 0)
            this.lst.SelectedIndex = 0;

edited Nov 22 '11 at 04:13

answered Nov 22 '11 at 04:02

Peter PAD

2,252
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this is what I have and its not working – gumenimeda Nov 22 '11 at 04:05
How to you populate your list? I mean do you use binding? – Peter PAD Nov 22 '11 at 04:10
No. I am populating it with listbox.Items.Add() Thanks for help – gumenimeda Nov 22 '11 at 04:15
1

The first selection item have index 0. So you can do like my post. (after editing) – Peter PAD Nov 22 '11 at 04:18
Still not working something might be wrong with my code. I'll go through and post it if I don't figure it out. Thanks – gumenimeda Nov 22 '11 at 04:29
For a ListView this would only select the first item. If you want focus as well then you might have to do something like [this](http://stackoverflow.com/a/11747701/1201038). – The Lonely Coder Oct 22 '14 at 13:30

score 14 · Answer 2 · edited May 11 '15 at 16:17

14

If you're using MVVM then you can also try another solution:

Add property called SelectedValue to the ViewModel;
After loading (or adding) values to the List that you bind to the ListBox set SelectedValue withvaluesList.FirstOrDefault();
On the XAML bind the SelectedItem property of the ListBox to SelectedValue (from ViewModel) and set binding Mode="TwoWay"

edited May 11 '15 at 16:17

D.Rosado

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answered Nov 22 '11 at 09:01

Anatolii Gabuza

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I know it's been a couple years, but it definitely should be the accepted answer! :) – Johnny Prescott May 21 '17 at 04:10

score 2 · Answer 3 · edited Jan 29 '13 at 20:02

2

This should work:

listBox1.SetSelected(0,true);

edited Jan 29 '13 at 20:02

kiritsuku

52,967
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answered Jan 29 '13 at 19:40

هادی کشاورز Hadi Keshavarz

73
5

score -1 · Answer 4 · answered Feb 29 '12 at 10:56

You don't need anything just the data you use. You shouldn't be interested how the Control looks like. (You don't want to be coupled with that control)

<ListBox ItemsSource="{Binding MyItems}" SelectedItem="{Binding MyItem}" />

could be:

<SexyWoman Legs="{Binding MyItems}" Ass="{Binding MyItem}" />

and it will work as well.

The ListBox has this class as a DataContext:

class DummyClass : INotifyPropertyChanged
{

    private MyItem _myItem;
    public MyItem MyItem
    {
        get { return _myItem; }
        set { _myItem = value; NotifyPropertyChanged("MyItem"); }
    }

    private IEnumerable<MyItem> _myItems;
    public IEnumerable<MyItem> MyItems
    {
        get { return _myItems; }        
    }

    public void FillWithItems()
    {
        /* Some logic */
        _myItems = ...

        NotifyPropertyChanged("MyItems");

        /* This automatically selects the first element */
        MyItem = _myItems.FirstOrDefault();
    }

    #region INotifyPropertyChanged Members
    public event PropertyChangedEventHandler PropertyChanged;

    private void NotifyPropertyChanged(string value)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(value));
        }
    }
    #endregion
}

-1: Sorry, I totally don't understand how any of your examples actually answer the question on hand. I think it would be helpful if you could just put in the specific code block, rather than the entire VM? — code4life, Apr 09 '14 at 17:32

Selecting first item in listbox

4 Answers4