CODEWITHSUNDEEP
c#wpflistboxselection
Tim Pohlmann
Tim Pohlmann

Reputation: 4430

Deselect on single click in a ListBox with Extended SelectionMode

I have a ListBox with SelectionMode="Extended". You can only deselect the last item by holding down ctrl while clicking on it. I would like to be able to deselect the item by just clicking on it while not changing the behavior of the Extended selection mode other than that.

I only found one question about this topic and it actually has a different goal (being able to deselect all items by clicking outside of the ListBox).

Upvotes: 2

Views: 1367

Answers (1)

mm8
mm8

Reputation: 169240

If I understand your requirement correctly you could handle the PreviewMouseLeftButtonDown event for the ListBoxItem container and de-select it if it's already selected:

<ListBox SelectionMode="Extended">
    <ListBox.ItemContainerStyle>
        <Style TargetType="ListBoxItem">
            <EventSetter Event="PreviewMouseLeftButtonDown" Handler="OnMouseLeftButtonDown"/>
        </Style>
    </ListBox.ItemContainerStyle>
    <ListBoxItem>1</ListBoxItem>
    <ListBoxItem>2</ListBoxItem>
    <ListBoxItem>3</ListBoxItem>
</ListBox>

private void OnMouseLeftButtonDown(object sender, MouseEventArgs e)
{
    ListBoxItem lbi = sender as ListBoxItem;
    if (lbi != null)
    {
        if (lbi.IsSelected)
        {
            lbi.IsSelected = false;
            e.Handled = true;
        }
    }
}

This should allow you to be able to de-select an item without using the CTRL key.

Upvotes: 3

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