CODEWITHSUNDEEP
c#wpflistview
user2039445
user2039445

Reputation: 273

How to use ScrollIntoView for ListView in xaml

I have a ControlTemplate to show Items in ListView. ListView is having 500+ items. I am preserving the state and getting selected item from XML and sending it to listview to select it by default for next navigation to the screen.

My problem is How can I set selected item (which may be present in last i.e. out of view) by xaml. ViewModel doesn't know about any UI control, so I cant apply ScrollIntoView method in ViewModel.

Can I use any Setter or Style to do this?

Please suggest.

Upvotes: 0

Views: 1476

Answers (1)

mamuesstack
mamuesstack

Reputation: 1251

I've recently done this with a DataGrid. The trick is to attach a custom Behavior to your View. Like that.

<ListView ... >
    <iy:Interaction.Behaviors>
        <ext:ScrollIntoViewBehavior />
    </iy:Interaction.Behaviors>
    ...
</ListView>

And the assocciated class:

public class ScrollIntoViewBehavior : Behavior<ListView>
{
    protected override void OnAttached()
    {
        base.OnAttached();
        this.AssociatedObject.SelectionChanged += new SelectionChangedEventHandler(AssociatedObject_SelectionChanged);
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();
        this.AssociatedObject.SelectionChanged -= new SelectionChangedEventHandler(AssociatedObject_SelectionChanged);
    }

    private void AssociatedObject_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        if (sender is ListView)
        {
            ListView grid = (sender as ListView);
            if (grid.SelectedItem != null)
            {
                grid.Dispatcher.BeginInvoke(() =>
                {
                    grid.UpdateLayout();
                    grid.ScrollIntoView(grid.SelectedItem);
                });
            }
        }
    }
}

Some things to be aware of:

Upvotes: 1

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