c# - How can I programmatically scroll a WPF listview?

Question

Is it possible to programmatically scroll a WPF listview? I know winforms doesn't do it, right?

I am talking about say scrolling 50 units up or down, etc. Not scrolling an entire item height at once.

Answer 1

Yes, you'll have to grab the ScrollViwer from the ListView, or but once you have access to that, you can use the methods exposed by it or override the scrolling. You can also scroll by getting the main content area and using it's implementation of the IScrollInfo interface.

Here's a little helper to get the ScrollViwer component of something like a ListBox, ListView, etc.

public static DependencyObject GetScrollViewer(DependencyObject o)
{
    // Return the DependencyObject if it is a ScrollViewer
    if (o is ScrollViewer)
    { return o; }

    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(o); i++)
    {
        var child = VisualTreeHelper.GetChild(o, i);

        var result = GetScrollViewer(child);
        if (result == null)
        {
            continue;
        }
        else
        {
            return result;
        }
    }
    return null;
}

And then you can just use .LineUp() and .LineDown() like this:

private void OnScrollUp(object sender, RoutedEventArgs e)
{
    var scrollViwer = GetScrollViewer(uiListView) as ScrollViewer;

    if (scrollViwer != null)
    {
       // Logical Scrolling by Item
       // scrollViwer.LineUp();
       // Physical Scrolling by Offset
       scrollViwer.ScrollToVerticalOffset(scrollViwer.VerticalOffset + 3);
    }
}

private void OnScrollDown(object sender, RoutedEventArgs e)
{
    var scrollViwer = GetScrollViewer(uiListView) as ScrollViewer;

    if (scrollViwer != null)
    {
        // Logical Scrolling by Item
        // scrollViwer.LineDown();
        // Physical Scrolling by Offset
        scrollViwer.ScrollToVerticalOffset(scrollViwer.VerticalOffset + 3);
    }
}


<DockPanel>
    <Button DockPanel.Dock="Top"
            Content="Scroll Up"
            Click="OnScrollUp" />
    <Button DockPanel.Dock="Bottom"
            Content="Scroll Down"
            Click="OnScrollDown" />
    <ListView x:Name="uiListView">
        <!-- Content -->
    </ListView>
</DockPanel>

The Logical scrolling exposed by LineUp and LineDown do still scroll by item, if you want to scroll by a set amount you should use the ScrollToHorizontal/VerticalOffset that I've used above. If you want some more complex scrolling too, then take a look at the answer I've provided in this other question.