Fluffy Comments - Answer Overflow

Fluffy

•Created by Fluffy on 1/9/2024 in #help

Scrollviewer not staying at the bottom when new insert. MVVM .NET Frameworks 4.5 XAML

The answer to my own question

private void scrollviewer_Messages_ScrollChanged(object sender, ScrollChangedEventArgs e)
{
    ScrollViewer scrollViewer = sender as ScrollViewer;
    if (e.ExtentHeightChange == 0)
    {   // Content unchanged : user scroll event
        if (scrollViewer.VerticalOffset == scrollViewer.ScrollableHeight)
        {   // Scroll bar is in bottom
            // Set auto-scroll mode
            AutoScroll = true;
        }
        else
        {   // Scroll bar isn't in bottom
            // Unset auto-scroll mode
            AutoScroll = false;
        }
    }

    // Content scroll event : auto-scroll eventually
    if (AutoScroll && e.ExtentHeightChange != 0)
    {   // Content changed and auto-scroll mode set
        // Autoscroll
        scrollViewer.ScrollToVerticalOffset(scrollViewer.ExtentHeight);
    }
}

private void scrollviewer_Messages_ScrollChanged(object sender, ScrollChangedEventArgs e)
{
    ScrollViewer scrollViewer = sender as ScrollViewer;
    if (e.ExtentHeightChange == 0)
    {   // Content unchanged : user scroll event
        if (scrollViewer.VerticalOffset == scrollViewer.ScrollableHeight)
        {   // Scroll bar is in bottom
            // Set auto-scroll mode
            AutoScroll = true;
        }
        else
        {   // Scroll bar isn't in bottom
            // Unset auto-scroll mode
            AutoScroll = false;
        }
    }

    // Content scroll event : auto-scroll eventually
    if (AutoScroll && e.ExtentHeightChange != 0)
    {   // Content changed and auto-scroll mode set
        // Autoscroll
        scrollViewer.ScrollToVerticalOffset(scrollViewer.ExtentHeight);
    }
}

added this event handler that checks if scroll bar is at the bottom, if it is it enables auto scroll is not it stays

 <ScrollViewer x:Name="MessageScroller" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto" ScrollChanged="scrollviewer_Messages_ScrollChanged">
     <ItemsPresenter />
 </ScrollViewer>

 <ScrollViewer x:Name="MessageScroller" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto" ScrollChanged="scrollviewer_Messages_ScrollChanged">
     <ItemsPresenter />
 </ScrollViewer>

Added the ScrollChanged which fires the event

4 replies

Gaming

Programming