Scrolled event implemented (#8197)

diff --git a/Xamarin.Forms.Platform.WPF/Renderers/ListViewRenderer.cs b/Xamarin.Forms.Platform.WPF/Renderers/ListViewRenderer.cs
index 658429b..d31ee95 100644 (file)
--- a/Xamarin.Forms.Platform.WPF/Renderers/ListViewRenderer.cs
+++ b/Xamarin.Forms.Platform.WPF/Renderers/ListViewRenderer.cs
@@ -32,6 +32,7 @@ namespace Xamarin.Forms.Platform.WPF
                ITemplatedItemsView<Cell> TemplatedItemsView => Element;
                WpfScrollBarVisibility? _defaultHorizontalScrollVisibility;
                WpfScrollBarVisibility? _defaultVerticalScrollVisibility;
+               ScrollViewer _scrollViewer;
 
                public override SizeRequest GetDesiredSize(double widthConstraint, double heightConstraint)
                {
@@ -50,6 +51,18 @@ namespace Xamarin.Forms.Platform.WPF
                                var templatedItems = ((ITemplatedItemsView<Cell>)e.OldElement).TemplatedItems;
                                templatedItems.CollectionChanged -= OnCollectionChanged;
                                templatedItems.GroupedCollectionChanged -= OnGroupedCollectionChanged;
+                               if (Control != null)
+                               {
+                                       Control.MouseUp -= OnNativeMouseUp;
+                                       Control.KeyUp -= OnNativeKeyUp;
+                                       Control.TouchUp -= OnNativeTouchUp;
+                                       Control.StylusUp -= OnNativeStylusUp;
+                                       Control.Loaded -= ControlOnLoaded;
+                               }
+                               if (_scrollViewer != null)
+                               {
+                                       _scrollViewer.ScrollChanged -= SendScrolled;
+                               }
                        }
 
                        if (e.NewElement != null)
@@ -74,6 +87,7 @@ namespace Xamarin.Forms.Platform.WPF
                                        Control.KeyUp += OnNativeKeyUp;
                                        Control.TouchUp += OnNativeTouchUp;
                                        Control.StylusUp += OnNativeStylusUp;
+                                       Control.Loaded += ControlOnLoaded;
                                }
 
                                // Suscribe element events
@@ -92,6 +106,22 @@ namespace Xamarin.Forms.Platform.WPF
 
                        base.OnElementChanged(e);
                }
+
+               void ControlOnLoaded(object sender, RoutedEventArgs e)
+               {
+                       _scrollViewer = Control.FindVisualChild<ScrollViewer>();
+                       if (_scrollViewer != null)
+                       {
+                               _scrollViewer.ScrollChanged += SendScrolled;
+                       }
+               }
+
+               void SendScrolled(object sender, ScrollChangedEventArgs e)
+               {
+                       var args = new ScrolledEventArgs(0, _scrollViewer.VerticalOffset);
+                       Element?.SendScrolled(args);
+               }
+
                void OnElementScrollToRequested(object sender, ScrollToRequestedEventArgs e)
                {
                        var scrollArgs = (ITemplatedItemsListScrollToRequestedEventArgs)e;
@@ -211,6 +241,11 @@ namespace Xamarin.Forms.Platform.WPF
                                        Control.KeyUp -= OnNativeKeyUp;
                                        Control.TouchUp -= OnNativeTouchUp;
                                        Control.StylusUp -= OnNativeStylusUp;
+                                       Control.Loaded -= ControlOnLoaded;
+                               }
+                               if (_scrollViewer != null)
+                               {
+                                       _scrollViewer.ScrollChanged -= SendScrolled;
                                }
 
                                if (Element != null)