Create EventToCommand.ScrollView.Scrolled.cs

NuGet/RapidXaml.MAUI/EventToCommand/EventToCommand.ScrollView.Scrolled.cs

@@ -0,0 +1,66 @@
+using System.Windows.Input;
+
+namespace RapidXaml;
+
+public partial class EventToCommand : BindableObject
+{
+	public static ICommand GetScrolled(BindableObject obj)
+		=> (ICommand)obj.GetValue(ScrolledProperty);
+
+	public static void SetScrolled(BindableObject obj, ICommand value)
+		=> obj.SetValue(ScrolledProperty, value);
+
+	public static readonly BindableProperty ScrolledProperty =
+		BindableProperty.CreateAttached("Scrolled", typeof(ICommand), typeof(EventToCommand), defaultValue: null, propertyChanged: OnScrolledChanged);
+
+	private static void OnScrolledChanged(BindableObject bindable, object oldValue, object newValue)
+	{
+		if (bindable is ScrollView sv)
+		{
+			if (oldValue is ICommand oldCmd)
+			{
+				for (int i = sv.Behaviors.Count; i >= 0; i--)
+				{
+					if (sv.Behaviors[i] is EventToCommandScrolledBehavior oldBehavior && oldBehavior.CommandToInvoke == oldCmd)
+					{
+						sv.Behaviors.Remove(oldBehavior);
+						break;
+					}
+				}
+			}
+
+			if (newValue is ICommand newCmd)
+			{
+				sv.Behaviors.Add(new EventToCommandScrolledBehavior { CommandToInvoke = newCmd });
+			}
+		}
+	}
+
+	internal partial class EventToCommandScrolledBehavior : Behavior<ScrollView>
+	{
+		public ICommand? CommandToInvoke { get; set; }
+
+		protected override void OnAttachedTo(ScrollView sv)
+		{
+			sv.Scrolled += OnScrollViewerScrolled;
+			base.OnAttachedTo(sv);
+		}
+
+		protected override void OnDetachingFrom(ScrollView sv)
+		{
+			sv.Scrolled -= OnScrollViewerScrolled;
+			base.OnDetachingFrom(sv);
+		}
+
+		private void OnScrollViewerScrolled(object? sender, EventArgs e)
+		{
+			if (this.CommandToInvoke != null)
+			{
+				if (this.CommandToInvoke.CanExecute(null))
+				{
+					this.CommandToInvoke.Execute(null);
+				}
+			}
+		}
+	}
+}