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Код

public class ItemCarusel : Canvas
{

       static ItemCarusel ()
        {
            FrameworkPropertyMetadata offsetData =
                new FrameworkPropertyMetadata(0d, FrameworkPropertyMetadataOptions.AffectsArrange, new PropertyChangedCallback(OnOffsetYChanged));
            OffsetYProperty = DependencyProperty.Register("OffsetY", typeof(Double), typeof(ItemCarusel), offsetData , null);
        }
        private static void OnOffsetYChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            ItemCarusel container = (ItemCarusel )d;
            double value = (double)e.NewValue;
            container.OffsetY = value;
            
        }
        public Double OffsetY
        {
            set
            {
                this.SetValue(OffsetYProperty, value);
            }
            get { return (Double)this.GetValue(OffsetYProperty); }
        }
        public static readonly DependencyProperty OffsetYProperty;

protected override Size MeasureOverride(Size constraint)
        {
            double h = 0;
            foreach (Object childObject in Children)
            {
                Item gItem = childObject as Item;
                if (!gtem.IsMeasureValid)
                    gItem.Measure(new Size(constraint.Width, Double.PositiveInfinity));
                h += gItem.DesiredSize.Height;
            }
            this.Clip = new RectangleGeometry(new Rect(new Point(0, 0), constraint));
            new Size(constraint.Width, h);
        }
       
        protected override Size ArrangeOverride(Size arrangeSize)
        {
            double y = 0; 
            double realY = y - OffsetY; 
            double minY = 0;

            for (int i = 0; i < Children.Count; i++)
            {
                Item gItem = Children[i] as Item;
                MyData data = gItem.DataContext as MyData;
                
                if (realY + gItem.DesiredSize.Height <= 0 || realY >= C_HEIGHT)
                    data.Rendered = false;
                else
                    data.Rendered = true;
                
                gItem.Arrange(new Rect(0, realY, gItem.DesiredSize.Width, gItem.DesiredSize.Height));
               
               
                y += gItem.DesiredSize.Height;
                realY = y - OffsetY;
                if (i == 0)
                    minY = realY;
                                
            }
            
            if (realY >= 0 && realY <= this.RenderSize.Height)
            {
                //Если в отрендереном контейнере имеется свободное место для айтемов, то дорисовываем их 
                for (int i = 0; i < Children.Count; i++)
                {
                    Item gameItem = Children[i] as Item;
                    MyData data = gItem.DataContext as MyData;
                    if (data.Rendered || realY > this.RenderSize.Height)
                        break;
                    gItem.Arrange(new Rect(0, realY, gItem.DesiredSize.Width, gItem.DesiredSize.Height));
                    y += gItem.DesiredSize.Height;
                    realY = y - OffsetY;
               }
            }
            return arrangeSize;
        }
}