优化更新代码，添加界面功能并整合

WPFluent/Controls/VirtualizingPanel/VirtualizingItemsControl.cs

@@ -0,0 +1,51 @@
+
+
+
+/* Based on VirtualizingWrapPanel created by S. Bäumlisberger licensed under MIT license.
+   https://github.com/sbaeumlisberger/VirtualizingWrapPanel
+   Copyright (C) S. Bäumlisberger
+   All Rights Reserved. */
+
+using System.Windows.Controls;
+
+// ReSharper disable once CheckNamespace
+namespace WPFluent.Controls;
+
+/// <summary>
+/// Virtualized <see cref="ItemsControl"/>. <para>Based on <see
+/// href="https://github.com/sbaeumlisberger/VirtualizingWrapPanel"/>.</para>
+/// </summary>
+public class VirtualizingItemsControl : ItemsControl
+{
+    /// <summary>
+    /// Identifies the <see cref="CacheLengthUnit"/> dependency property.
+    /// </summary>
+    public static readonly DependencyProperty CacheLengthUnitProperty = DependencyProperty.Register(
+        nameof(CacheLengthUnit),
+        typeof(VirtualizationCacheLengthUnit),
+        typeof(VirtualizingItemsControl),
+        new FrameworkPropertyMetadata(VirtualizationCacheLengthUnit.Page));
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="VirtualizingItemsControl"/> class.
+    /// </summary>
+    public VirtualizingItemsControl()
+    {
+        VirtualizingPanel.SetCacheLengthUnit(this, CacheLengthUnit);
+        VirtualizingPanel.SetCacheLength(this, new VirtualizationCacheLength(1));
+        VirtualizingPanel.SetIsVirtualizingWhenGrouping(this, true);
+    }
+
+    /// <summary>
+    /// Gets or sets the cache length unit.
+    /// </summary>
+    public VirtualizationCacheLengthUnit CacheLengthUnit
+    {
+        get => VirtualizingPanel.GetCacheLengthUnit(this);
+        set
+        {
+            SetValue(CacheLengthUnitProperty, value);
+            VirtualizingPanel.SetCacheLengthUnit(this, value);
+        }
+    }
+}