优化更新代码，添加界面功能并整合

WPFluent/Controls/NumberBox/NumberBoxSpinButtonPlacementMode.cs

@@ -0,0 +1,30 @@
+
+
+
+// This Source Code is partially based on the source code provided by the .NET Foundation.
+
+// ReSharper disable once CheckNamespace
+namespace WPFluent.Controls;
+
+/// <summary>
+/// Defines values that specify how the spin buttons used to increment or decrement the <see cref="NumberBox.Value"/>
+/// are displayed.
+/// </summary>
+public enum NumberBoxSpinButtonPlacementMode
+{
+    /// <summary>
+    /// The spin buttons are not displayed.
+    /// </summary>
+    Hidden,
+
+    /// <summary>
+    /// The spin buttons have two visual states, depending on focus. By default, the spin buttons are displayed in a
+    /// compact, vertical orientation. When the Numberbox gets focus, the spin buttons expand.
+    /// </summary>
+    Compact,
+
+    /// <summary>
+    /// The spin buttons are displayed in an expanded, horizontal orientation.
+    /// </summary>
+    Inline,
+}