Fix Expander expand icon position bug

src/AtomUI.Controls/Expander/Expander.cs

@@ -278,6 +278,14 @@ public class Expander : AvaloniaExpander,
             }
         }
 
+        if (this.IsAttachedToVisualTree())
+        {
+            if (change.Property == IsBorderlessProperty)
+            {
+                SetupEffectiveBorderThickness();
+            }
+        }
+
         if (change.Property == ExpandIconProperty)
         {
             if (change.OldValue is Icon oldIcon)
@@ -290,16 +298,7 @@ public class Expander : AvaloniaExpander,
                 newIcon.SetTemplatedParent(this);
             }
         }
-
-        if (this.IsAttachedToVisualTree())
-        {
-            if (change.Property == IsBorderlessProperty)
-            {
-                SetupEffectiveBorderThickness();
-            }
-        }
-
-        if (change.Property == IsExpandedProperty)
+        else if (change.Property == IsExpandedProperty)
         {
             HandleExpandedChanged();
         }
@@ -310,6 +309,18 @@ public class Expander : AvaloniaExpander,
         {
             SetupExpanderBorderThickness();
         }
+        else if (change.Property == AddOnContentProperty)
+        {
+            if (change.OldValue is Control oldControl)
+            {
+                oldControl.SetTemplatedParent(null);
+            }
+
+            if (change.NewValue is Control newControl)
+            {
+                newControl.SetTemplatedParent(this);
+            }
+        }
     }
 
     private void SetupDefaultIcon()

src/AtomUI.Controls/TabControl/TabStrip/BaseTabStripItemTheme.cs

@@ -1,6 +1,5 @@
 using AtomUI.IconPkg;
 using AtomUI.Theme;
-using AtomUI.Theme.Data;
 using AtomUI.Theme.Styling;
 using Avalonia;
 using Avalonia.Controls;

src/AtomUI.Controls/TabControl/TabStrip/CardTabStrip.cs

@@ -3,7 +3,6 @@ using AtomUI.Data;
 using AtomUI.Theme;
 using AtomUI.Theme.Data;
 using AtomUI.Theme.Styling;
-using AtomUI.Utils;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Presenters;

src/AtomUI.Controls/TabControl/TabStrip/CardTabStripTheme.cs

@@ -1,7 +1,4 @@
-using AtomUI.IconPkg;
-using AtomUI.IconPkg.AntDesign;
-using AtomUI.Theme;
-using AtomUI.Theme.Data;
+using AtomUI.IconPkg.AntDesign;
 using AtomUI.Theme.Styling;
 using Avalonia;
 using Avalonia.Controls;

src/AtomUI.Controls/TabControl/TabStrip/TabStripTheme.cs

@@ -1,7 +1,4 @@
-using AtomUI.Theme;
-using AtomUI.Theme.Data;
-using AtomUI.Theme.Styling;
-using AtomUI.Utils;
+using AtomUI.Theme.Styling;
 using Avalonia.Controls;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Templates;