Fix TitleBar Sample mucking up App's TitleBar

components/TitleBar/src/TitleBar.UWP.cs

@@ -30,16 +30,22 @@ private void SetUWPTitleBar()
 
             PART_DragRegion = GetTemplateChild(nameof(PART_DragRegion)) as Grid;
             Window.Current.SetTitleBar(PART_DragRegion);
+
+            _isAutoConfigCompleted = true;
         }
     }
 
     private void ResetUWPTitleBar()
     {
-        CoreApplication.GetCurrentView().TitleBar.ExtendViewIntoTitleBar = false;
-        Window.Current.Activated -= this.Current_Activated;
-        SizeChanged -= this.TitleBar_SizeChanged;
-        CoreApplication.GetCurrentView().TitleBar.LayoutMetricsChanged -= this.TitleBar_LayoutMetricsChanged;
-        Window.Current.SetTitleBar(null);
+        // Only reset if we were the ones who configured
+        if (_isAutoConfigCompleted)
+        {
+            CoreApplication.GetCurrentView().TitleBar.ExtendViewIntoTitleBar = false;
+            Window.Current.Activated -= this.Current_Activated;
+            SizeChanged -= this.TitleBar_SizeChanged;
+            CoreApplication.GetCurrentView().TitleBar.LayoutMetricsChanged -= this.TitleBar_LayoutMetricsChanged;
+            Window.Current.SetTitleBar(null);
+        }
     }
 
     private void Current_Activated(object sender, Windows.UI.Core.WindowActivatedEventArgs e)

components/TitleBar/src/TitleBar.WASDK.cs

@@ -76,6 +76,8 @@ private void SetWASDKTitleBar()
             // Recalculate the drag region for the custom title bar 
             // if you explicitly defined new draggable areas.
             SetDragRegionForCustomTitleBar();
+
+            _isAutoConfigCompleted = true;
         }
     }
 
@@ -108,11 +110,15 @@ private void ResetWASDKTitleBar()
             // TO DO: Throw exception that window has not been set? 
         }
 
-        Window.AppWindow.TitleBar.ExtendsContentIntoTitleBar = false;
-        this.Window.SizeChanged -= Window_SizeChanged;
-        this.Window.Activated -= Window_Activated;
-        SizeChanged -= this.TitleBar_SizeChanged;
-        Window.AppWindow.TitleBar.ResetToDefault();
+        // Only reset if we were the ones who configured
+        if (_isAutoConfigCompleted)
+        {
+            Window.AppWindow.TitleBar.ExtendsContentIntoTitleBar = false;
+            this.Window.SizeChanged -= Window_SizeChanged;
+            this.Window.Activated -= Window_Activated;
+            SizeChanged -= this.TitleBar_SizeChanged;
+            Window.AppWindow.TitleBar.ResetToDefault();
+        }
     }
 
     private void Window_Activated(object sender, WindowActivatedEventArgs args)

components/TitleBar/src/TitleBar.cs

@@ -67,6 +67,10 @@ public partial class TitleBar : Control
     ColumnDefinition? PART_RightPaddingColumn;
     StackPanel? PART_ButtonHolder;
 
+    // Internal tracking (if AutoConfigureCustomTitleBar is on) if we've actually setup the TitleBar yet or not
+    // We only want to reset TitleBar configuration in app, if we're the TitleBar instance that's managing that state.
+    private bool _isAutoConfigCompleted = false;
+
     public TitleBar()
     {
         this.DefaultStyleKey = typeof(TitleBar);