From e4162eeeb6919d39bef0e3af3b81ff747b857621 Mon Sep 17 00:00:00 2001
From: Andrew KeepCoding <andrewkeepcoding@gmail.com>
Date: Wed, 17 Sep 2025 17:52:29 +0900
Subject: [PATCH 1/3] Fix titlebar gap under caption buttons

---
 WinUIGallery/MainWindow.xaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/WinUIGallery/MainWindow.xaml b/WinUIGallery/MainWindow.xaml
index 6a7d12f06..da5768639 100644
--- a/WinUIGallery/MainWindow.xaml
+++ b/WinUIGallery/MainWindow.xaml
@@ -13,6 +13,9 @@
         <MicaBackdrop />
     </Window.SystemBackdrop>
     <Grid x:Name="RootGrid" Loaded="RootGrid_Loaded">
+        <Grid.Resources>
+            <x:Double x:Key="TitleBarExpandedHeight">46</x:Double>
+        </Grid.Resources>
         <Grid.RowDefinitions>
             <RowDefinition Height="Auto" />
             <RowDefinition Height="*" />

From b148634fb16e294499bd4f46a0fa6991527bdb8b Mon Sep 17 00:00:00 2001
From: Andrew KeepCoding <andrewkeepcoding@gmail.com>
Date: Fri, 19 Sep 2025 11:03:52 +0900
Subject: [PATCH 2/3] Revert "Fix titlebar gap under caption buttons"

This reverts commit e4162eeeb6919d39bef0e3af3b81ff747b857621.
---
 WinUIGallery/MainWindow.xaml | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/WinUIGallery/MainWindow.xaml b/WinUIGallery/MainWindow.xaml
index da5768639..6a7d12f06 100644
--- a/WinUIGallery/MainWindow.xaml
+++ b/WinUIGallery/MainWindow.xaml
@@ -13,9 +13,6 @@
         <MicaBackdrop />
     </Window.SystemBackdrop>
     <Grid x:Name="RootGrid" Loaded="RootGrid_Loaded">
-        <Grid.Resources>
-            <x:Double x:Key="TitleBarExpandedHeight">46</x:Double>
-        </Grid.Resources>
         <Grid.RowDefinitions>
             <RowDefinition Height="Auto" />
             <RowDefinition Height="*" />

From 0f16190426799313164b95c11498caefcc4f628d Mon Sep 17 00:00:00 2001
From: Andrew KeepCoding <andrewkeepcoding@gmail.com>
Date: Fri, 19 Sep 2025 11:49:26 +0900
Subject: [PATCH 3/3] Adjust NavigationView margin based on window state

Added `WindowPresenter` and `CurrentWindowState` properties to track and manage the window's presentation state. Updated the `MainWindow` constructor to initialize these properties and adjust the `NavigationView` margin dynamically. Introduced the `AdjustNavigationViewMargin` method to handle margin adjustments when the window state changes, ensuring proper alignment of the `NavigationView` with the caption buttons.
---
 WinUIGallery/MainWindow.xaml.cs | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/WinUIGallery/MainWindow.xaml.cs b/WinUIGallery/MainWindow.xaml.cs
index 0dda5d96e..95ba6e764 100644
--- a/WinUIGallery/MainWindow.xaml.cs
+++ b/WinUIGallery/MainWindow.xaml.cs
@@ -32,12 +32,35 @@ public NavigationView NavigationView
 
     public Action NavigationViewLoaded { get; set; }
 
+    private OverlappedPresenter WindowPresenter { get; init; }
+
+    private OverlappedPresenterState CurrentWindowState { get; set; }
+
     public MainWindow()
     {
         this.InitializeComponent();
         SetWindowProperties();
         RootGrid.ActualThemeChanged += (_, _) => TitleBarHelper.ApplySystemThemeToCaptionButtons(this, RootGrid.ActualTheme);
         dispatcherQueue = Microsoft.UI.Dispatching.DispatcherQueue.GetForCurrentThread();
+
+        WindowPresenter = AppWindow.Presenter as OverlappedPresenter;
+        CurrentWindowState = WindowPresenter.State;
+        AdjustNavigationViewMargin(force: true);
+        AppWindow.Changed += (_, _) => AdjustNavigationViewMargin();
+    }
+
+    // Adjusts the NavigationView margin based on the window state to fix the gap between the caption buttons and the NavigationView.
+    private void AdjustNavigationViewMargin(bool? force = null)
+    {
+        if (WindowPresenter.State == CurrentWindowState && force is not true)
+        {
+            return;
+        }
+
+        NavigationView.Margin = WindowPresenter.State == OverlappedPresenterState.Maximized
+            ? new Thickness(0, -1, 0, 0)
+            : new Thickness(0, -2, 0, 0);
+        CurrentWindowState = WindowPresenter.State;
     }
 
     private void RootGrid_Loaded(object sender, RoutedEventArgs e)