From 8b345fe8edec7ea747e43154a2639b8cbdb20032 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Sun, 3 Nov 2024 20:08:13 -0800
Subject: [PATCH 01/18] Disabling ToolTip visual styles to make it dark enough
 in Dark mode

---
 .../System/Windows/Forms/ToolTip/ToolTip.cs   | 19 +++++++-----
 .../System/Windows/Forms/ToolTipTests.cs      | 30 +++++++++++++++++++
 2 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
index 6fad5f45a92..f99656f89aa 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
@@ -718,6 +718,13 @@ private unsafe void CreateHandle()
             {
                 PInvoke.SetWindowTheme(HWND, string.Empty, string.Empty);
             }
+
+#pragma warning disable WFO5001
+            if (Application.IsDarkModeEnabled)
+            {
+                PInvoke.SetWindowTheme(HWND, string.Empty, string.Empty);
+            }
+#pragma warning restore WFO5001
         }
 
         // If in OwnerDraw mode, we don't want the default border.
@@ -770,15 +777,11 @@ private unsafe void CreateHandle()
         // Set active status.
         PInvokeCore.SendMessage(this, PInvoke.TTM_ACTIVATE, (WPARAM)(BOOL)_active);
 
-        if (BackColor != SystemColors.Info)
-        {
-            PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPBKCOLOR, (WPARAM)BackColor);
-        }
+        // Set background color.
+        PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPBKCOLOR, (WPARAM)_backColor);
 
-        if (ForeColor != SystemColors.InfoText)
-        {
-            PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPTEXTCOLOR, (WPARAM)ForeColor);
-        }
+        // Set text color.
+        PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPTEXTCOLOR, (WPARAM)_foreColor);
 
         if (_toolTipIcon > 0 || !string.IsNullOrEmpty(_toolTipTitle))
         {
diff --git a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
index bbfd4f46ae7..16c0d18a062 100644
--- a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
+++ b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
@@ -782,6 +782,36 @@ public void ToolTip_ToString_Invoke_ReturnsExpected()
         Assert.Equal("System.Windows.Forms.ToolTip InitialDelay: 500, ShowAlways: False", toolTip.ToString());
     }
 
+#pragma warning disable WFO5001
+    [WinFormsFact]
+    public void ToolTip_DarkMode_GetColors_ReturnsExpected()
+    {
+        if (SystemInformation.HighContrast)
+        {
+            // We don't run this test in HighContrast mode.
+            return;
+        }
+
+        SystemColorMode colorMode = Application.ColorMode;
+        Application.SetColorMode(SystemColorMode.Dark);
+
+        using SubToolTip toolTip = new();
+
+        Assert.NotEqual(IntPtr.Zero, toolTip.Handle); // A workaround to create the toolTip native window Handle
+
+        var backgroundColor = PInvokeCore.SendMessage(toolTip, PInvoke.TTM_GETTIPBKCOLOR);
+        Color backColor = ColorTranslator.FromWin32((int)backgroundColor);
+
+        var textColor = PInvokeCore.SendMessage(toolTip, PInvoke.TTM_GETTIPTEXTCOLOR);
+        Color foreColor = ColorTranslator.FromWin32((int)textColor);
+
+        Assert.Equal(SystemColors.Info.ToArgb(), backColor.ToArgb());
+        Assert.Equal(SystemColors.InfoText.ToArgb(), foreColor.ToArgb());
+
+        Application.SetColorMode(colorMode);
+    }
+#pragma warning restore WFO5001
+
     [WinFormsFact]
     public void ToolTip_SetToolTipToControl_Invokes_SetToolTip_OfControl()
     {

From f5a017b92090ba392fa18fd5ba280ba6df075282 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Tue, 5 Nov 2024 20:37:47 -0800
Subject: [PATCH 02/18] Feedback from code review

---
 .../System/Windows/Forms/ToolTip/ToolTip.cs   |  7 +--
 .../ApplicationColorModeScope.cs              | 44 +++++++++++++++++++
 .../System/Windows/Forms/ToolTipTests.cs      | 10 ++---
 3 files changed, 48 insertions(+), 13 deletions(-)
 create mode 100644 src/System.Windows.Forms/tests/TestUtilities/ApplicationColorModeScope.cs

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
index f99656f89aa..ced2f6b464b 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
@@ -714,13 +714,8 @@ private unsafe void CreateHandle()
 
             _window.CreateHandle(cp);
 
-            if (SystemInformation.HighContrast)
-            {
-                PInvoke.SetWindowTheme(HWND, string.Empty, string.Empty);
-            }
-
 #pragma warning disable WFO5001
-            if (Application.IsDarkModeEnabled)
+            if (SystemInformation.HighContrast || Application.IsDarkModeEnabled)
             {
                 PInvoke.SetWindowTheme(HWND, string.Empty, string.Empty);
             }
diff --git a/src/System.Windows.Forms/tests/TestUtilities/ApplicationColorModeScope.cs b/src/System.Windows.Forms/tests/TestUtilities/ApplicationColorModeScope.cs
new file mode 100644
index 00000000000..7bdd79a1d67
--- /dev/null
+++ b/src/System.Windows.Forms/tests/TestUtilities/ApplicationColorModeScope.cs
@@ -0,0 +1,44 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Windows.Forms;
+
+namespace System;
+
+#pragma warning disable WFO5001
+/// <summary>
+///  Scope for setting the default color mode (dark mode) for the application. Use in a <see langword="using"/> statement.
+/// </summary>
+public readonly ref struct ApplicationColorModeScope
+{
+    private readonly SystemColorMode _originalColorMode;
+
+    public ApplicationColorModeScope(SystemColorMode colorMode)
+    {
+        // Prevent multiple ApplicationColorModeScopes from running simultaneously.
+        // Using Monitor to allow recursion on the same thread.
+        Monitor.Enter(typeof(ApplicationColorModeScope));
+        _originalColorMode = Application.ColorMode;
+
+        if (_originalColorMode != colorMode)
+        {
+            Application.SetColorMode(colorMode);
+        }
+    }
+
+    public void Dispose()
+    {
+        try
+        {
+            if (Application.ColorMode != _originalColorMode)
+            {
+                Application.SetColorMode(_originalColorMode);
+            }
+        }
+        finally
+        {
+            Monitor.Exit(typeof(ApplicationColorModeScope));
+        }
+    }
+}
+#pragma warning restore WFO5001
diff --git a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
index 16c0d18a062..b1704d52b9a 100644
--- a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
+++ b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
@@ -782,7 +782,7 @@ public void ToolTip_ToString_Invoke_ReturnsExpected()
         Assert.Equal("System.Windows.Forms.ToolTip InitialDelay: 500, ShowAlways: False", toolTip.ToString());
     }
 
-#pragma warning disable WFO5001
+ #pragma warning disable WFO5001
     [WinFormsFact]
     public void ToolTip_DarkMode_GetColors_ReturnsExpected()
     {
@@ -792,12 +792,10 @@ public void ToolTip_DarkMode_GetColors_ReturnsExpected()
             return;
         }
 
-        SystemColorMode colorMode = Application.ColorMode;
-        Application.SetColorMode(SystemColorMode.Dark);
-
+        using ApplicationColorModeScope colorModeScope = new(colorMode: SystemColorMode.Dark);
         using SubToolTip toolTip = new();
 
-        Assert.NotEqual(IntPtr.Zero, toolTip.Handle); // A workaround to create the toolTip native window Handle
+        toolTip.Handle.Should().NotBe(IntPtr.Zero); // A workaround to create the toolTip native window Handle
 
         var backgroundColor = PInvokeCore.SendMessage(toolTip, PInvoke.TTM_GETTIPBKCOLOR);
         Color backColor = ColorTranslator.FromWin32((int)backgroundColor);
@@ -807,8 +805,6 @@ public void ToolTip_DarkMode_GetColors_ReturnsExpected()
 
         Assert.Equal(SystemColors.Info.ToArgb(), backColor.ToArgb());
         Assert.Equal(SystemColors.InfoText.ToArgb(), foreColor.ToArgb());
-
-        Application.SetColorMode(colorMode);
     }
 #pragma warning restore WFO5001
 

From e980d698d5a5767326f3605199e83b961bb095ef Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Tue, 5 Nov 2024 20:39:57 -0800
Subject: [PATCH 03/18] Fix spacing

---
 .../tests/UnitTests/System/Windows/Forms/ToolTipTests.cs        | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
index b1704d52b9a..91116bd9f7b 100644
--- a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
+++ b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
@@ -782,7 +782,7 @@ public void ToolTip_ToString_Invoke_ReturnsExpected()
         Assert.Equal("System.Windows.Forms.ToolTip InitialDelay: 500, ShowAlways: False", toolTip.ToString());
     }
 
- #pragma warning disable WFO5001
+#pragma warning disable WFO5001
     [WinFormsFact]
     public void ToolTip_DarkMode_GetColors_ReturnsExpected()
     {

From 6e1fd22091d936484dcce2f1bfca6fc7de6d8664 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Tue, 5 Nov 2024 21:17:46 -0800
Subject: [PATCH 04/18] More fluent assertions

---
 .../tests/UnitTests/System/Windows/Forms/ToolTipTests.cs      | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
index 91116bd9f7b..2be455f84c2 100644
--- a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
+++ b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
@@ -803,8 +803,8 @@ public void ToolTip_DarkMode_GetColors_ReturnsExpected()
         var textColor = PInvokeCore.SendMessage(toolTip, PInvoke.TTM_GETTIPTEXTCOLOR);
         Color foreColor = ColorTranslator.FromWin32((int)textColor);
 
-        Assert.Equal(SystemColors.Info.ToArgb(), backColor.ToArgb());
-        Assert.Equal(SystemColors.InfoText.ToArgb(), foreColor.ToArgb());
+        backColor.ToArgb().Should().Be(SystemColors.Info.ToArgb());
+        foreColor.ToArgb().Should().Be(SystemColors.InfoText.ToArgb());
     }
 #pragma warning restore WFO5001
 

From ae2c320499f64e2ae84673ca8303256ccbacd89e Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Wed, 6 Nov 2024 19:22:07 -0800
Subject: [PATCH 05/18] ApplicationColorModeScope feedback from code review

---
 .../TestUtilities/ApplicationColorModeScope.cs     | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/src/System.Windows.Forms/tests/TestUtilities/ApplicationColorModeScope.cs b/src/System.Windows.Forms/tests/TestUtilities/ApplicationColorModeScope.cs
index 7bdd79a1d67..47b8eed443d 100644
--- a/src/System.Windows.Forms/tests/TestUtilities/ApplicationColorModeScope.cs
+++ b/src/System.Windows.Forms/tests/TestUtilities/ApplicationColorModeScope.cs
@@ -15,9 +15,6 @@ public readonly ref struct ApplicationColorModeScope
 
     public ApplicationColorModeScope(SystemColorMode colorMode)
     {
-        // Prevent multiple ApplicationColorModeScopes from running simultaneously.
-        // Using Monitor to allow recursion on the same thread.
-        Monitor.Enter(typeof(ApplicationColorModeScope));
         _originalColorMode = Application.ColorMode;
 
         if (_originalColorMode != colorMode)
@@ -28,16 +25,9 @@ public ApplicationColorModeScope(SystemColorMode colorMode)
 
     public void Dispose()
     {
-        try
+        if (Application.ColorMode != _originalColorMode)
         {
-            if (Application.ColorMode != _originalColorMode)
-            {
-                Application.SetColorMode(_originalColorMode);
-            }
-        }
-        finally
-        {
-            Monitor.Exit(typeof(ApplicationColorModeScope));
+            Application.SetColorMode(_originalColorMode);
         }
     }
 }

From 3278d8d11df23b8623d41c4fb69c51911ade7930 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Wed, 6 Nov 2024 20:53:34 -0800
Subject: [PATCH 06/18] Set theme to DarkMode_Explorer and round the corners
 with a small radius

---
 .../src/System/Windows/Forms/ToolTip/ToolTip.cs | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
index ced2f6b464b..7b2d90bd72e 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
@@ -3,6 +3,7 @@
 
 using System.ComponentModel;
 using System.Drawing;
+using Windows.Win32.Graphics.Dwm;
 
 namespace System.Windows.Forms;
 
@@ -20,6 +21,9 @@ public partial class ToolTip : Component, IExtenderProvider, IHandle<HWND>
     // These values are initialized using the default double-click time value.
     internal const int DefaultDelay = 500;
 
+    internal const string DarkModeIdentifier = "DarkMode";
+    internal const string ExplorerThemeIdentifier = "Explorer";
+
     // These values are copied from the ComCtl32's tooltip.
     private const int ReshowRatio = 5;
     private const int AutoPopRatio = 10;
@@ -715,10 +719,21 @@ private unsafe void CreateHandle()
             _window.CreateHandle(cp);
 
 #pragma warning disable WFO5001
-            if (SystemInformation.HighContrast || Application.IsDarkModeEnabled)
+            if (SystemInformation.HighContrast)
             {
                 PInvoke.SetWindowTheme(HWND, string.Empty, string.Empty);
             }
+            else if (Application.IsDarkModeEnabled)
+            {
+                DWM_WINDOW_CORNER_PREFERENCE roundSmall = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL;
+                PInvoke.DwmSetWindowAttribute(
+                    HWND,
+                    DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE,
+                    &roundSmall,
+                    sizeof(DWM_WINDOW_CORNER_PREFERENCE));
+
+                PInvokeCore.SendMessage(HWND, PInvoke.TTM_SETWINDOWTHEME, default, $"{DarkModeIdentifier}_{ExplorerThemeIdentifier}");
+            }
 #pragma warning restore WFO5001
         }
 

From f4d6102c60c2f3d08a7b600f576432bb64914b09 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Wed, 6 Nov 2024 22:11:29 -0800
Subject: [PATCH 07/18] Assert the rounded corner preference

---
 .../UnitTests/System/Windows/Forms/ToolTipTests.cs   | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
index 2be455f84c2..5e825a82559 100644
--- a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
+++ b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
@@ -6,6 +6,7 @@
 using System.Windows.Forms.Automation;
 using Moq;
 using Moq.Protected;
+using Windows.Win32.Graphics.Dwm;
 
 namespace System.Windows.Forms.Tests;
 
@@ -784,7 +785,7 @@ public void ToolTip_ToString_Invoke_ReturnsExpected()
 
 #pragma warning disable WFO5001
     [WinFormsFact]
-    public void ToolTip_DarkMode_GetColors_ReturnsExpected()
+    public unsafe void ToolTip_DarkMode_GetColors_ReturnsExpected()
     {
         if (SystemInformation.HighContrast)
         {
@@ -803,8 +804,17 @@ public void ToolTip_DarkMode_GetColors_ReturnsExpected()
         var textColor = PInvokeCore.SendMessage(toolTip, PInvoke.TTM_GETTIPTEXTCOLOR);
         Color foreColor = ColorTranslator.FromWin32((int)textColor);
 
+        DWMWINDOWATTRIBUTE dmwWindowAttribute = DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE;
+        DWM_WINDOW_CORNER_PREFERENCE cornerPreference;
+        PInvoke.DwmGetWindowAttribute(
+            toolTip.HWND,
+            dmwWindowAttribute,
+            &cornerPreference,
+            sizeof(DWM_WINDOW_CORNER_PREFERENCE));
+
         backColor.ToArgb().Should().Be(SystemColors.Info.ToArgb());
         foreColor.ToArgb().Should().Be(SystemColors.InfoText.ToArgb());
+        cornerPreference.Should().Be(DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL);
     }
 #pragma warning restore WFO5001
 

From a4ead96ece9d9842dd8c3d290bb8d675e070cee4 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Wed, 6 Nov 2024 23:12:49 -0800
Subject: [PATCH 08/18] Corner preference is supported starting with Windows 11
 Build 22000

---
 .../System/Windows/Forms/ToolTip/ToolTip.cs   | 15 ++++++-----
 .../System/Windows/Forms/ToolTipTests.cs      | 27 ++++++++++++++++---
 2 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
index 7b2d90bd72e..e62a266020c 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
@@ -725,12 +725,15 @@ private unsafe void CreateHandle()
             }
             else if (Application.IsDarkModeEnabled)
             {
-                DWM_WINDOW_CORNER_PREFERENCE roundSmall = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL;
-                PInvoke.DwmSetWindowAttribute(
-                    HWND,
-                    DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE,
-                    &roundSmall,
-                    sizeof(DWM_WINDOW_CORNER_PREFERENCE));
+                if (OsVersion.IsWindows11_OrGreater())
+                {
+                    DWM_WINDOW_CORNER_PREFERENCE roundSmall = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL;
+                    PInvoke.DwmSetWindowAttribute(
+                        HWND,
+                        DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE,
+                        &roundSmall,
+                        sizeof(DWM_WINDOW_CORNER_PREFERENCE));
+                }
 
                 PInvokeCore.SendMessage(HWND, PInvoke.TTM_SETWINDOWTHEME, default, $"{DarkModeIdentifier}_{ExplorerThemeIdentifier}");
             }
diff --git a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
index 5e825a82559..03bf1665e9b 100644
--- a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
+++ b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
@@ -785,7 +785,7 @@ public void ToolTip_ToString_Invoke_ReturnsExpected()
 
 #pragma warning disable WFO5001
     [WinFormsFact]
-    public unsafe void ToolTip_DarkMode_GetColors_ReturnsExpected()
+    public void ToolTip_DarkMode_GetColors_ReturnsExpected()
     {
         if (SystemInformation.HighContrast)
         {
@@ -804,6 +804,29 @@ public unsafe void ToolTip_DarkMode_GetColors_ReturnsExpected()
         var textColor = PInvokeCore.SendMessage(toolTip, PInvoke.TTM_GETTIPTEXTCOLOR);
         Color foreColor = ColorTranslator.FromWin32((int)textColor);
 
+        backColor.ToArgb().Should().Be(SystemColors.Info.ToArgb());
+        foreColor.ToArgb().Should().Be(SystemColors.InfoText.ToArgb());
+    }
+
+    [WinFormsFact]
+    public unsafe void ToolTip_DarkMode_GetCornerPreference_ReturnsExpected()
+    {
+        if (!OsVersion.IsWindows11_OrGreater())
+        {
+            return;
+        }
+
+        if (SystemInformation.HighContrast)
+        {
+            // We don't run this test in HighContrast mode.
+            return;
+        }
+
+        using ApplicationColorModeScope colorModeScope = new(colorMode: SystemColorMode.Dark);
+        using SubToolTip toolTip = new();
+
+        toolTip.Handle.Should().NotBe(IntPtr.Zero); // A workaround to create the toolTip native window Handle
+
         DWMWINDOWATTRIBUTE dmwWindowAttribute = DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE;
         DWM_WINDOW_CORNER_PREFERENCE cornerPreference;
         PInvoke.DwmGetWindowAttribute(
@@ -812,8 +835,6 @@ public unsafe void ToolTip_DarkMode_GetColors_ReturnsExpected()
             &cornerPreference,
             sizeof(DWM_WINDOW_CORNER_PREFERENCE));
 
-        backColor.ToArgb().Should().Be(SystemColors.Info.ToArgb());
-        foreColor.ToArgb().Should().Be(SystemColors.InfoText.ToArgb());
         cornerPreference.Should().Be(DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL);
     }
 #pragma warning restore WFO5001

From c34aa2df9eb62868656d3895538821d861e4d038 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Thu, 7 Nov 2024 20:35:08 -0800
Subject: [PATCH 09/18] Use default corner preference for balloon windows

---
 .../System/Windows/Forms/ToolTip/ToolTip.cs   | 14 +++++----
 .../System/Windows/Forms/ToolTipTests.cs      | 30 +++++++++----------
 2 files changed, 24 insertions(+), 20 deletions(-)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
index e62a266020c..dbda709998d 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
@@ -725,7 +725,7 @@ private unsafe void CreateHandle()
             }
             else if (Application.IsDarkModeEnabled)
             {
-                if (OsVersion.IsWindows11_OrGreater())
+                if (!_isBalloon && OsVersion.IsWindows11_OrGreater())
                 {
                     DWM_WINDOW_CORNER_PREFERENCE roundSmall = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL;
                     PInvoke.DwmSetWindowAttribute(
@@ -790,11 +790,15 @@ private unsafe void CreateHandle()
         // Set active status.
         PInvokeCore.SendMessage(this, PInvoke.TTM_ACTIVATE, (WPARAM)(BOOL)_active);
 
-        // Set background color.
-        PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPBKCOLOR, (WPARAM)_backColor);
+        if (BackColor != SystemColors.Info)
+        {
+            PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPBKCOLOR, (WPARAM)BackColor);
+        }
 
-        // Set text color.
-        PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPTEXTCOLOR, (WPARAM)_foreColor);
+        if (ForeColor != SystemColors.InfoText)
+        {
+            PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPTEXTCOLOR, (WPARAM)ForeColor);
+        }
 
         if (_toolTipIcon > 0 || !string.IsNullOrEmpty(_toolTipTitle))
         {
diff --git a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
index 03bf1665e9b..1460c69b446 100644
--- a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
+++ b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
@@ -785,7 +785,7 @@ public void ToolTip_ToString_Invoke_ReturnsExpected()
 
 #pragma warning disable WFO5001
     [WinFormsFact]
-    public void ToolTip_DarkMode_GetColors_ReturnsExpected()
+    public unsafe void ToolTip_DarkMode_GetColors_ReturnsExpected()
     {
         if (SystemInformation.HighContrast)
         {
@@ -798,18 +798,13 @@ public void ToolTip_DarkMode_GetColors_ReturnsExpected()
 
         toolTip.Handle.Should().NotBe(IntPtr.Zero); // A workaround to create the toolTip native window Handle
 
-        var backgroundColor = PInvokeCore.SendMessage(toolTip, PInvoke.TTM_GETTIPBKCOLOR);
-        Color backColor = ColorTranslator.FromWin32((int)backgroundColor);
-
-        var textColor = PInvokeCore.SendMessage(toolTip, PInvoke.TTM_GETTIPTEXTCOLOR);
-        Color foreColor = ColorTranslator.FromWin32((int)textColor);
-
-        backColor.ToArgb().Should().Be(SystemColors.Info.ToArgb());
-        foreColor.ToArgb().Should().Be(SystemColors.InfoText.ToArgb());
+        toolTip.BackColor.Should().Be(SystemColors.Info);
+        toolTip.ForeColor.Should().Be(SystemColors.InfoText);
     }
 
-    [WinFormsFact]
-    public unsafe void ToolTip_DarkMode_GetCornerPreference_ReturnsExpected()
+    [WinFormsTheory]
+    [BoolData]
+    public unsafe void ToolTip_DarkMode_GetCornerPreference_ReturnsExpected(bool value)
     {
         if (!OsVersion.IsWindows11_OrGreater())
         {
@@ -823,19 +818,24 @@ public unsafe void ToolTip_DarkMode_GetCornerPreference_ReturnsExpected()
         }
 
         using ApplicationColorModeScope colorModeScope = new(colorMode: SystemColorMode.Dark);
-        using SubToolTip toolTip = new();
+        using SubToolTip toolTip = new()
+        {
+            IsBalloon = value,
+        };
 
         toolTip.Handle.Should().NotBe(IntPtr.Zero); // A workaround to create the toolTip native window Handle
 
-        DWMWINDOWATTRIBUTE dmwWindowAttribute = DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE;
         DWM_WINDOW_CORNER_PREFERENCE cornerPreference;
         PInvoke.DwmGetWindowAttribute(
             toolTip.HWND,
-            dmwWindowAttribute,
+            DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE,
             &cornerPreference,
             sizeof(DWM_WINDOW_CORNER_PREFERENCE));
 
-        cornerPreference.Should().Be(DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL);
+        cornerPreference.Should().Be(
+            toolTip.IsBalloon
+                ? DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_DEFAULT
+                : DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL);
     }
 #pragma warning restore WFO5001
 

From 10e0bbb935d3a8f82cad9e0be01dd5b9e296da1e Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Sat, 9 Nov 2024 14:54:05 -0800
Subject: [PATCH 10/18] Initialize colors from dark mode explorer tooltip theme
 subclass

---
 .../System/Windows/Forms/ToolTip/ToolTip.cs   | 21 ++++++++++++++++---
 .../System/Windows/Forms/ToolTipTests.cs      | 16 ++++++++++++--
 2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
index dbda709998d..1d6f3d7b8e5 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
@@ -3,6 +3,7 @@
 
 using System.ComponentModel;
 using System.Drawing;
+using System.Windows.Forms.VisualStyles;
 using Windows.Win32.Graphics.Dwm;
 
 namespace System.Windows.Forms;
@@ -21,8 +22,7 @@ public partial class ToolTip : Component, IExtenderProvider, IHandle<HWND>
     // These values are initialized using the default double-click time value.
     internal const int DefaultDelay = 500;
 
-    internal const string DarkModeIdentifier = "DarkMode";
-    internal const string ExplorerThemeIdentifier = "Explorer";
+    internal const string TooltipThemeSubclassIdentifier = "Tooltip";
 
     // These values are copied from the ComCtl32's tooltip.
     private const int ReshowRatio = 5;
@@ -735,7 +735,22 @@ private unsafe void CreateHandle()
                         sizeof(DWM_WINDOW_CORNER_PREFERENCE));
                 }
 
-                PInvokeCore.SendMessage(HWND, PInvoke.TTM_SETWINDOWTHEME, default, $"{DarkModeIdentifier}_{ExplorerThemeIdentifier}");
+                PInvokeCore.SendMessage(
+                    HWND,
+                    PInvoke.TTM_SETWINDOWTHEME,
+                    default,
+                    $"{Control.DarkModeIdentifier}_{Control.ExplorerThemeIdentifier}");
+
+                var renderer = new VisualStyleRenderer(
+                    $"{Control.DarkModeIdentifier}_{Control.ExplorerThemeIdentifier}::{TooltipThemeSubclassIdentifier}",
+                    0,
+                    0);
+
+                _backColor = renderer.GetColor(ColorProperty.FillColor);
+                _foreColor = renderer.GetColor(ColorProperty.TextColor);
+
+                PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPBKCOLOR, (WPARAM)_backColor);
+                PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPTEXTCOLOR, (WPARAM)_foreColor);
             }
 #pragma warning restore WFO5001
         }
diff --git a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
index 1460c69b446..f113b2b6a86 100644
--- a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
+++ b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
@@ -4,6 +4,7 @@
 using System.ComponentModel;
 using System.Drawing;
 using System.Windows.Forms.Automation;
+using System.Windows.Forms.VisualStyles;
 using Moq;
 using Moq.Protected;
 using Windows.Win32.Graphics.Dwm;
@@ -793,13 +794,24 @@ public unsafe void ToolTip_DarkMode_GetColors_ReturnsExpected()
             return;
         }
 
+        var renderer = new VisualStyleRenderer(
+            $"{Control.DarkModeIdentifier}_{Control.ExplorerThemeIdentifier}::{ToolTip.TooltipThemeSubclassIdentifier}",
+            0,
+            0);
+        var fillColor = renderer.GetColor(ColorProperty.FillColor);
+        var textColor = renderer.GetColor(ColorProperty.TextColor);
         using ApplicationColorModeScope colorModeScope = new(colorMode: SystemColorMode.Dark);
         using SubToolTip toolTip = new();
 
         toolTip.Handle.Should().NotBe(IntPtr.Zero); // A workaround to create the toolTip native window Handle
 
-        toolTip.BackColor.Should().Be(SystemColors.Info);
-        toolTip.ForeColor.Should().Be(SystemColors.InfoText);
+        Color backColor = ColorTranslator.FromWin32((int)PInvokeCore.SendMessage(toolTip.HWND, PInvoke.TTM_GETTIPBKCOLOR));
+        Color foreColor = ColorTranslator.FromWin32((int)PInvokeCore.SendMessage(toolTip.HWND, PInvoke.TTM_GETTIPTEXTCOLOR));
+
+        backColor.Should().Be(fillColor);
+        foreColor.Should().Be(textColor);
+        toolTip.BackColor.Should().Be(fillColor);
+        toolTip.ForeColor.Should().Be(textColor);
     }
 
     [WinFormsTheory]

From d4c985be2496f6773f73ce898856cd1836fe71bb Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Sat, 9 Nov 2024 19:10:46 -0800
Subject: [PATCH 11/18] Set colors in a similar way as ListView and TreeView

---
 .../src/System/Windows/Forms/ToolTip/ToolTip.cs          | 9 ++++-----
 .../tests/UnitTests/System/Windows/Forms/ToolTipTests.cs | 1 +
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
index 1d6f3d7b8e5..8a6d2c9efbb 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
@@ -748,9 +748,6 @@ private unsafe void CreateHandle()
 
                 _backColor = renderer.GetColor(ColorProperty.FillColor);
                 _foreColor = renderer.GetColor(ColorProperty.TextColor);
-
-                PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPBKCOLOR, (WPARAM)_backColor);
-                PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPTEXTCOLOR, (WPARAM)_foreColor);
             }
 #pragma warning restore WFO5001
         }
@@ -805,15 +802,17 @@ private unsafe void CreateHandle()
         // Set active status.
         PInvokeCore.SendMessage(this, PInvoke.TTM_ACTIVATE, (WPARAM)(BOOL)_active);
 
-        if (BackColor != SystemColors.Info)
+#pragma warning disable WFO5001
+        if (BackColor != SystemColors.Info || Application.IsDarkModeEnabled)
         {
             PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPBKCOLOR, (WPARAM)BackColor);
         }
 
-        if (ForeColor != SystemColors.InfoText)
+        if (ForeColor != SystemColors.InfoText || Application.IsDarkModeEnabled)
         {
             PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPTEXTCOLOR, (WPARAM)ForeColor);
         }
+#pragma warning restore WFO5001
 
         if (_toolTipIcon > 0 || !string.IsNullOrEmpty(_toolTipTitle))
         {
diff --git a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
index f113b2b6a86..346b176368e 100644
--- a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
+++ b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
@@ -800,6 +800,7 @@ public unsafe void ToolTip_DarkMode_GetColors_ReturnsExpected()
             0);
         var fillColor = renderer.GetColor(ColorProperty.FillColor);
         var textColor = renderer.GetColor(ColorProperty.TextColor);
+
         using ApplicationColorModeScope colorModeScope = new(colorMode: SystemColorMode.Dark);
         using SubToolTip toolTip = new();
 

From 674c1c736e6fc04f8d1eede8b01e6f2303d0ee08 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Sun, 10 Nov 2024 21:35:07 -0800
Subject: [PATCH 12/18] Utilize theme for visual styles and remove the get
 colors test

---
 .../System/Windows/Forms/ToolTip/ToolTip.cs   | 23 ++++----------
 .../System/Windows/Forms/ToolTipTests.cs      | 31 -------------------
 2 files changed, 6 insertions(+), 48 deletions(-)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
index 8a6d2c9efbb..3013241633c 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
@@ -3,7 +3,6 @@
 
 using System.ComponentModel;
 using System.Drawing;
-using System.Windows.Forms.VisualStyles;
 using Windows.Win32.Graphics.Dwm;
 
 namespace System.Windows.Forms;
@@ -736,18 +735,10 @@ private unsafe void CreateHandle()
                 }
 
                 PInvokeCore.SendMessage(
-                    HWND,
-                    PInvoke.TTM_SETWINDOWTHEME,
-                    default,
-                    $"{Control.DarkModeIdentifier}_{Control.ExplorerThemeIdentifier}");
-
-                var renderer = new VisualStyleRenderer(
-                    $"{Control.DarkModeIdentifier}_{Control.ExplorerThemeIdentifier}::{TooltipThemeSubclassIdentifier}",
-                    0,
-                    0);
-
-                _backColor = renderer.GetColor(ColorProperty.FillColor);
-                _foreColor = renderer.GetColor(ColorProperty.TextColor);
+                   HWND,
+                   PInvoke.TTM_SETWINDOWTHEME,
+                   default,
+                   $"{Control.DarkModeIdentifier}_{Control.ExplorerThemeIdentifier}");
             }
 #pragma warning restore WFO5001
         }
@@ -802,17 +793,15 @@ private unsafe void CreateHandle()
         // Set active status.
         PInvokeCore.SendMessage(this, PInvoke.TTM_ACTIVATE, (WPARAM)(BOOL)_active);
 
-#pragma warning disable WFO5001
-        if (BackColor != SystemColors.Info || Application.IsDarkModeEnabled)
+        if (BackColor != SystemColors.Info)
         {
             PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPBKCOLOR, (WPARAM)BackColor);
         }
 
-        if (ForeColor != SystemColors.InfoText || Application.IsDarkModeEnabled)
+        if (ForeColor != SystemColors.InfoText)
         {
             PInvokeCore.SendMessage(this, PInvoke.TTM_SETTIPTEXTCOLOR, (WPARAM)ForeColor);
         }
-#pragma warning restore WFO5001
 
         if (_toolTipIcon > 0 || !string.IsNullOrEmpty(_toolTipTitle))
         {
diff --git a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
index 346b176368e..f93e3786d55 100644
--- a/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
+++ b/src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolTipTests.cs
@@ -4,7 +4,6 @@
 using System.ComponentModel;
 using System.Drawing;
 using System.Windows.Forms.Automation;
-using System.Windows.Forms.VisualStyles;
 using Moq;
 using Moq.Protected;
 using Windows.Win32.Graphics.Dwm;
@@ -785,36 +784,6 @@ public void ToolTip_ToString_Invoke_ReturnsExpected()
     }
 
 #pragma warning disable WFO5001
-    [WinFormsFact]
-    public unsafe void ToolTip_DarkMode_GetColors_ReturnsExpected()
-    {
-        if (SystemInformation.HighContrast)
-        {
-            // We don't run this test in HighContrast mode.
-            return;
-        }
-
-        var renderer = new VisualStyleRenderer(
-            $"{Control.DarkModeIdentifier}_{Control.ExplorerThemeIdentifier}::{ToolTip.TooltipThemeSubclassIdentifier}",
-            0,
-            0);
-        var fillColor = renderer.GetColor(ColorProperty.FillColor);
-        var textColor = renderer.GetColor(ColorProperty.TextColor);
-
-        using ApplicationColorModeScope colorModeScope = new(colorMode: SystemColorMode.Dark);
-        using SubToolTip toolTip = new();
-
-        toolTip.Handle.Should().NotBe(IntPtr.Zero); // A workaround to create the toolTip native window Handle
-
-        Color backColor = ColorTranslator.FromWin32((int)PInvokeCore.SendMessage(toolTip.HWND, PInvoke.TTM_GETTIPBKCOLOR));
-        Color foreColor = ColorTranslator.FromWin32((int)PInvokeCore.SendMessage(toolTip.HWND, PInvoke.TTM_GETTIPTEXTCOLOR));
-
-        backColor.Should().Be(fillColor);
-        foreColor.Should().Be(textColor);
-        toolTip.BackColor.Should().Be(fillColor);
-        toolTip.ForeColor.Should().Be(textColor);
-    }
-
     [WinFormsTheory]
     [BoolData]
     public unsafe void ToolTip_DarkMode_GetCornerPreference_ReturnsExpected(bool value)

From 26e4f93d539a9720353b152182e7b6a33147ed17 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Sun, 10 Nov 2024 21:40:12 -0800
Subject: [PATCH 13/18] Remove constant

---
 .../src/System/Windows/Forms/ToolTip/ToolTip.cs                 | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
index 3013241633c..efcfa1c6c4f 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/ToolTip/ToolTip.cs
@@ -21,8 +21,6 @@ public partial class ToolTip : Component, IExtenderProvider, IHandle<HWND>
     // These values are initialized using the default double-click time value.
     internal const int DefaultDelay = 500;
 
-    internal const string TooltipThemeSubclassIdentifier = "Tooltip";
-
     // These values are copied from the ComCtl32's tooltip.
     private const int ReshowRatio = 5;
     private const int AutoPopRatio = 10;

From 05412b8ee35a156db874bded0fec5f9344e59dc1 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Mon, 11 Nov 2024 19:45:15 -0800
Subject: [PATCH 14/18] Darken the ListView ToolTip in Dark mode

---
 .../Forms/Controls/ListView/ListView.cs        | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/Controls/ListView/ListView.cs b/src/System.Windows.Forms/src/System/Windows/Forms/Controls/ListView/ListView.cs
index 24a6688e4d7..630db12779d 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/Controls/ListView/ListView.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/Controls/ListView/ListView.cs
@@ -10,6 +10,7 @@
 using System.Runtime.InteropServices;
 using System.Windows.Forms.Layout;
 using System.Windows.Forms.VisualStyles;
+using Windows.Win32.Graphics.Dwm;
 using Windows.Win32.System.Variant;
 using Windows.Win32.UI.Accessibility;
 using Windows.Win32.UI.Input.KeyboardAndMouse;
@@ -4512,7 +4513,7 @@ protected override void OnFontChanged(EventArgs e)
         InvalidateColumnHeaders();
     }
 
-    protected override void OnHandleCreated(EventArgs e)
+    protected override unsafe void OnHandleCreated(EventArgs e)
     {
         // don't persist flipViewToLargeIconAndSmallIcon across handle recreations...
         FlipViewToLargeIconAndSmallIcon = false;
@@ -4533,6 +4534,21 @@ protected override void OnHandleCreated(EventArgs e)
             // Get the ListView's ColumnHeader handle:
             HWND columnHeaderHandle = (HWND)PInvokeCore.SendMessage(this, PInvoke.LVM_GETHEADER, (WPARAM)0, (LPARAM)0);
             PInvoke.SetWindowTheme(columnHeaderHandle, $"{DarkModeIdentifier}_{ItemsViewThemeIdentifier}", null);
+
+            // Get the ListView's ToolTip handle:
+            HWND toolTipHandle = (HWND)PInvokeCore.SendMessage(this, PInvoke.LVM_GETTOOLTIPS, (WPARAM)0, (LPARAM)0);
+            PInvoke.SetWindowTheme(toolTipHandle, $"{DarkModeIdentifier}_{ExplorerThemeIdentifier}", null);
+
+            // Round the corners of the ToolTip window.
+            if (OsVersion.IsWindows11_OrGreater())
+            {
+                DWM_WINDOW_CORNER_PREFERENCE roundSmall = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL;
+                PInvoke.DwmSetWindowAttribute(
+                    toolTipHandle,
+                    DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE,
+                    &roundSmall,
+                    sizeof(DWM_WINDOW_CORNER_PREFERENCE));
+            }
         }
 #pragma warning restore WFO5001
 

From 1e35f2ba312a69493163929007f6373624094dfe Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Mon, 11 Nov 2024 20:26:38 -0800
Subject: [PATCH 15/18] Darken the TreeView ToolTip in Dark mode

---
 .../Forms/Controls/TreeView/TreeView.cs       | 23 ++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TreeView/TreeView.cs b/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TreeView/TreeView.cs
index a7e66b35eb7..f26fdde2757 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TreeView/TreeView.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TreeView/TreeView.cs
@@ -8,6 +8,7 @@
 using System.Runtime.InteropServices;
 using System.Windows.Forms.Layout;
 using System.Windows.Forms.VisualStyles;
+using Windows.Win32.Graphics.Dwm;
 using Windows.Win32.System.Variant;
 using Windows.Win32.UI.Accessibility;
 using static System.Windows.Forms.TreeNode;
@@ -1524,6 +1525,26 @@ protected override unsafe void CreateHandle()
         }
 
         base.CreateHandle();
+
+#pragma warning disable WFO5001
+        if (Application.IsDarkModeEnabled)
+        {
+            // Get the TreeView's ToolTip handle:
+            HWND toolTipHandle = (HWND)PInvokeCore.SendMessage(HWND, PInvoke.TVM_GETTOOLTIPS, (WPARAM)0, (LPARAM)0);
+            PInvoke.SetWindowTheme(toolTipHandle, $"{DarkModeIdentifier}_{ExplorerThemeIdentifier}", null);
+
+            // Round the corners of the ToolTip window.
+            if (OsVersion.IsWindows11_OrGreater())
+            {
+                DWM_WINDOW_CORNER_PREFERENCE roundSmall = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL;
+                PInvoke.DwmSetWindowAttribute(
+                    toolTipHandle,
+                    DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE,
+                    &roundSmall,
+                    sizeof(DWM_WINDOW_CORNER_PREFERENCE));
+            }
+        }
+#pragma warning restore WFO5001
     }
 
     /// <summary>
@@ -1614,7 +1635,7 @@ internal void ForceScrollbarUpdate(bool delayed)
     /// <summary>
     ///  Called by ToolTip to poke in that Tooltip into this ComCtl so that the Native ChildToolTip is not exposed.
     /// </summary>
-    internal override void SetToolTip(ToolTip toolTip)
+    internal override unsafe void SetToolTip(ToolTip toolTip)
     {
         if (toolTip is null || !ShowNodeToolTips)
         {

From 7810b62a2ec359104c2b8a5627cdf87e1cb6b485 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Mon, 11 Nov 2024 20:35:58 -0800
Subject: [PATCH 16/18] Darken the TabControl ToolTip in Dark mode

---
 .../Forms/Controls/TabControl/TabControl.cs   | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TabControl/TabControl.cs b/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TabControl/TabControl.cs
index 618ce40bb14..06591c8179c 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TabControl/TabControl.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TabControl/TabControl.cs
@@ -7,6 +7,7 @@
 using System.Drawing.Design;
 using System.Text;
 using System.Windows.Forms.Layout;
+using Windows.Win32.Graphics.Dwm;
 using Windows.Win32.UI.Accessibility;
 
 namespace System.Windows.Forms;
@@ -967,6 +968,26 @@ protected override unsafe void CreateHandle()
         }
 
         base.CreateHandle();
+
+#pragma warning disable WFO5001
+        if (Application.IsDarkModeEnabled)
+        {
+            // Get the TabControl's ToolTip handle:
+            HWND toolTipHandle = (HWND)PInvokeCore.SendMessage(HWND, PInvoke.TCM_GETTOOLTIPS, (WPARAM)0, (LPARAM)0);
+            PInvoke.SetWindowTheme(toolTipHandle, $"{DarkModeIdentifier}_{ExplorerThemeIdentifier}", null);
+
+            // Round the corners of the ToolTip window.
+            if (OsVersion.IsWindows11_OrGreater())
+            {
+                DWM_WINDOW_CORNER_PREFERENCE roundSmall = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL;
+                PInvoke.DwmSetWindowAttribute(
+                    toolTipHandle,
+                    DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE,
+                    &roundSmall,
+                    sizeof(DWM_WINDOW_CORNER_PREFERENCE));
+            }
+        }
+#pragma warning restore WFO5001
     }
 
     private void DetachImageList(object? sender, EventArgs e) => ImageList = null;

From 3bcc1d2923c1f2a461fe53a4928c3c603cae8ad2 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Mon, 11 Nov 2024 21:48:04 -0800
Subject: [PATCH 17/18] Revert unnecessary change

---
 .../src/System/Windows/Forms/Controls/TreeView/TreeView.cs      | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TreeView/TreeView.cs b/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TreeView/TreeView.cs
index f26fdde2757..e177ff499d7 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TreeView/TreeView.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TreeView/TreeView.cs
@@ -1635,7 +1635,7 @@ internal void ForceScrollbarUpdate(bool delayed)
     /// <summary>
     ///  Called by ToolTip to poke in that Tooltip into this ComCtl so that the Native ChildToolTip is not exposed.
     /// </summary>
-    internal override unsafe void SetToolTip(ToolTip toolTip)
+    internal override void SetToolTip(ToolTip toolTip)
     {
         if (toolTip is null || !ShowNodeToolTips)
         {

From 625896fa97f0368cccfed11e01a46f6298143794 Mon Sep 17 00:00:00 2001
From: Brandon Williams <willibrandon@gmail.com>
Date: Tue, 12 Nov 2024 20:00:51 -0800
Subject: [PATCH 18/18] Move to OnHandleCreated

---
 .../Forms/Controls/TabControl/TabControl.cs   | 40 +++++++++----------
 .../Forms/Controls/TreeView/TreeView.cs       | 40 +++++++++----------
 2 files changed, 38 insertions(+), 42 deletions(-)

diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TabControl/TabControl.cs b/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TabControl/TabControl.cs
index 06591c8179c..a6329bfe012 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TabControl/TabControl.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TabControl/TabControl.cs
@@ -968,26 +968,6 @@ protected override unsafe void CreateHandle()
         }
 
         base.CreateHandle();
-
-#pragma warning disable WFO5001
-        if (Application.IsDarkModeEnabled)
-        {
-            // Get the TabControl's ToolTip handle:
-            HWND toolTipHandle = (HWND)PInvokeCore.SendMessage(HWND, PInvoke.TCM_GETTOOLTIPS, (WPARAM)0, (LPARAM)0);
-            PInvoke.SetWindowTheme(toolTipHandle, $"{DarkModeIdentifier}_{ExplorerThemeIdentifier}", null);
-
-            // Round the corners of the ToolTip window.
-            if (OsVersion.IsWindows11_OrGreater())
-            {
-                DWM_WINDOW_CORNER_PREFERENCE roundSmall = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL;
-                PInvoke.DwmSetWindowAttribute(
-                    toolTipHandle,
-                    DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE,
-                    &roundSmall,
-                    sizeof(DWM_WINDOW_CORNER_PREFERENCE));
-            }
-        }
-#pragma warning restore WFO5001
     }
 
     private void DetachImageList(object? sender, EventArgs e) => ImageList = null;
@@ -1242,7 +1222,7 @@ protected override void OnGotFocus(EventArgs e)
     ///  We do some work here to configure the handle.
     ///  Overriders should call base.OnHandleCreated()
     /// </summary>
-    protected override void OnHandleCreated(EventArgs e)
+    protected override unsafe void OnHandleCreated(EventArgs e)
     {
         if (!IsHandleCreated)
         {
@@ -1280,6 +1260,24 @@ protected override void OnHandleCreated(EventArgs e)
                     HWND.HWND_TOPMOST,
                     0, 0, 0, 0,
                     SET_WINDOW_POS_FLAGS.SWP_NOMOVE | SET_WINDOW_POS_FLAGS.SWP_NOSIZE | SET_WINDOW_POS_FLAGS.SWP_NOACTIVATE);
+
+#pragma warning disable WFO5001
+                if (Application.IsDarkModeEnabled)
+                {
+                    PInvoke.SetWindowTheme(tooltipHwnd, $"{DarkModeIdentifier}_{ExplorerThemeIdentifier}", null);
+
+                    // Round the corners of the ToolTip window.
+                    if (OsVersion.IsWindows11_OrGreater())
+                    {
+                        DWM_WINDOW_CORNER_PREFERENCE roundSmall = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL;
+                        PInvoke.DwmSetWindowAttribute(
+                            tooltipHwnd,
+                            DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE,
+                            &roundSmall,
+                            sizeof(DWM_WINDOW_CORNER_PREFERENCE));
+                    }
+                }
+#pragma warning restore WFO5001
             }
         }
 
diff --git a/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TreeView/TreeView.cs b/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TreeView/TreeView.cs
index e177ff499d7..709073ed50f 100644
--- a/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TreeView/TreeView.cs
+++ b/src/System.Windows.Forms/src/System/Windows/Forms/Controls/TreeView/TreeView.cs
@@ -1525,26 +1525,6 @@ protected override unsafe void CreateHandle()
         }
 
         base.CreateHandle();
-
-#pragma warning disable WFO5001
-        if (Application.IsDarkModeEnabled)
-        {
-            // Get the TreeView's ToolTip handle:
-            HWND toolTipHandle = (HWND)PInvokeCore.SendMessage(HWND, PInvoke.TVM_GETTOOLTIPS, (WPARAM)0, (LPARAM)0);
-            PInvoke.SetWindowTheme(toolTipHandle, $"{DarkModeIdentifier}_{ExplorerThemeIdentifier}", null);
-
-            // Round the corners of the ToolTip window.
-            if (OsVersion.IsWindows11_OrGreater())
-            {
-                DWM_WINDOW_CORNER_PREFERENCE roundSmall = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL;
-                PInvoke.DwmSetWindowAttribute(
-                    toolTipHandle,
-                    DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE,
-                    &roundSmall,
-                    sizeof(DWM_WINDOW_CORNER_PREFERENCE));
-            }
-        }
-#pragma warning restore WFO5001
     }
 
     /// <summary>
@@ -1860,7 +1840,7 @@ protected override bool IsInputKey(Keys keyData)
     protected virtual void OnDrawNode(DrawTreeNodeEventArgs e) =>
         _onDrawNode?.Invoke(this, e);
 
-    protected override void OnHandleCreated(EventArgs e)
+    protected override unsafe void OnHandleCreated(EventArgs e)
     {
         if (!IsHandleCreated)
         {
@@ -1914,6 +1894,24 @@ protected override void OnHandleCreated(EventArgs e)
         {
             PInvokeCore.SendMessage(this, PInvoke.TVM_SETTEXTCOLOR, 0, c.ToWin32());
         }
+
+        if (Application.IsDarkModeEnabled)
+        {
+            // Get the TreeView's ToolTip handle:
+            HWND toolTipHandle = (HWND)PInvokeCore.SendMessage(HWND, PInvoke.TVM_GETTOOLTIPS, (WPARAM)0, (LPARAM)0);
+            PInvoke.SetWindowTheme(toolTipHandle, $"{DarkModeIdentifier}_{ExplorerThemeIdentifier}", null);
+
+            // Round the corners of the ToolTip window.
+            if (OsVersion.IsWindows11_OrGreater())
+            {
+                DWM_WINDOW_CORNER_PREFERENCE roundSmall = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUNDSMALL;
+                PInvoke.DwmSetWindowAttribute(
+                    toolTipHandle,
+                    DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE,
+                    &roundSmall,
+                    sizeof(DWM_WINDOW_CORNER_PREFERENCE));
+            }
+        }
 #pragma warning restore WFO5001
 
         // Put the LineColor into the native control only if set.