WinForms Dark title bar on Windows 10

Question

I have a WinForms application which automatically adjusts to the dark/light theme on Windows 10. My problem is that the title bar of my window always stays white, regardless which theme the user selects.

Top is current, bottom is how I want it (simulated with Photoshop)

See explorer for example. That is not an UWP app, however it uses a dark title bar on Windows 1903 and newer (when a dark theme is selected).

How can I achieve the same thing? I do not want to use any custom titlebar as I want the application to look and behave like any native application on older Windows versions as well.

@User81772 The accepted answer (and all others) do not seem to work on modern versions of Windows — Jonas Kohl
– Jonas Kohl, Commented Jul 21, 2019 at 20:36
cmd.exe also has a dark titlebar when using the dark theme these days. In the past, I would have expected there to be a window style or API call to make it happen and maintain standard rendering (making the app future-proof when the Windows style changes). With today's MS, I wouldn't be surprised if both File Explorer and cmd.exe use custom hacks instead of them improving the actual OS and APIs for everything. :( — user108404
– user108404, Commented Aug 5, 2019 at 9:38
.NET 9 (preview) has introduced dark mode for the entire application including the title bar. Use Application.SetDefaultDarkMode(DarkMode.Enabled) in Program.cs. You can use DarkMode.Inherit to inherit the current theme from Windows settings. It can be light or dark. — Mubarrat
– Mubarrat, Commented Jun 29, 2024 at 14:49

Jonas Kohl · Accepted Answer · 2020-07-09 09:28:33Z

41

So after some long searching, I have finally found the answer for this. The trick is to use dwmapi.dll's DwmSetWindowAttribute and passing the undocumented constant DWMWA_USE_IMMERSIVE_DARK_MODE into the function. In C#, the code for this looks a little something like this (works with both WinForms and WPF):

/*
using System.Runtime.InteropServices;
*/

[DllImport("dwmapi.dll")]
private static extern int DwmSetWindowAttribute(IntPtr hwnd, int attr, ref int attrValue, int attrSize);

private const int DWMWA_USE_IMMERSIVE_DARK_MODE_BEFORE_20H1 = 19;
private const int DWMWA_USE_IMMERSIVE_DARK_MODE = 20;

private static bool UseImmersiveDarkMode(IntPtr handle, bool enabled)
{
    if (IsWindows10OrGreater(17763))
    {
        var attribute = DWMWA_USE_IMMERSIVE_DARK_MODE_BEFORE_20H1;
        if (IsWindows10OrGreater(18985))
        {
            attribute = DWMWA_USE_IMMERSIVE_DARK_MODE;
        }

        int useImmersiveDarkMode = enabled ? 1 : 0;
        return DwmSetWindowAttribute(handle, (int)attribute, ref useImmersiveDarkMode, sizeof(int)) == 0;
    }

    return false;
}

private static bool IsWindows10OrGreater(int build = -1)
{
    return Environment.OSVersion.Version.Major >= 10 && Environment.OSVersion.Version.Build >= build;
}

answered Jul 9, 2020 at 9:28

Jonas Kohl

1,1611 gold badge13 silver badges31 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

Alexander Dyagilev Over a year ago

In my case, I had to additionally hide/show window for this change to take effect.

Pk King X11 Over a year ago

Would be nice to know what other call is needed to force change it. But one way to do it without flashing the window or changing focus is to change the window opacity very slightly +/- relative to the current opacity by a small fraction like 0.0000000001 then return it back. This makes the required call that forces it to repaint.

Jonas Kohl Over a year ago

@PkKingX11 After looking at the reference source it seems that a call to SetWindowPos like follows seem to be needed: SetWindowPos(Handle, IntPtr.Zero, 0, 0, 0, 0, SWP_DRAWFRAME | SWP_NOACTIVATE | SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER); Although I have not tried this yet

Matt Over a year ago

Great, it works! Hint: Add UseImmersiveDarkMode(this.Handle, true); right after the InitializeComponent(); call in your form.

PSXGamerPro1 Over a year ago

The constant is no longer undocumented since I just opened this PR for it: github.com/MicrosoftDocs/sdk-api/pull/966/files. Also to force the window to repaint, one can call Invalidate() on the entire form or call SendMessageW with WM_NCPAINT to force an NCPAINT to happen again.

|

Lorenzo Lotti · Accepted Answer · 2020-11-20 09:50:02Z

14

The fastest way:

[DllImport("DwmApi")] //System.Runtime.InteropServices
private static extern int DwmSetWindowAttribute(IntPtr hwnd, int attr, int[] attrValue, int attrSize);

protected override void OnHandleCreated(EventArgs e)
{
    if (DwmSetWindowAttribute(Handle, 19, new[] { 1 }, 4) != 0)
        DwmSetWindowAttribute(Handle, 20, new[] { 1 }, 4);
}

answered Nov 20, 2020 at 9:50

Lorenzo Lotti

1411 silver badge4 bronze badges

2 Comments

StarShine Over a year ago

You may want to give a bit more details what those values mean exactly, or better yet use the functions that map literals to object identifiers.

BlueMystic Over a year ago

this just works!! ^_^

Angelo Cresta · Accepted Answer · 2022-12-12 11:33:43Z

3

For the solution from Jonas Kohl, remember that for .net fw 4.8.1 and prior, the version returned is not ok, fixed in .Net6, here a snippet (.Net 5 is not managed):

    private static bool IsWindows10OrGreater(int build = -1)
    {
        return WindowsVersion() >= 10 && WindowsBuildNumber() >= build;
    }

    public static int WindowsVersion()
    {
     //for .Net4.8 and Minor
     #if NETFRAMEWORK
        int result = 10;
        var reg = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\Windows NT\CurrentVersion");
        string[] productName = reg.GetValue("ProductName").ToString().Split((char)32);
        int.TryParse(productName[1], out result);
        return result;
     #else
        //fixed in .Net6
        return System.Environment.OSVersion.Version.Major;
     #endif
    }

    public static int WindowsBuildNumber()
    {
        //for .Net4.8 and Minor
    #if NETFRAMEWORK
        int result = 22000;
        var reg = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\Windows NT\CurrentVersion");
        string buildNumber = reg.GetValue("CurrentBuildNumber").ToString();
        int.TryParse(buildNumber, out result);
        return result;
    #endif

    #if NET
        //fixed in .Net6
        return System.Environment.OSVersion.Version.Build;
    #endif
    }

edited Dec 12, 2022 at 11:33

answered Dec 12, 2022 at 11:25

Angelo Cresta

2273 silver badges9 bronze badges

1 Comment

Jonas Kohl Over a year ago

If you add an app.manifest with the tag <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" /> you will also get back the correct value for Environment.OSVersion.Version

VIRUXE · Accepted Answer · 2024-09-26 18:09:27Z

1

.NET 9 now has Application.SetColorMode. Where SystemColorMode.Dark sets a "Dark Mode". But apparently only works on Windows 11.

answered Sep 26, 2024 at 18:09

VIRUXE

312 bronze badges

Comments

PhilH · Accepted Answer · 2023-10-07 10:43:06Z

0

Just a note about useage.

I placed the call to use dark mode method in a form's constructor and found that forms inheriting from this form were having problems with StartPosition (possibly the base form, but that's untested).

Changing an inheriting form's StartPosition in the designer to any other value, caused the Location to be used instead (Location was being added to inheriting form's designer code - manually deleting it worked, but it's not a good solution.) Reversing the change does not undo the problem.

Solution is to place the dark mode call in the Load event (tested only on .Net 6)

answered Oct 7, 2023 at 10:43

PhilH

112 bronze badges

1 Comment

Jonas Kohl Over a year ago

The right place for this would be in OnHandleCreated

Collectives™ on Stack Overflow

WinForms Dark title bar on Windows 10

5 Answers 5

6 Comments

2 Comments

1 Comment

Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

6 Comments

2 Comments

1 Comment

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related