[Bug] MacOS Xamarin Forms does not support dark mode

[steven-pearson]

Description

Out of box XF does not support Dark Mode

Steps to Reproduce

1. Create a Cross platform app iOS+Android
2. Add a macOS Project
3. Amend Mac project to use Xamarin Forms (see below)
4. Run app

Steps to convert to XF

Change AppDelegate to ...

public class AppDelegate : FormsApplicationDelegate
{
    NSWindow _window;

    public override NSWindow MainWindow
    {
        get { return _window; }
    }


    public AppDelegate()
    {
        var style = NSWindowStyle.Closable | NSWindowStyle.Resizable | NSWindowStyle.Titled;

        var rect = new CoreGraphics.CGRect(200, 200, 800, 600);
        _window = new NSWindow(rect, style, NSBackingStore.Buffered, false);
        _window.TitleVisibility = NSWindowTitleVisibility.Hidden;
        _window.Title = "No Dark Mode";
    }

    public override void DidFinishLaunching(NSNotification notification)
    {
        Forms.Init();
        LoadApplication(new App());
        base.DidFinishLaunching(notification);
    }

Change MainClass to
static void Main(string[] args)
{
NSApplication.Init();
NSApplication.SharedApplication.Delegate = new AppDelegate();
NSApplication.Main(args);
}

Remove story board reference from info.plist

Expected Behavior

Window should be in dark mode

Actual Behavior

Window is not in dark mode, always in light mode.

Basic Information

Run the macOS app before converting to XF and confirm that the Window shows in dark mode.

• Version with issue: latest
• Last known good version: none
• IDE: VS4Mac
• Platform Target Frameworks:
  • macOS: Catalina
• Nuget Packages: XF 4.4
• Affected Devices:

Screenshots

Reproduction Link

[VladislavAntonyuk]

You have to manually implement this logic. To enable dark theme add this code

NSApplication.SharedApplication.SetAppearance(NSAppearance.GetAppearance(NSAppearance.NameDarkAqua));

[steven-pearson]

Thanks for the info. For anyone wanting to implement the location of the change is important, must happen after Init of XF i.e.

    public override void DidFinishLaunching(NSNotification notification)
    {
        Forms.Init();

        // Set after XF is initialised
       NSApplication.SharedApplication.SetAppearance(NSAppearance.GetAppearance(NSAppearance.NameDarkAqua));

        LoadApplication(new App());

        // Insert code here to initialize your application
        base.DidFinishLaunching(notification);
    }

[jfversluis]

I have taken a quick look at this. I got the theme detection working and our own AppTheme concept pretty easily. We also have to remove hard-coded colors. The weird thing is though that some elements do update during runtime and other don't and I can't really put my finger on the why.

I'll revisit later, just putting this here in case anyone might have an idea :)