`NoChrome` not work in Ubuntu

<Window
    x:Class="ColorMC.UI.MainWindow"
    xmlns="https://github.com/avaloniaui"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:views="clr-namespace:ColorMC.UI.Views"
    Width="800"
    Height="450"
    MinWidth="800"
    MinHeight="450"
    d:DesignHeight="450"
    d:DesignWidth="800"
    ExtendClientAreaChromeHints="NoChrome"
    ExtendClientAreaTitleBarHeightHint="-1"
    ExtendClientAreaToDecorationsHint="True"
    mc:Ignorable="d">
    <Grid>
        <views:HeadControl
            Title="ColorMC 主界面"
            HorizontalAlignment="Stretch"
            VerticalAlignment="Top" />
        <Grid Margin="0,30,0,0">
            <Rectangle
                Fill="#FFF4F4F5"
                Stroke="#FF5ABED6"
                StrokeThickness="3" />

            <views:InfoControl Name="Info" IsVisible="False" />
        </Grid>
    </Grid>
</Window>

windows: ubuntu:

[kekekeks]

We are planning to create some kind of an API for handling CSD, but only for environments where it makes sense (like mentioned GNOME). Sway and KDE users won’t be happy with a custom-drawn border.

[yll690]

I have removed the Ubuntu title bar successfully using XInternAtom and XChangeProperty. Then I found a simpler way: just set Window.SystemDecorations to BorderOnly then the title bar disappears and it is compatible with Windows. However, the window losts many features in Ubuntu like window shadow, drag move, resize, double click to maximize and so on. We have to implement them ourselves.