downkyicore/DownKyi/Views/MainWindow.axaml

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:vm="using:DownKyi.ViewModels"
        xmlns:prism="http://prismlibrary.com/"
        x:Class="DownKyi.Views.MainWindow"
        x:DataType="vm:MainWindowViewModel"
        prism:ViewModelLocator.AutoWireViewModel="True"
        Width="1100"
        Height="750"
        MinWidth="800"
        MinHeight="550"
        Title="{DynamicResource AppName}"
        Icon="/Resources/favicon.ico"
        xmlns:i="using:Avalonia.Xaml.Interactivity"
        xmlns:ia="clr-namespace:Avalonia.Xaml.Interactions.Core;assembly=Avalonia.Xaml.Interactions"
        WindowState="{Binding WinState}">

    <i:Interaction.Behaviors>
        <ia:EventTriggerBehavior EventName="Closing">
            <ia:InvokeCommandAction Command="{Binding ClosingCommand}" />
        </ia:EventTriggerBehavior>
        <ia:EventTriggerBehavior EventName="Opened">
            <ia:InvokeCommandAction Command="{Binding LoadedCommand}" />
        </ia:EventTriggerBehavior>
    </i:Interaction.Behaviors>
    <Grid RowDefinitions="*">
        <ContentControl prism:RegionManager.RegionName="ContentRegion" />

        <Border
            MinHeight="30"
            Margin="0,0,0,20"
            HorizontalAlignment="Center"
            VerticalAlignment="Bottom"
            Background="{DynamicResource BrushBackgroundDark}"
            CornerRadius="15"
            IsVisible="{Binding MessageVisibility}">
            <TextBlock
                Margin="15,5,15,5"
                HorizontalAlignment="Center"
                VerticalAlignment="Center"
                Background="{x:Null}"
                FontSize="12"
                Foreground="{DynamicResource BrushForegroundDark}"
                Text="{Binding Message}"
                TextAlignment="Center" />
        </Border>
    </Grid>
</Window>