Avalonia video 3

//parte .axaml (a seguire la parte per .cs
<Window 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"
        mc:Ignorable="d" d:DesignWidth="400" d:DesignHeight="400"
        x:Class="AvaloniaTemplate1.MainWindow"
        Title="Iscrizione Newsletter"
        Width="400" Height="400">

    <StackPanel Margin="20" Spacing="10">
        <TextBlock Text="Iscriviti alla nostra Newsletter!"
                 FontSize="24"
                 HorizontalAlignment="Center"
                 Margin="0,0,0,20"/>

        <TextBlock Text="Nome:"/>
        <TextBox x:Name="NomeTextBox"
                Watermark="Inserisci il tuo nome"/>

        <TextBlock Text="Email:"/>
        <TextBox x:Name="EmailTextBox"
                Watermark="Inserisci la tua email"/>

        <CheckBox x:Name="PrivacyCheckBox"
                 Margin="0,10"
                 Content="Accetto l'informativa sulla privacy"/>

        <Button x:Name="IscrivitiButton"
                Content="Iscriviti"
                HorizontalAlignment="Center"
                HorizontalContentAlignment="Center"
                VerticalContentAlignment="Center"
                Width="150"
                Height="40"

                Margin="0,20,0,0" />

                <!-- Click="IscrivitiButton_OnClick" -->

        <TextBlock x:Name="MessaggioTextBlock"
                   HorizontalAlignment="Center"
                   Foreground="Green"/>
    </StackPanel>
</Window>

//PARTE CS OCCHIO A SISTEMARE IL NAMESPACE!
using Avalonia.Controls;
using Avalonia.Interactivity;
using Avalonia.Media;

namespace AvaloniaTemplate1;

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        SetupGestoriEvento();
    }

    private void SetupGestoriEvento()
    {
        IscrivitiButton.Click += IscrivitiButton_OnClick;
    }


    private void IscrivitiButton_OnClick(object? sender, RoutedEventArgs e)
    {
        if (string.IsNullOrWhiteSpace(NomeTextBox.Text))
        {
            MessaggioTextBlock.Foreground = new SolidColorBrush(Colors.Red);
            MessaggioTextBlock.Text = "Inserire nome";
        }

    }
}