YOUserbase/UserOverviewPage.xaml.cs

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;

namespace YOUserbase;

public partial class UserOverviewPage : ContentPage {
	public int _index = 0;

	private string details;
	private string firstname;
	private string lastname;
	private string birthDate;
	public string Details { get => details; set => SetProperty (ref details, value); }
	public string Firstname { get => firstname; set => SetProperty (ref firstname, value); }
	public string Lastname { get => lastname; set => SetProperty (ref lastname, value); }
	public string BirthDate { get => birthDate; set => SetProperty (ref birthDate, value); }

	public UserOverviewPage ()
	{
		InitializeComponent ();
		users.ItemsSource = Data.Users;
	}

	private async void OnAdd (object sender, EventArgs e)
	{
		await Navigation.PushAsync (new CreateUserPage ());
		Console.WriteLine(Data.Users);
	}

	private async void OnDeleteItem(object sender, EventArgs e) {
		Button btn = (Button)sender;
		var id = Int32.Parse(btn.ClassId);
		var user = Data.Users.FirstOrDefault(usr => usr.Id == id);
		var action = await DisplayAlert("Irreversible action", "Do you really want to delete this user?", "Yes", "No");
		if (action) { 
            Data.Users.Remove(user);
        }
    }

	private async void OnEditItem (object sender, EventArgs e)
	{
		Button btn = (Button)sender;
		var id = Int32.Parse(btn.ClassId);
		var user = Data.Users.FirstOrDefault(usr => usr.Id == id);
		await Navigation.PushAsync(new CreateUserPage(user));
	}

	protected bool SetProperty<T> (ref T field, T newValue, [CallerMemberName] string propertyName = null)
	{
		if (!Equals (field, newValue)) {
			field = newValue;
			// PropertyChanged?.Invoke (this, new PropertyChangedEventArgs (propertyName));
			return true;
		}

		return false;
	}
}