C# Refreshable ListView Binding Issue

Unfortunately, there are many things that go wrong in your code. I believe, the main question is how to bind a collection of Animal objects to the ListView, that uses a DataTemplate defined as a resource. Besides that, you are wondering how the RefreshView and the Button are going to work correctly -but those are secondary questions and not really relevant to the main question. So, let's break everything down:

1. Name your "entity" class Animal instead of Animals. This is just a good practice suggestion but will allow you to name the collection Animals or AnimalsList which is also fine.

2. You are trying to use the DataTemplate resource incorrectly. Use the ItemTemplate property of the ListView component like this:

<ListView x:Name="ListView1" 
      ItemTemplate="{StaticResource AnimalsDataTemplate}">

3. You are trying to bind a List<T> to the ListView. That won't work. The recommended way is to use an ObservableCollection<T> instead of List<T>. The ObservableCollection<T> object raises the appropriate notifications when the list changes. If an item is added, updated, or removed from the list, or if the whole list is recreated, any bound objects to this collection are informed and redisplay themselves using the new information in the collection. Also, you need to use the MVVM pattern, which means you need a View Model class as the binding context of your MainPage. Last but not least, both the View Model class and the Animal class need to implement the INotifyPropertyChanged interface to let the UI know of changes to objects in your code. Here's the ViewModel class, MainPageViewModel:

public class MainPageViewModel : INotifyPropertyChanged
{
    private ObservableCollection<Animal> _AnimalsList = new();      
    public ObservableCollection<Animal> AnimalsList
    {
        get { return _AnimalsList; }
        set
        {
            _AnimalsList = value;
            RaisePropertyChanged(nameof(AnimalsList)));
        }
    }
      
    private bool _IsRefreshing;
    public bool IsRefreshing
    {
        get { return _IsRefreshing; }
        set
        {
            _IsRefreshing = value;
            RaisePropertyChanged(nameof(IsRefreshing));
        }
    }
      
    public MainPageViewModel()
    {
        ButtonCommand = new Command(() => IsRefreshing = true);
        RefreshCommand = new Command(() => Refresh());
    }
      
    public void Refresh()
    {
        IsRefreshing = true;
      
        AnimalsList = new ObservableCollection<Animal>()
        {
            new Animal("Jon", "22", "House"),
            new Animal("Jane", "20", "House"),
            new Animal("Bill", "300", "House")
        };
      
        IsRefreshing = false;
    }
      
    public event PropertyChangedEventHandler? PropertyChanged;
      
    public virtual void RaisePropertyChanged(string propertyName)
    {
        this.PropertyChanged?.Invoke(this,
            new PropertyChangedEventArgs(propertyName));
    }
      
    public ICommand? ButtonCommand { get; private set; }
    public ICommand? RefreshCommand { get; private set; }
}

The ViewModel defines AnimalsList, which will be bound to the ListView. It also defines IsRefreshing, which will be bound to the RefreshView and command object to bind to the RefreshView and Button controls. Setting IsRefreshing = true automatically triggers the RefreshCommand, just like pulling down would do. Please, note the implementation of INotifyPropertyChanged, which is essential.

And here's the Animal class. Again, please, note the implementation of INotifyPropertyChanged, which is absolutely essential:

public class Animal : INotifyPropertyChanged
{
    private string _Name { get; set; }
    private string _Location { get; set; }
    private string _Age { get; set; }
      
    public string Name
    {
        get { return _Name; }
        set
        {
            _Name = value;
            RaisePropertyChanged(nameof(Name));
        }
    }
      
    public string Location
    {
        get { return _Location; }
        set
        {
            _Location = value;
            RaisePropertyChanged(nameof(Location));
        }
    }
      
    public string Age
    {
        get { return _Age; }
        set
        {
            _Age = value;
            RaisePropertyChanged(nameof(Age));
        }
    }
      
    public override string ToString()
    {
        return Name;
    }
      
    public Animal(string name, string location, string age)
    {
        Name = name;
        Location = location;
        Age = age;
    }
      
    public event PropertyChangedEventHandler? PropertyChanged;
      
    public virtual void RaisePropertyChanged(string propertyName)
    {
        this.PropertyChanged?.Invoke(this,
            new PropertyChangedEventArgs(propertyName));
    }
}

4. The code-behind of MainPage sets the binding context of the view to the view model. It is best to override OnAppearing to set the binding context instead of doing so in the constructor:

public partial class MainPage : ContentPage
{
    private readonly MainPageViewModel _ViewModel;
 
    public MainPage()
    {
        InitializeComponent();
        _ViewModel = new MainPageViewModel();
    }
   
    protected override void OnAppearing()
    {
        base.OnAppearing();
        BindingContext = _ViewModel;
    }
}

5. Here's the XAML of MainPage:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="MauiApp1.MainPage">
   
    <ScrollView>
        <VerticalStackLayout
            Padding="30,0"
            Spacing="25">
   
            <RefreshView IsRefreshing="{Binding IsRefreshing}"
                         Command="{Binding RefreshCommand}"
                         x:Name="Refresh">
                   
                <ListView x:Name="ListView1" 
                      ItemsSource="{Binding AnimalsList}"
                      ItemTemplate="{StaticResource AnimalsDataTemplate}">
                </ListView>
                   
            </RefreshView>
            <Button Text="Refresh" 
                    Command="{Binding ButtonCommand}"></Button>
        </VerticalStackLayout>
    </ScrollView>
   
</ContentPage>

Please, note the bindings. For example, the ListView.ItemsSource binds to the AnimalsList public property of the MainPageViewModel class. Also, note that you want to define the RefreshView once, either in markup or in code (in your code you are defining it twice, both in markup and in code.)

Hope it helps.