feat: implement RefreshContainer.

demo/Semi.Avalonia.Demo/Pages/RefreshContainerDemo.axaml.cs

@@ -1,14 +1,46 @@
-using Avalonia;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.Threading.Tasks;
 using Avalonia.Controls;
-using Avalonia.Interactivity;
-using Avalonia.Markup.Xaml;
+using CommunityToolkit.Mvvm.ComponentModel;
 
 namespace Semi.Avalonia.Demo.Pages;
 
 public partial class RefreshContainerDemo : UserControl
 {
+    private RefreshContainerDemoViewModel _viewModel;
+
     public RefreshContainerDemo()
     {
         InitializeComponent();
+
+        _viewModel = new RefreshContainerDemoViewModel();
+
+        DataContext = _viewModel;
+    }
+
+    private async void RefreshContainerPage_RefreshRequested(object? sender, RefreshRequestedEventArgs e)
+    {
+        var deferral = e.GetDeferral();
+
+        await _viewModel.AddToTop();
+
+        deferral.Complete();
+    }
+}
+
+public class RefreshContainerDemoViewModel : ObservableObject
+{
+    public ObservableCollection<string> Items { get; }
+
+    public RefreshContainerDemoViewModel()
+    {
+        Items = new ObservableCollection<string>(Enumerable.Range(1, 200).Select(i => $"Item {i}"));
+    }
+
+    public async Task AddToTop()
+    {
+        await Task.Delay(1000);
+        Items.Insert(0, $"Item {200 - Items.Count}");
     }
 }