feat: Add ManagedFileChooser

demo/Semi.Avalonia.Demo/Pages/ManagedFileChooserDemo.axaml

@@ -0,0 +1,16 @@
+<UserControl
+    x:Class="Semi.Avalonia.Demo.Pages.ManagedFileChooserDemo"
+    xmlns="https://github.com/avaloniaui"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:dialogs="clr-namespace:Avalonia.Dialogs;assembly=Avalonia.Dialogs"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    d:DesignHeight="450"
+    d:DesignWidth="800"
+    mc:Ignorable="d">
+    <StackPanel HorizontalAlignment="Left" Spacing="10">
+        <Button Name="openFileDialog">Open File</Button>
+        <Button Name="selectFolderDialog">Select Folder</Button>
+        <Button Name="saveFileDialog">Save File</Button>
+    </StackPanel>
+</UserControl>

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

@@ -0,0 +1,72 @@
+using System;
+using System.Collections.Generic;
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Dialogs;
+using Avalonia.Interactivity;
+using Avalonia.Markup.Xaml;
+using Avalonia.Platform.Storage;
+
+namespace Semi.Avalonia.Demo.Pages;
+
+public partial class ManagedFileChooserDemo : UserControl
+{
+    public ManagedFileChooserDemo()
+    {
+        InitializeComponent();
+        openFileDialog.Click += OpenFileDialog;
+        selectFolderDialog.Click += SelectFolderDialog;
+        saveFileDialog.Click += SaveFileDialog;
+    }
+
+    private async void OpenFileDialog(object sender, RoutedEventArgs args)
+    {
+        IStorageProvider sp = GetStorageProvider();
+        var result = await sp.OpenFilePickerAsync(new FilePickerOpenOptions()
+        {
+            Title = "Open File",
+            FileTypeFilter = GetFileTypes(),
+            AllowMultiple = true,
+        });
+    }
+    private async void SelectFolderDialog(object sender, RoutedEventArgs args)
+    {
+        IStorageProvider sp = GetStorageProvider();
+        var result = await sp.OpenFolderPickerAsync(new FolderPickerOpenOptions()
+        {
+            Title = "Select Folder",
+            AllowMultiple = true,
+        });
+    }
+    private async void SaveFileDialog(object sender, RoutedEventArgs args)
+    {
+        IStorageProvider sp = GetStorageProvider();
+        var result = await sp.SaveFilePickerAsync(new FilePickerSaveOptions()
+        {
+            Title = "Open File",
+        });
+    }
+    
+    private IStorageProvider GetStorageProvider()
+    {
+        return new ManagedStorageProvider<Window>(GetWindow(), null);
+    }
+
+    private static string FullPathOrName(IStorageItem? item)
+    {
+        if (item is null) return "(null)";
+        return item.TryGetUri(out var uri) ? uri.ToString() : item.Name;
+    }
+
+    Window GetWindow() => this.VisualRoot as Window ?? throw new NullReferenceException("Invalid Owner");
+    TopLevel GetTopLevel() => this.VisualRoot as TopLevel ?? throw new NullReferenceException("Invalid Owner");
+    
+    List<FilePickerFileType>? GetFileTypes()
+    {
+        return new List<FilePickerFileType>
+        {
+            FilePickerFileTypes.All,
+            FilePickerFileTypes.TextPlain
+        };
+    }
+}

demo/Semi.Avalonia.Demo/Views/MainView.axaml

@@ -60,6 +60,9 @@
         <TabItem Header="ListBox">
             <pages:ListBoxDemo />
         </TabItem>
+        <TabItem Header="ManagedFileChooser">
+            <pages:ManagedFileChooserDemo />
+        </TabItem>
         <TabItem Header="Menu">
             <pages:MenuDemo />
         </TabItem>