Added OpenDirectoryDialogService

src/RolandK.AvaloniaExtensions.TestApp/MainWindow.axaml

@@ -20,8 +20,10 @@
             <DockPanel LastChildFill="True">
                 <Menu DockPanel.Dock="Top">
                     <MenuItem Header="File">
-                        <MenuItem Header="Open"
+                        <MenuItem Header="Open file"
                                   Command="{Binding OpenFileCommand}" />
+                        <MenuItem Header="Open directory"
+                                  Command="{Binding OpenDirectoryCommand}" />
 
                         <Separator />
 

src/RolandK.AvaloniaExtensions.TestApp/MainWindowViewModel.cs

@@ -48,7 +48,24 @@ public async Task OpenFileAsync()
 
         await srvMessageBox.ShowAsync(
             "Open file",
-            $"File {selectedFile} selected", MessageBoxButtons.Ok);
+            $"File {selectedFile} selected", 
+            MessageBoxButtons.Ok);
+    }
+
+    [RelayCommand]
+    public async Task OpenDirectoryAsync()
+    {
+        var srvOpenDirectory = this.GetViewService<IOpenDirectoryViewService>();
+        var srvMessageBox = this.GetViewService<IMessageBoxViewService>();
+
+        var selectedDirectory = await srvOpenDirectory.ShowOpenDirectoryDialogAsync(
+            "Open directory");
+        if (string.IsNullOrEmpty(selectedDirectory)) { return; }
+
+        await srvMessageBox.ShowAsync(
+            "Open directory",
+            $"Directory {selectedDirectory} selected",
+            MessageBoxButtons.Ok);
     }
 
     [RelayCommand]

src/RolandK.AvaloniaExtensions/ViewServices/DefaultViewServices.cs

@@ -33,6 +33,14 @@ internal static class DefaultViewServices
 
             return new MessageBoxViewControlService(dlgHostControl);
         }
+
+        if (viewServiceType == typeof(IOpenDirectoryViewService))
+        {
+            var parentWindow = host.FindLogicalAncestorOfType<Window>(true);
+            if (parentWindow == null) { return null; }
+
+            return new OpenDirectoryDialogService(parentWindow);
+        }
 
         return null;
     }

src/RolandK.AvaloniaExtensions/ViewServices/FileDialogs/OpenDirectoryDialogService.cs

@@ -0,0 +1,33 @@
+using System.Web;
+using Avalonia.Controls;
+using Avalonia.Platform.Storage;
+using RolandK.AvaloniaExtensions.ViewServices.Base;
+
+namespace RolandK.AvaloniaExtensions.ViewServices.FileDialogs;
+
+public class OpenDirectoryDialogService : ViewServiceBase, IOpenDirectoryViewService
+{
+    private Window _parent;
+
+    public OpenDirectoryDialogService(Window parent)
+    {
+        _parent = parent;
+    }
+
+    /// <inheritdoc />
+    public async Task<string?> ShowOpenDirectoryDialogAsync(string title)
+    {
+        var options = new FolderPickerOpenOptions();
+        options.AllowMultiple = false;
+        options.Title = title;
+
+        var selectedFolders = await _parent.StorageProvider.OpenFolderPickerAsync(options);
+        if ((selectedFolders == null) ||
+            (selectedFolders.Count == 0))
+        {
+            return null;
+        }
+
+        return HttpUtility.UrlDecode(selectedFolders[0].Path.AbsolutePath);
+    }
+}