feat!(threading): Use `ValueTask` for potentially synchronous operations by pomianowski · Pull Request #1693 · lepoco/wpfui

pomianowski · 2026-04-23T14:48:56Z

Pull request type

Please check the type of change your PR introduces:

Copilot

Pull request overview

Updates the Wpf.Ui library’s navigation/threading async surface area to use ValueTask where operations may complete synchronously, and adjusts repo tooling/metadata to align with the next major version and new solution format.

Changes:

Breaking change: migrate INavigationAware to ValueTask and update navigation notification flow to avoid allocations for synchronous completions.
Refactor snackbar show/hide pipeline to consolidate hide logic and reduce async state-machine overhead.
Repository/tooling updates: introduce Wpf.Ui.slnx, adjust build/CI scripts, and bump package/assembly versioning toward 5.0.0.

Reviewed changes

Copilot reviewed 27 out of 28 changed files in this pull request and generated 11 comments.

Show a summary per file

File	Description
src/Wpf.Ui/Wpf.Ui.csproj	Adds conditional package references related to `ValueTask` support for older TFMs.
src/Wpf.Ui/Extensions/ContentDialogServiceExtensions.cs	Minor object creation syntax adjustment.
src/Wpf.Ui/Controls/Snackbar/SnackbarPresenter.cs	Refactors snackbar lifecycle methods and cancellation behavior.
src/Wpf.Ui/Controls/Snackbar/Snackbar.cs	Adjusts async API flow for immediate vs queued display.
src/Wpf.Ui/Controls/NavigationView/NavigationViewContentPresenter.cs	Converts navigation notifications to `ValueTask` and adds fire-and-forget observation helper.
src/Wpf.Ui.Gallery/Views/Windows/MonacoWindow.xaml	Updates status bar text to reference the new solution format.
src/Wpf.Ui.Gallery/ViewModels/ViewModel.cs	Updates navigation hooks to `ValueTask`.
src/Wpf.Ui.Gallery/Controllers/MonacoController.cs	Refactors controller to primary constructor and removes unnecessary `async`/`await` usage.
src/Wpf.Ui.Extension.Template.Compact/Wpf.Ui.Compact.csproj	Updates template package references for the next major version.
src/Wpf.Ui.Extension.Template.Compact/ViewModels/Pages/DataViewModel.cs	Updates template navigation hooks toward `ValueTask`.
src/Wpf.Ui.Abstractions/Wpf.Ui.Abstractions.csproj	Adds conditional package reference for `ValueTask` support on older TFMs.
src/Wpf.Ui.Abstractions/Controls/NavigationAware.cs	Updates base navigation-aware class to `ValueTask`.
src/Wpf.Ui.Abstractions/Controls/INavigationAware.cs	Breaking change: interface methods now return `ValueTask`.
samples/Wpf.Ui.Demo.Mvvm/ViewModels/ViewModel.cs	Updates sample navigation hooks to `ValueTask`.
samples/Wpf.Ui.Demo.Dialogs/MainWindow.xaml.cs	Removes unnecessary `async` state-machine where possible for dialog show.
docs/index.md	Trims whitespace in docs content.
build.ps1	Updates restore command to reference the new solution format.
Wpf.Ui.slnx	Adds new XML-based solution file.
Wpf.Ui.sln.DotSettings	Adds solution-level IDE dictionary settings.
Wpf.Ui.sln	Removes the legacy `.sln`.
Wpf.Ui.Library.slnf	Removes legacy solution filter.
Wpf.Ui.Gallery.slnf	Removes legacy solution filter.
Directory.Packages.props	Adds package version entry for `System.Threading.Tasks.Extensions` and related adjustments.
Directory.Build.props	Bumps repo/package version toward `5.0.0-preview.1`.
.github/workflows/wpf-ui-cd-extension.yaml	Updates restore/build steps and formatting.
.github/copilot-instructions.md	Removes references to deleted solution filters.
.editorconfig	Updates file-glob formatting rules for solution/config files.
.claude/settings.local.json	Updates local tool allowlist entries.

Copilot · 2026-04-23T16:01:47Z

+        // NOTE: Post hide token, can we handle it better?
+        await Task.Delay(300, cancellationToken);


HideSnackbar passes cancellationToken into the post-hide delay (Task.Delay(300, cancellationToken)) but does not handle OperationCanceledException there. If the token is canceled during this delay (e.g., when HideCurrent() cancels CancellationTokenSource), the exception will propagate and can break ShowQueuedSnackbarsAsync() / ImmediatelyDisplay() which await this task. Either don't cancel the post-hide delay, or catch cancellation there to preserve the previous "best-effort" behavior.

Suggested change

// NOTE: Post hide token, can we handle it better?

await Task.Delay(300, cancellationToken);

try

{

await Task.Delay(300, cancellationToken);

}

catch (OperationCanceledException)

{

}

Copilot · 2026-04-23T16:01:48Z

+        if (Content is IDisposable disposableContent)
+        {
+            disposableContent.Dispose();
+        }

        Content = null;


HideSnackbar disposes Content (and then sets Content = null) rather than operating on snackbarToHide. This is fragile if Content changes before the method reaches this point (e.g., future refactors that allow overlapping show/hide operations), and it can dispose/clear the wrong snackbar. Prefer disposing/clearing based on snackbarToHide and only clearing Content if it still refers to that same instance.

Suggested change

if (Content is IDisposable disposableContent)

{

disposableContent.Dispose();

}

Content = null;

if (snackbarToHide is IDisposable disposableSnackbar)

{

disposableSnackbar.Dispose();

}

if (ReferenceEquals(Content, snackbarToHide))

{

Content = null;

}

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Nuklon · 2026-04-23T16:42:12Z

+    )
+    {
+        // SynchronizationContext is preserved intentionally — callers may update UI state.
+        await first;


Let's make this explicit with ConfigureAwait(true).

Nuklon · 2026-04-23T16:42:29Z

+            {
+                await pending.ConfigureAwait(false);
+            }
+            catch (Exception)


Suggested change

catch (Exception)

catch

Nuklon · 2026-04-23T16:44:23Z

+            return Presenter.ImmediatelyDisplay(this);
        }
+
+        Presenter.AddToQue(this);


Can we rename this to AddToQueue?

Nuklon · 2026-04-23T16:45:05Z

+        }

-        await Task.Delay(300);
+        snackbarToHide.SetCurrentValue(Snackbar.IsShownProperty, false);


General comment here; we need to make sure we run these things on UI thread / through Dispatcher.

pomianowski added 2 commits April 23, 2026 16:27

feat: Migrate to SLNX

3f6cd92

feat!(threading): Add ValueTask

a4c0eeb

github-actions Bot added documentation Improvements or additions to documentation github_actions Pull requests that update GitHub Actions code PR Pull request gallery WPF UI Gallery dotnet release labels Apr 23, 2026

fix: Update declarations

c7bdb01

github-actions Bot added controls Changes to the appearance or logic of custom controls. navigation Changes to navigation related controls. labels Apr 23, 2026

fix: Update tasks

aa22b24

pomianowski changed the title ~~feat!(threading): Use ValueTask for async operations~~ feat!(threading): Use ValueTask for potentially synchronous operations Apr 23, 2026

pomianowski added 2 commits April 23, 2026 17:25

fix: Update content dialog

55dd471

fix: update content presenter

ef1ffac

pomianowski requested a review from Copilot April 23, 2026 15:53

Copilot started reviewing on behalf of pomianowski April 23, 2026 15:53 View session

pomianowski requested review from Nuklon and chucker April 23, 2026 15:54

Copilot AI reviewed Apr 23, 2026

View reviewed changes

pomianowski and others added 4 commits April 23, 2026 18:06

feat: Add Cancellation token

e111b6f

Update Directory.Packages.props

6004149

Update .github/workflows/wpf-ui-cd-extension.yaml

e6e9290

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

fix: Update content presenter

65bb9ea

Nuklon reviewed Apr 23, 2026

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feat!(threading): Use `ValueTask` for potentially synchronous operations#1693

feat!(threading): Use `ValueTask` for potentially synchronous operations#1693
pomianowski wants to merge 10 commits intomainfrom
feature/use-value-tasks

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		// NOTE: Post hide token, can we handle it better?
		await Task.Delay(300, cancellationToken);

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pomianowski commented Apr 23, 2026

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