ONLY FOR TESTING: Integration-3 for the new .NET 11 API by KlausLoeffelmann · Pull Request #14768 · dotnet/winforms

KlausLoeffelmann · 2026-07-18T11:40:24Z

This branch is for integration testing only and must not be merged.

Component PRs: #14733, #14734, #14735, #14736, #14737
SystemVisualSettings proposal: KlausLoeffelmann#14

It combines the independently reviewed Net11 API branches B00 through B05 and adds the
cross-feature composition for:

SystemVisualSettings
VisualStylesMode change-impact dispatch
High Contrast routing
accent-aware rendering
client-area animation policy
TextBox focus metrics and text scale
the high-resolution animation pacer

The PR remains a draft validation surface for the complete .NET 11 API set.

The full CI matrix passes for Windows x86/x64/ARM64 in Debug and Release.

Microsoft Reviewers: Open in CodeFlow

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 27022e2a-9eb8-4f58-9bfa-e79ca0d6c559

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Hand-author the IUISettings3 / UIColor / UIColorType WinRT ABI types and generate the RoActivateInstance / WindowsCreateString / WindowsDeleteString / IInspectable / HSTRING Win32 bindings via CsWin32. The WinRT ABI types are excluded from the .NET Framework build, which does not consume them. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Expose the user's current Windows accent color by activating the Windows.UI.ViewManagement.UISettings runtime component and reading UIColorType.Accent. When no accent color is set, Windows returns an OS-defined default, so the method always yields a usable color. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Use event subscriptions as the opt-in for text-size notifications and remove the redundant awareness API surface. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 40d0f0f7-a584-4167-9187-9d529b7c70f8

Wrap the Form event remark in a paragraph and remove the redundant nullable handler initialization reported by the Arcade analyzers. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 40d0f0f7-a584-4167-9187-9d529b7c70f8

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 27022e2a-9eb8-4f58-9bfa-e79ca0d6c559

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 20883488-cf1e-4ad3-a681-0724e9f16777

…ce API.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Implements suspend painting and relocation scopes, deferred child positioning, and form appearance mode infrastructure for .NET 11. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…rface Splits DeferLocationChange out of this branch entirely (postponed pending an anchor-layout-engine integration fix; tracked separately in #12) and reworks ISupportSuspendPainting / ISupportSuspendRelocation on Control to match the final API shape agreed in dotnet#14585: - Control implements ISupportSuspendPainting/ISupportSuspendRelocation via explicit interface implementation instead of public virtual methods, so the manual Begin/End pair does not become the primary IntelliSense surface on every Control-derived type. Protected virtual BeginSuspendPaintingCore() / EndSuspendPaintingCore() / BeginSuspendRelocationCore() / EndSuspendRelocationCore() are the new override points. - ListView, ListBox, ComboBox, TreeView, RichTextBox override the ...Core() hooks instead of the old public virtual methods, still routing through their existing BeginUpdate/EndUpdate. - SuspendPaintingScope and SuspendRelocationScope change from readonly ref struct to sealed class : IDisposable, so the scope can span an await in an asynchronous UI event handler (a ref struct cannot be hoisted into an async state machine - this was the flagship usage scenario in the original API proposal, and it did not compile against the ref struct version). Dispose is idempotent. - Deletes DeferLocationChangeScope.cs and the Control.DeferLocationChange overloads entirely. - Updates/removes tests accordingly; updates PublicAPI.Unshipped.txt. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…inel Matches the final API shape agreed in dotnet#14585: - FormAppearanceMode -> FormRevealMode, adding Inherit = -1 as the ambient sentinel (Classic stays the CLR default value 0, matching the RightToLeft.Inherit / VisualStylesMode.Inherit precedent for ambient enums - the sentinel is a distinct value, not the zero value, so default(FormRevealMode) stays conservative). - Form.FormRevealMode is now a real public virtual, PropertyStore-backed, [AmbientValue(Inherit)] property (previously there was no per-Form property at all - only the flat, process-wide Application.FormAppearanceMode existed). This lets a form such as a splash screen opt itself out of deferred reveal without touching the process-wide default. Resolution is flat (Form only, no Control-parent-chain): DWM cloaking only ever applies to top-level, non-MDI-child windows, so there is no hierarchy to walk, unlike VisualStylesMode's genuine control-nesting cascade. - Application.FormAppearanceMode / SetFormAppearanceMode are replaced by three members: DefaultFormRevealMode (get; may return the unresolved Inherit sentinel, mirroring ColorMode returning the unresolved System value), SetDefaultFormRevealMode (freely reassignable, unlike the write-once SetDefaultVisualStylesMode - the effective default is derived in part from ColorMode/IsDarkModeEnabled, which are themselves mutable for the life of the process), and IsFormRevealDeferred (bool; the fully resolved answer: Deferred, or Inherit + IsDarkModeEnabled). This also fixes a compatibility problem in the original design: the old default was unconditionally Deferred whenever SetFormAppearanceMode was never called, an opt-out behavior change for every existing app; tying the Inherit resolution to dark mode means an app that never touches SystemColorMode sees no behavior change, while the scenario the feature exists for (dark-mode startup flash) is fixed by default. - ShouldUseDeferredAppearanceCloak now reads the resolved Form.FormRevealMode instead of the old flat Application-only check, so a per-Form override is actually honored. - Adds SR.resx/xlf entries for the new property's designer description. - Updates/adds tests; updates PublicAPI.Unshipped.txt. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Adds Microsoft.VisualBasic.ApplicationServices.ApplyApplicationDefaultsEventArgs.FormRevealMode, following the exact same pattern already established for ColorMode and HighDpiMode in that class, per dotnet#14585's API Proposal. WindowsFormsApplicationBase now carries a _formRevealMode shadow field (defaulting to FormRevealMode.Classic, matching the existing conservative default for _colorMode) and a protected FormRevealMode property, feeds it into the ApplyApplicationDefaultsEventArgs constructor alongside MinimumSplashScreenDisplayTime/HighDpiMode/ColorMode, reads back whatever the ApplyApplicationDefaults event handler set, and calls Application.SetDefaultFormRevealMode(_formRevealMode) at the end of OnInitialize alongside the existing Application.SetColorMode(_colorMode) call. This completes work anticipated but never finished in an earlier .NET 9 Visual Styles attempt at this same VB Application Framework extension point (OnInitialize already carried a comment claiming "We feed the defaults for HighDpiMode, ColorMode, VisualStylesMode to the EventArgs", but only HighDpiMode/ColorMode were ever actually wired up). Updates PublicAPI.Unshipped.txt for Microsoft.VisualBasic.Forms. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Apply disabled-text contrast to explicit foreground colors, paint rounded Classic popup corners over the real parent surface, and clip BackgroundImage content inside popup chrome and renderer content bounds. Follow-up for dotnet#14753 and dotnet#14760 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: c352332b-4b81-4492-bcfc-9dec524c27c9

Reapply explicit fullscreen bounds when display geometry or the taskbar working area changes so the normal-state kiosk window tracks the selected screen like the previous maximized window did. Fixes dotnet#14765 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: c352332b-4b81-4492-bcfc-9dec524c27c9

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

Move modern TextBox and UpDown chrome constants into a shared internal source so subsequent renderers use one DPI-independent metric family. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

Add mode-gated card, outline, and header-band renderers with shared layout metrics, cached scaled captions, text-scale relayout, and effective-mode UIA heading semantics. Keep FlatStyle.System native. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

Route Net11 Standard, Flat, and Popup styles through a DPI-aware WinForms adapter, share TextBox field metrics, align native selection heights, and round Win11 dropdowns while preserving System and High Contrast paths. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

Keep modern toggle switches owner-drawn when FlatStyle.System is selected and use control bounds instead of requesting an unsupported native adapter. Cover every FlatStyle, Appearance, and VisualStylesMode interaction. Fixes dotnet#14754 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

Base ShouldSerializeVisualStylesMode on the raw PropertyStore entry so Inherit emits no CodeDOM while explicit values round-trip through designer serialization. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

Move affected property contracts into partial declarations and add adaptive-layout guidance for metric growth, fixed-bounds editors, GroupBox content geometry, and aligned TextBox/ComboBox rows. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

Apply native selection-field height overrides only while modern metrics are active, or while restoring a field that previously used them, so classic owner-drawn item bounds remain unchanged. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

Assert the fixed non-owner-drawn mouse-over geometry instead of retaining the previous unsupported-adapter exception expectation. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

Render Standard as a borderless rectangular surface, use an accent outline for Flat and an accent header for Popup, and select real installed Semibold faces without mutating ambient fonts. Align caption and content metrics with Padding and preserve the existing visual-settings tracker cleanup. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

Reactivate designer serialization for the shipped Padding property, add a one-pixel framework inset, render rounded Standard and Popup frames plus a square Flat frame, and keep native edit/list content aligned across DPI, style, and layout changes. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

Accept the native System-style handle recreation's platform-dependent zero-or-one invalidation while retaining exact expectations for owner-drawn styles. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

Reintroduce the consolidated accessibility text-scale helper dropped during Integration-3 replay so SystemVisualSettingsTracker and font scaling share one registry implementation. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

LeafShi1 · 2026-07-20T03:32:19Z

+                    break;
+
+                case AnimationCycle.Bounce:
+                    item.FrameOffset = -item.FrameOffset;


item.FrameCount is only ever written, never read, and item.FrameOffset only feeds FrameCount — neither value is consumed by any rendering/progress logic ( progress is derived purely from timestamps). As a result the Loop and Bounce branches perform the same effective work (reset TargetTimestamp + RestartAnimation() ), so Bounce currently behaves identically to Loop and the "reverse direction" semantics are not implemented. On top of that, RestartAnimation() rebuilds the AnimationRendererItem , so the FrameOffset negation doesn't persist across cycles anyway. Is Bounce intended to be implemented later (i.e. these fields are placeholders), or can we drop FrameCount / FrameOffset and have Bounce fall back to the Loop path for now?

SimonZhao888 · 2026-07-21T05:47:30Z

+    public float NodeLeading
+    {
+        get => Properties.GetValueOrDefault(s_nodeLeadingProperty, 0.0f);
+        set


If NodeLeading is assigned a value greater than 0 but less than 1, the nodes in the TreeView become overly crowded, and overlapping issues occur. Should we round values within this range to avoid unexpected layout results?
Corresponding issue: #14791

ShouldUseDeferredAppearanceCloak() gated the DWM cloak on Visible == true, but it is only evaluated from OnHandleCreated, where a top-level form's window is still hidden (WS_VISIBLE is cleared from the create params and the show is deferred). The Visible state bit is not set until WM_SHOWWINDOW is processed, so the guard was always false, the cloak never engaged, and the window was shown uncloaked - still producing the default-background flash the mode is meant to prevent. Remove the Visible term so the already-hidden window is cloaked at handle creation. This covers Show, ShowDialog (which creates the handle via CreateControl before showing) and handle recreation. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

KlausLoeffelmann and others added 10 commits July 18, 2026 01:26

Centralize feature prompt documents

cb8e6bb

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 27022e2a-9eb8-4f58-9bfa-e79ca0d6c559

Add feature promp,

ba4b052

Factor system text scale lookup

904f907

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Add system text size APIs

e8ccfcc

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Add system text size tests

ea2837f

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Simplify system text size notifications

79a1bd1

Use event subscriptions as the opt-in for text-size notifications and remove the redundant awareness API surface. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 40d0f0f7-a584-4167-9187-9d529b7c70f8

Add system visual settings snapshot

a3b023e

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 27022e2a-9eb8-4f58-9bfa-e79ca0d6c559

KlausLoeffelmann added 🚫 * NO-MERGE * The PR is not ready for merge yet (see discussion for detailed reasons) draft draft PR labels Jul 18, 2026

dotnet-policy-service Bot assigned KlausLoeffelmann Jul 18, 2026

This was referenced Jul 18, 2026

Add SystemVisualSettings snapshot and notifications #14733

Open

Add versioned .NET 11 Visual Styles #14737

Open

KlausLoeffelmann and others added 10 commits July 19, 2026 23:43

Add TreeView.NodeLeading API

6f95d46

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Add TreeView.NodeLeading tests

7a0f1e8

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Cover NodeLeading DPI resynchronization

df6eb15

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 20883488-cf1e-4ad3-a681-0724e9f16777

Add the prompts for the new Suspend-Positioning-Painting-Form-Apearan…

39ce1d7

…ce API.

Add flicker-free mutation API proposal prompt

f7ebead

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Add flicker-free UI mutation APIs

efb62e0

Implements suspend painting and relocation scopes, deferred child positioning, and form appearance mode infrastructure for .NET 11. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Add tests for flicker-free mutation APIs

f0b430d

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

KlausLoeffelmann added 14 commits July 19, 2026 23:45

Add consolidated VisualStyles work order

74974bf

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 24d81626-c337-40c8-a515-393ee8e9827d

KlausLoeffelmann force-pushed the Net11/Integration-3 branch from 03d2028 to 175150e Compare July 20, 2026 06:45

Olina-Zhang mentioned this pull request Jul 20, 2026

[VisualStylesMode: Net11] GroupBox with FlatStyle = Popup/Flat displays an accent-colored header even when it is inactive #14774

Closed

Olina-Zhang mentioned this pull request Jul 20, 2026

DataGridViewComboBoxCell has multiple layout issues when entering edit mode #14782

Open

Zheng-Li01 mentioned this pull request Jul 20, 2026

[VisualStylesMode: Net11] The border line was interrupted for the ComboBox control when setting the RightToLeft as Yes in NET11 mode #14783

Closed

LeafShi1 reviewed Jul 20, 2026

View reviewed changes

Olina-Zhang mentioned this pull request Jul 21, 2026

[NodeLeading] TreeView row spacing collapses when NodeLeading is set between 0.0 and 1.0 #14791

Closed

SimonZhao888 reviewed Jul 21, 2026

View reviewed changes

This was referenced Jul 21, 2026

Text can get truncated in Combobox control in NET11 VisualStylesMode #14794

Open

Combobox controls still render in BackColor/ForeColor after setting Enabled to False in NET11 VisualStylesMode #14797

Open

ricardobossan mentioned this pull request Jul 21, 2026

[VisualStylesMode: Net11] ComboBox rounded corners leave background artifacts when the parent background is not a solid color #14799

Closed

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ONLY FOR TESTING: Integration-3 for the new .NET 11 API#14768

ONLY FOR TESTING: Integration-3 for the new .NET 11 API#14768
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