Update .NET 11 desktop “What’s new” docs for Preview 4 (WPF + WinForms)

[Copilot]

Updates the .NET 11 desktop “What’s new” content for Preview 4 and aligns the .NET 11 article layout with net100.md (no per-preview subheadings in detail sections). WPF reflects no Preview 4 feature additions while retaining the existing bug-fix running list, and WinForms documents the Preview 4 clipboard bitmap retrieval fix with a round-trip snippet.

• WinForms: Preview 4 content refresh

  • Updated dotnet-desktop-guide/winforms/whats-new/net110.md metadata and heading to Preview 4.
  • Added Preview 4 release announcement link.
  • Documented the Clipboard.GetDataObject().GetImage() / DataObject.GetImage() bitmap fix.
  • Corrected behavior details to state that DataObject.GetImage uses typed pipeline retrieval (TryGetData<Image>(DataFormats.Bitmap, autoConvert: true, ...)) and returns null when retrieval fails.
  • Added API xrefs for Clipboard.GetDataObject, DataObject.GetImage, and Clipboard.GetImage.
  • Added the requested clipboard round-trip code snippet (including the Preview 4 round-trip comment).
  • Removed the obsolete Preview 3 No updates section now that Preview 4 includes updates.

• WPF: Preview 4 content refresh

  • Updated dotnet-desktop-guide/wpf/whats-new/net110.md metadata and heading to Preview 4.
  • Added Preview 4 release announcement link.
  • Preserved running-list content without per-preview detail subheadings or release-specific no-updates callouts.
  • Kept existing bug-fix details in the running list.

• Index updates

  • Updated Preview section/version text in:
    • dotnet-desktop-guide/winforms/whats-new/index.md
    • dotnet-desktop-guide/wpf/whats-new/index.md
  • WinForms index links to Preview 4 overview + bug-fix anchor.
  • WPF index links to Preview 4 overview.

---

Internal previews

📄 File	🔗 Preview link
dotnet-desktop-guide/winforms/whats-new/index.md	dotnet-desktop-guide/winforms/whats-new/index
dotnet-desktop-guide/winforms/whats-new/net110.md	dotnet-desktop-guide/winforms/whats-new/net110
dotnet-desktop-guide/wpf/whats-new/index.md	dotnet-desktop-guide/wpf/whats-new/index
dotnet-desktop-guide/wpf/whats-new/net110.md	dotnet-desktop-guide/wpf/whats-new/net110

[adegeo]

@copilot the updates in the .net 11 preview whats new articles are running lists, don't erase existing items. Also, here's code that now roundtrips for the winforms clipboard fix, add it:

// Round-trips again on .NET 11 Preview 4
Clipboard.SetImage(bitmap);
Image? image = Clipboard.GetDataObject()?.GetImage();

[Copilot]

@copilot the updates in the .net 11 preview whats new articles are running lists, don't erase existing items. Also, here's code that now roundtrips for the winforms clipboard fix, add it:

Updated. I restored the running-list entries in both .NET 11 preview articles and added the requested WinForms clipboard round-trip code snippet in net110.md. Addressed in commit 30d6716 (plus follow-up style refinements in f3b94a1).

[adegeo]

@copilot almost there. for styling and layout, check how net100.md is formed. No need to call out individual previews in the details.

[Copilot]

@copilot almost there. for styling and layout, check how net100.md is formed. No need to call out individual previews in the details.

Updated to match the net100.md layout: I removed per-preview subheadings from the detail sections and kept the running-list content in section prose. Addressed in commit 2ccf140 with follow-up wording/style refinements through 8444a62. Screenshot: N/A (docs-only change).

[Copilot]

@copilot the updates in the .net 11 preview whats new articles are running lists, don't erase existing items. Also, here's code that now roundtrips for the winforms clipboard fix, add it:

Updated in 960e232: the running-list content remains, and I added the requested round-trip snippet comment text. Screenshot: N/A (docs-only change).

@copilot almost there. for styling and layout, check how net100.md is formed. No need to call out individual previews in the details.

Adjusted to the net100.md-style layout in 7617dfd, with detail sections kept as running-list prose and no per-preview callout headings. Screenshot: N/A (docs-only change).

[Copilot]

Pull request overview

This PR updates the WPF and Windows Forms “What’s new” documentation for .NET 11 Preview 4, refreshes metadata and release-announcement links, and adjusts the index pages to point at the Preview 4 content.

Changes:

• Updated WPF and WinForms .NET 11 “What’s new” pages to Preview 4 (titles, dates, release announcement link, and wording).
• Added a WinForms Preview 4 bug-fix entry describing clipboard bitmap retrieval behavior and an example snippet.
• Updated WPF and WinForms “What’s new” index pages to reference .NET 11 Preview 4.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
dotnet-desktop-guide/wpf/whats-new/net110.md	Bumps WPF .NET 11 “What’s new” to Preview 4, adds Preview 4 release link, and refines bug-fix bullets.
dotnet-desktop-guide/wpf/whats-new/index.md	Updates index text to Preview 4 and adjusts the Preview section links.
dotnet-desktop-guide/winforms/whats-new/net110.md	Bumps WinForms .NET 11 “What’s new” to Preview 4, adds Preview 4 release link, and documents a clipboard bitmap retrieval fix with a snippet.
dotnet-desktop-guide/winforms/whats-new/index.md	Updates index text to Preview 4 and adds a link to the bug-fix section.

Comments suppressed due to low confidence (1)

dotnet-desktop-guide/winforms/whats-new/net110.md:37

• The snippet calls GetImage() on the result of Clipboard.GetDataObject(), but GetDataObject() returns IDataObject, which doesn't expose GetImage(). Update the example to use Clipboard.GetImage(), or cast the returned IDataObject to DataObject before calling GetImage().

  ```csharp
  // Round-trips again on .NET 11 Preview 4
  Clipboard.SetImage(bitmap);
  Image? image = Clipboard.GetDataObject()?.GetImage();

</details>

[wadepickett]

Approved. Assuming the few items alerady noted are being addressed.

Clipboard.GetDataObject returning bitmaps vs IDataObject fix suggested is important.