dotnet/wpf

Scancode not passed to TSF

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#11,635 opened on May 12, 2026

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Description

Description

The TextServiceManager does not pass scancode to Cicero/TSF

Reproduction Steps

https://github.com/dotnet/wpf/blob/7f005faa89e79b0b1fa1cb2c21283bab7916c092/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/TextServicesManager.cs#L232-L235

type anything using IME

Expected behavior

The scancode to be properly populated, e.g. from keyArgs.Scancode

Actual behavior

scancode seen in ITfKeyEventSink.On[Test]KeyDown is always 0

Regression?

no

Known Workarounds

reconstruct from virtual key

Impact

text services relying on scancodes do not work in WPF

Configuration

.NET 10/4.8, Windows 11, x64

Other information

No response

Contributor guide

Research direction
Inspect the TextServicesManager.OnKeyDown method and trace how keyPressArgs.Scancode is used or missing, then update the key event sink invocation to include scancode.
Tech stack
None
Domain
desktopapi
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
C#Windows API
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
65