React Native Windows 0.78.0-preview.1

We're excited to release React Native Windows 0.78.0.preview1 targeting React Native 0.78.0-rc.0! There have been many changes to both react-native-windows and react-native itself, and we would love your feedback on anything that doesn't work as expected. This release includes the commits to React Native Windows from 12/18/2024 – 01/27/2025.

How to upgrade

You can view the changes made to the default new React Native Windows applications for C++ and C# using React Native Upgrade Helper. See this document for more details.

Reliability

• Add _DISABLE_CONSTEXPR_MUTEX_CONSTRUCTOR preprocessor definition to fix failing calls to std::mutex::lock. Fix calls to std::mutex::lock (#14223) · microsoft/react-native-windows@12a642f (github.com)
• Expand field sanitization to codedError.data. PRName (#14161) · microsoft/react-native-windows@42ff8f3 (github.com)
• Removes deprecated std::aligned_storage. std::aligned_storage is deprecated (#14253) · microsoft/react-native-windows@a8a7c00 (github.com)
• Stop disabling warning 4244 because BinSkim fails if it sees one. Stop disabling warning 4244 because BinSkim fails if it sees one (#14258) · microsoft/react-native-windows@5957d0a (github.com)
• Update the control type values of components to corresponding accessibilityRole value. Update the control type values of components to corresponding accessibilityRole value(#14215) · microsoft/react-native-windows@38f1cd0 (github.com)

New Features

• Updates WinUI3ExperimentalVersion from 1.6.240701003-experimental2 to 1.7.250109001-experimental2. Update WinUI3ExperimentalVersion from 1.6.240701003-experimental2 to 1.7.250109001-experimental2 (#14270) · microsoft/react-native-windows@a610c68 (github.com)
• Remove Paper-only code from Fabric builds of Microsoft.ReactNative. Remove Paper-only code from Fabric builds of Microsoft.ReactNative (#14289) · microsoft/react-native-windows@3cba4c4 (github.com)

New Architecture-specific changes

• Adds support for custom controls to pass range data to UIA via the IRangeValueProvider. Added support for aria-readonly and accessibilityState.readOnly. Implement IRangeValueProvider and Adjust IValueProvider Implementation (#14212) · microsoft/react-native-windows@7e4bcc6 (github.com)
• Rework modal to be implemented entirely using public APIs. Rework modal to be implemented entirely using public APIs(#14256) · microsoft/react-native-windows@fb5c92b (github.com)
• RNIsland UIA fragment root should report parents fragment root. RNIsland UIA fragment root should report parents fragment root (#14302) · microsoft/react-native-windows@b438707 (github.com)
• Fix crash when currently focused element gets marked as enableFocusRing=false. Fix crash when currently focused element gets marked as enableFocusRing=false (#14306) · microsoft/react-native-windows@47c5cd4 (github.com)