React Native Windows: react-native-windows_v0.65.0-preview.1 Release

We're excited to release our first preview build of react-native-windows 0.65! 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.

What's New

• Hermes debugging and profiling: You can now debug and profile the heap-usage of your JavaScript code running on Hermes. See this document for details.

• New component capabilities: We've added Windows support for some existing, and some all new properties, including:

  • <Button>: tabIndex
  • <Pressable>: onKeyDown/onKeyUp
  • <TextInput>: autoFocus, clearTextOnSubmit, submitKeyEvents
  • <Image>: SVG data URI in source

• TraceLogging based ETW events: We now expose the ability to record ETW events for various framework actions. See Event Tracing in React Native for Windows for details.

• Hermes 0.8.0 with Improved Garbage Collector: Hermes 0.8.0 introduces The Hades Garbage Collector, which dramatically reduces GC pause times.

• More consistent styling for <Button>: The stock <Button> component has been updated with a look-and-feel consistent with other Windows controls.

• WinUI 2.5: We upgraded from WinUI 2.3 to WinUI 2.5, offering more refined native controls.

• FlatList performance improvements: Several performance issues causing excessive renders when using FlatList have been fixed.

• Opt-in fast builds: Set the RNW_FASTBUILD environment variable to true to enables building with larger PCH's. This leads to a much faster build, at the expense of higher system requirements to build successfully.

• IViewManagerCreateWithProperties: View managers may implement IViewManagerCreateWithProperties to receive properties at the time of view creation, simplifying cases where different properties may lead to different native views.

• Bug-fixes and improvements: The above just scratches the surface of the work that has been happening! We've been continually making bug fixes and improvements across the project.

Breaking Changes

• Legacy WebSocket implementation: We introduced a new WebSocket stack in 0.64, along with the QuirkSettings::SetUseLegacyWebSocketModule function to opt-out of it. This setting is now removed, and the new implementation is always used.

• 32-bit ARM support: We removed support for 32-bit ARM processors, which are used on some Windows IoT Core devices.

• WinUI 3 Islands: React Native Windows now targets WinUI 3 preview 4 when set to use WinUI 3. This requires changes for applications using WinUI 3 with XAML Islands.

How to upgrade

We've made it easier to upgrade to newer versions of react-native-windows!

While we are working to bring Windows support to React Native Upgrade Helper, you can see a diff explaining how to update your project using https://github.com/acoates-ms/rnw-diff. The below example shows the comparison between 0.63.0 and 0.64.0-preview.1:

<img src="https://user-images.githubusercontent.com/835219/119905046-4a286a80-bf00-11eb-89d7-7ee5a5a146f9.png" width=600>

During the preview period of 0.65 you will have to declare a dependency on [email protected] in your package.json file. When we release, this version will be replaced with react-native@^0.65.

...
"dependencies":  {
  "react-native": "0.0.0-7e05480cc"
}
...