WPF in .NET 10 Preview 5 - Release Notes

June 10, 2025 ยท View on GitHub

Here's a summary of what's new in WPF in this preview release:

WPF updates in .NET 10:

XAML Grid Syntax Enhancements

This release introduces a new shorthand syntax for defining Grid.RowDefinitions and Grid.ColumnDefinitions in XAML, with full support for XAML Hot Reload.

Example:

<Grid RowDefinitions="Auto,*,Auto" ColumnDefinitions="*, Auto">
    <TextBlock Text="Row 0, Col 0" Grid.Row="0" Grid.Column="0" />
    <TextBlock Text="Row 1, Col 1" Grid.Row="1" Grid.Column="1" />
    <TextBlock Text="Row 2, Col 0" Grid.Row="2" Grid.Column="0" />
</Grid>

This shorthand allows you to specify row and column sizes directly in the RowDefinitions and ColumnDefinitions attributes, making XAML more concise and readable.

Font and Globalization Updates

The simsun-extg font has been added to improve character rendering, especially for East Asian languages.

Fluent Theme Improvements

Resolved crashes in the Fluent theme related to the TextBox control. Enhanced styling for SelectionBrush and Thumb controls, and improved visual accuracy by correcting the Expander arrow direction in right-to-left (RTL) layouts.

Performance and Code Quality Improvements

This release includes several improvements to performance and code quality:

  • Reduced memory allocations by replacing boxed collections such as ArrayList, Hashtable, and IList with more efficient alternatives like arrays and generic collections.
  • Optimized internal logic by refining parsing routines and removing unused fields in utilities such as DpiHelper and XamlSchema.
  • Eliminated the static constructor from KnownColors to improve runtime performance.
  • Removed legacy or unused code, including the ReflectionHelper for WinRT.