MvvmAIO.Markup

XAML markup extensions for common CLR types (booleans, integers, Guid, DateTime, TimeSpan, decimal, double, enum, and more). The shared implementation ships in two NuGet packages: WPF and Avalonia.

Packages

Package	Description
MvvmAIO.Markup.WPF	WPF (UseWPF), multi-targeted from .NET Framework 4.6.1 through .NET 10 (Windows).
MvvmAIO.Markup.Avalonia	Avalonia 12, .NET 8 / 10.

Authors: MvvmAIO, Skymly, wys0610. License: MIT.

Installation

dotnet add package MvvmAIO.Markup.WPF
# or
dotnet add package MvvmAIO.Markup.Avalonia

Usage (WPF / Avalonia)

The library maps MvvmAIO.Markup into the default XAML namespace via XmlnsDefinition on xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml".

WPF

Use {x:…} markup extensions for all supported types (for example {x:Int32 42}, {x:True}, {x:Thickness 8}).

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Sample">
  <Button Content="Demo"
          CommandParameter="{x:Int32 42}"
          ToolTip="{x:Boolean True}" />
</Window>

Avalonia

Avalonia resolves CLR primitive names in the x namespace before custom {x:Int32 …} markup extensions. Use two patterns (both use the x prefix):

Kind	Syntax	Example
Built-in	{x:True}, {x:False}, {x:Null}, {x:Type …}	CommandParameter="{x:True}"
Platform extensions (this library)	{x:…} markup	CommandParameter="{x:Thickness 8}"
Shared CLR literals	Object elements (<x:Int32>…</x:Int32>, etc.)	See below
Enum / CultureInfo	x:EnumExtension / x:CultureInfoExtension with x:Arguments	See Samples.Avalonia

<Button Command="{Binding MyCommand}"
        CommandParameter="{x:Thickness 8}" />
<Button Command="{Binding MyCommand}">
  <Button.CommandParameter>
    <x:Int32>42</x:Int32>
  </Button.CommandParameter>
</Button>

Prefer Avalonia built-in {x:True} / {x:False} over {x:Boolean …} in attribute form.

Markup extensions

Extension	WPF	Avalonia	Notes
Boolean	✓	✓	WPF: {x:Boolean True}; Avalonia: <x:Boolean>True</x:Boolean> or built-in {x:True}
True	✓	✓	WPF: {x:True}; Avalonia: prefer built-in {x:True}
False	✓	✓	WPF: {x:False}; Avalonia: prefer built-in {x:False}
SByte, Byte, Int16, UInt16, Int32, UInt32, Int64, UInt64	✓	✓	WPF: {x:Int32 n}; Avalonia: <x:Int32>n</x:Int32>
Single, Double, Decimal	✓	✓	WPF: {x:…}; Avalonia: <x:…> object element
Char	✓	✓
Guid	✓	✓
DateTime, TimeSpan	✓	✓	Invariant culture parsing
String	✓	✓
Uri	✓	✓	Quote comma values in WPF {x:Uri '…'}
CultureInfo	✓	✓	WPF: {x:CultureInfo 'zh-CN'}; Avalonia: x:CultureInfoExtension + x:Arguments
Enum	✓	✓	WPF: {x:Enum {x:Type T},member}; Avalonia: x:EnumExtension + x:Arguments
Thickness	✓	✓	{x:Thickness 8} (both platforms)
Point, Size, Rect, Vector	✓	✓	Comma-separated — quote the value
GridLength, CornerRadius	✓	✓
Color	✓	✓	{x:Color '#FFFF0000'}
Duration, KeyTime	✓		WPF animation (System.Windows)

Null and booleans

Syntax	When to use
{x:Null}	Null reference for CommandParameter, attached properties, etc. (built-in XAML; not provided by this library).
{x:True} / {x:False}	Shorthand bool literals without a constructor argument.
{x:Boolean True}	Same CLR value as {x:True}, when you need the explicit Boolean extension form.

This library does not ship Nullable*Extension types — use {x:Null} for null.

Quoted constructor arguments

Values that contain commas (or other characters that break XAML tokenization) must be a single quoted argument:

CommandParameter="{x:Point '10,20'}"
CommandParameter="{x:Uri 'pack://application:,,,/Images/logo.png'}"

See Samples.WPF and Samples.Avalonia for full button matrices (WPF: all {x:…}; Avalonia: {x:…} + <x:…> elements).

Building & packing

• Solution: MvvmAIO.Markup.slnx
• Pack both NuGet packages: dotnet pack MvvmAIO.Markup.Pack/MvvmAIO.Markup.Pack.csproj -c Release
• Nuke (CI parity): dotnet run --project build/_build.csproj -- --target Ci --configuration Release

Contributing

Automated agents and contributors: see AGENTS.md (中文摘要), CONTRIBUTING.md, and CHANGELOG.md.

Repository

https://github.com/MvvmAIO/MvvmAIO.Markup