Portable.Xaml is a fork of mono's System.Xaml converted to PCL and .NET Standard.

This is intended to be used to read and write Xaml on desktop, mobile, and .NET Core platforms.

Supported Profiles

Portable.Xaml currently supports the following profiles:

• .NET Standard 1.3 - For .NET 4.6.1, .NET Core, UWP, Xamarin, etc.
• Profile 259 - For .NET 4.5
• Profile 136 - For .NET 4.0

Other profiles can be contributed if desired, but these should support the widest range of platforms.

Downloads

The primary way to use Portable.Xaml is by adding the nuget package to your project.

To get daily builds, add the appveyor feed to your nuget package sources. Make sure you check 'include prerelease' to show the prerelease builds.

Goals

The goal of this library is not necessarily to replicate the functionality of System.Xaml going forward, so breaking changes may occur, but only when necessary to keep migrating to Portable.Xaml straightforward.

The main difference between this and System.Xaml is that it comes with its own (minimal) TypeConverter implementation for the PCL profiles as they do not support them. To hook into the existing System.ComponentModel.TypeConverter on platforms that support it, a shim can be added [to be documented].

Some of the enhanced functionality of Portable.Xaml include (but not limited to):

• Supports System.Collections.Immutable collections and dictionaries.
• Automatic support for immutable types (with no default constructor) without having to use x:Arguments by using properties flagged with ConstructorArgumentAttribute automatically.
• Easier to override ParameterInfo/PropertyInfo/MethodInfo/etc XamlMember creation from XamlSchemaContext
• TypeConverter is used for items when adding to any ICollection<T> inherited list, if the type does not match.

Project Status

While this library should be usable to read & write xaml files including markup extensions, it may have some bugs.

Contributors are more than welcome! Ideally this library can become well supported to bring xaml to more applications.

Performance

What about performance you ask? Portable.Xaml's performance has been drastically improved over mono's initial implementation, and is actually much faster than .NET's System.Xaml in most cases.

Here's some results using BenchmarkDotNet:

Load

Method	Mean	StdDev	Op/s	Scaled	Gen 0	Allocated
PortableXaml	569.8 us	16.294 us	1,754.9	1.00	11.7188	50.56 KB
SystemXaml	1,325.2 us	11.485 us	754.6	2.33	35.1563	151.53 KB
PortableXamlNoCache	1,409.3 us	7.649 us	709.6	2.48	25.3906	106.38 KB
SystemXamlNoCache	1,892.2 us	28.304 us	528.5	3.32	44.9219	184.67 KB
OmniXamlBenchmark	8,095.5 us	310.062 us	123.5	14.22	406.2500	1689.29 KB

Save

Method	Mean	StdDev	Op/s	Scaled	Gen 0	Allocated
PortableXaml	481.8 us	2.805 us	2,075.4	1.00	26.8555	110.4 KB
SystemXaml	809.2 us	12.997 us	1,235.8	1.68	28.3203	117.2 KB
PortableXamlNoCache	1,060.2 us	34.809 us	943.3	2.20	33.2031	138.91 KB
SystemXamlNoCache	1,151.5 us	18.052 us	868.5	2.39	33.2031	139.17 KB

License

Portable.Xaml is licensed under MIT.