net9.0-windows10.0.22621 
namespace System.Xaml
{
    public static class XamlLanguage
    {
        public static IList<string> XmlNamespaces { get; }
    }
}
.NET 5.06.07.08.09.0
.NET Core 3.03.1
.NET Framework 4.04.54.5.14.5.24.64.6.14.6.24.74.7.14.7.24.84.8.1
Information specific to net9.0
Platforms This API is only available when you target a specific platform:
Windows 7.08.010.0.1776310.0.1836210.0.1904110.0.2034810.0.2200010.0.22621
Information specific to net9.0-windows10.0.22621
Assembly

System.Xaml , Version=9.0.0.0, PublicKeyToken=b77a5c561934e089

Referencing

Your project needs to set <UseWPF>True</UseWPF>.

Platform Restrictions

The property getter is only supported on the following platforms:

  • Windows
  • Built-in API
  • Package-provided API