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XmlnsDefinitionAttribute Class

Specifies a mapping in an assembly between an XML namespace and a CLR namespace. This class cannot be inherited.

Namespace:  System.Windows.Markup
Assembly:  WindowsBase (in WindowsBase.dll)

public final class XmlnsDefinitionAttribute extends Attribute
You cannot directly create an instance of this class in XAML.

The XML namespace can be used in a XAML markup file.

To find the appropriate types for an element and attributes in a XAML file, the XAML processor searches each referenced assembly for XmlnsDefinitionAttribute objects.

In a XAML file, if the xmlns attribute for an element tag or attribute matches the XmlNamespace in the XmlnsDefinitionAttribute, the XAML processor uses the ClrNamespace and AssemblyName stored in the XmlnsDefinitionAttribute instance to check if the element or attribute matches any type inside this namespace in the assembly.


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0