XAML namespace (x:) language features (Windows Store apps using C#/VB/C++ and XAML)

x:Class attribute

Configures XAML compilation to join partial classes between markup and code-behind. The code partial class is defined in a separate code file, and the markup partial class is created by code generation during XAML compilation.

x:Key attribute

Uniquely identifies elements that are created and referenced as resources, and which exist within a ResourceDictionary.

x:Name attribute

Uniquely identifies object elements for access to the instantiated object from code-behind or general code. Once applied to a backing programming model, x:Name can be considered equivalent to the variable holding an object reference, as returned by a constructor.

x:Null markup extension

Specifies null as a value for a property being set through a XAML attribute.

x:Uid directive

Provides a unique identifier for markup elements. For Windows Runtime XAML, this unique identifier is used by XAML localization processes and tools, such as using resources from a .resw resource file.

XAML intrinsic data types

Lists language-level support in XAML for the Windows Runtime for certain data types in the common language runtime (CLR) and in other programming languages such as C++.