Programming C# 5.0

Chapter 19. XAML

XAML (pronounced “zammel”) is a markup language for defining the layout and appearance of user interfaces. Several frameworks support it, so you can use XAML to create applications of the style introduced by Windows 8, but it’s also available for desktop and Windows Phone apps. There are various tools that can edit or process XAML. Visual Studio has a built-in XAML editor for designing user interfaces, and there’s also Microsoft’s Expression Blend, a standalone tool aimed more at designers and user interface integrators than developers, which has extensive XAML support.

The name XAML is supposedly an acronym for the eXtensible Application Markup Language, although as with many technical acronyms, Microsoft reportedly picked four letters that were more or less pronounceable and didn’t already have a widely accepted meaning, and then made up something plausible for them to stand for. In fact, for a while, the language was called Xaml (without the SCREAMING CAPS) and didn’t stand for anything, although Microsoft seems to have changed its mind since. This tells us that the name doesn’t reveal much, so what exactly is XAML?

XAML uses XML. One of the goals for XAML was to make it easy to write tools that support it, and Microsoft didn’t want to force people to write specialized parsers and generators just to be able to read and write the language. The XML namespace for XAML user interfaces defines various elements that correspond to interactive elements. Example 19-1 shows ...