Metro Style Apps are new type of applications are available in Windows 8 inside Metro User Interface.I knew that one can do that using programming language ( C# or VB.Net or C++) but a markup language called XAML is also needed. Perhaps it was the first time I heard about this new language. It is also needed if you want to program applications for Windows Phone 7 as well.
XAML, ( /ˈzæməl/) is a declarative XML-based language created by Microsoft and is used for initializing structured values and objects.For normal desktop applications XAML is used in a technology called WPF "Windows Presentation Foundation"
Due to Wikipedia defination WPF is a computer-software graphical subsystem for rendering user interfaces in Windows-based applications.As applied to the .NET Framework programming model, XAML simplifies creating a UI for a .NET Framework application. You can create visible UI elements in the declarative XAML markup, and then separate the UI definition from the run-time logic by using code-behind files, this code is joined to the markup through partial class definitions.
namespace WindowsPhoneApplication { public partial class MainPage: PhoneApplicationPage { // Constructor public MainPage() { InitializeComponent(); } } }XAML directly represents the instantiation of objects in a specific set of backing types defined in assemblies.
Note: This is unlike most other markup languages, which are typically an interpreted language without such a direct tie to a backing type system.
XAML enables a workflow where separate parties can work on the UI and the logic of an application, using potentially different tools.
Using XAML we can create objects like buttons, Text boxes, Radio Buttons, ....etc
For example to create a button we can do that through this code
<Button Background="Blue" Foreground="Red" Content="This is a button"/>