Introducing XAML

XAML (which is the acronym of Extensible Application Markup Language) is a markup language based on XML to define the user interface of an application. The main difference compared to Windows Forms is that XAML enables a declarative approach to define a user interface, which makes it easier for a developer to interpret it just by looking at the code.

For example, consider the following UI:

Figure 2.1 – A simple WinUI application

This is how you describe it using XAML:

<Window>
    <StackPanel>
        <TextBlock>One</TextBlock>
        <TextBlock>Two</TextBlock>
        <TextBlock>Three</TextBlock>
    </StackPanel>
</Window>

Alternatively, this is how the same UI can be described using C#, as Windows Forms does...