Understanding data binding in WinUI

In the previous chapter, you saw some simple examples of data binding, using both the Binding and x:Bind markup extensions. Let’s dissect some of the components that allow the View to receive updates when the View Model data changes.

What are markup extensions?

An in-depth discussion of markup extensions is beyond the scope of this introductory book. In brief, they are a class that executes some logic to return a value to the XAML parser. You can identify their use in XAML by looking for some markup inside curly braces. Take this example of Binding in the Text property of a TextBlock:

<TextBlock Text="{Binding Path=Name, Mode=TwoWay}"/>

From this, you can derive that there is a markup extension class named Binding and that two of its properties are Path and Mode. This markup extension takes these properties, resolves a value, and returns it to the XAML parser for display in the application’s View.

Some...