As you can see, the Text widget has no state information associated with it,
it renders what is passed in its constructors and nothing more.

But, what if you want to make “I Like Flutter” change dynamically,
for example, when clicking a FloatingActionButton?

To achieve this, wrap the Text widget in a StatefulWidget
and update it when the user clicks the button,
as shown in the following example:

How do I lay out my widgets? What is the equivalent of an XAML file?

In Xamarin.Forms, most developers write layouts in XAML,
though sometimes in C#.
In Flutter, you write your layouts with a widget tree in code.

The following example shows how to display a simple widget with padding:

You can view the layouts that Flutter has to offer in the
widget catalog.

How do I add or remove an Element from my layout?