Defining a Label control

As a simple example, let's look at the following snippet of XAML:

<Label Text="Hello World!" />

When the XAML parser encounters this snippet, it will create an instance of a Label object and then set the properties of the object that correspond to the attributes in the XAML. This means that if we set a Text property in XAML, it will set the Text property on the instance of the Label object that is created. The XAML in the preceding example will have the same effect as the following:

var obj = new Label()
{
    Text = "Hello World!"
};

XAML exists to make it easier to view the object hierarchy that you need to create in order to make a GUI. An object model for a GUI is also hierarchical by design, so XAML has support for adding child objects. You can simply add them as child nodes, as follows: 

<StackLayout>
    <Label Text="Hello World" />
    <Entry Text="Ducks are us" />
</StackLayout>

The StackLayout is a container control that will organize the children vertically or horizontally within that container. A vertical organization is the default value, and will be used unless you specify otherwise. There are also a number of other containers, such as the Grid and the FlexLayout. These will be used in many of the projects in the following chapters.