Chapter 4 An Architecture to Suit You

scheduler.ScheduleAction(

TimeSpan.FromSeconds(1), () =>

{

SetTime(DateTime.Now);

});

}

}

}

Now that you have added a load of code, let’s summarize what you have done.

Note that there are two common scenarios when an update is called: when there is user interaction (e.g., a click/tap of a button) and around asynchronous background work. Your example here applies to the second scenario.

XAML vs. C# Markup

XAML has proven to be a big part of building application UIs in Xamarin. Forms and it will likely continue in .NET MAUI, but I want to make it clear that you do not have to use it. So, if like some friends and colleagues, the verbosity of XAML makes you feel queasy, there is a solution!

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Anything that you can create in XAML can ultimately be created in C#. Furthermore, there are ways to improve on the readability of the C# required to build UIs.

Some benefits of building user interfaces solely with C# are

Let’s work through how you can build your ClockWidget in C# in all its verbosity and then I will show how you can simplify it using C# Markup. (I must add this is an open-source package that you need to bring in). Also, these examples are still built using MVVM.

Plain C#

As mentioned, anything you can build in XAML can also be built in C#. The following code shows how the exact same XAML definition of your ClockWidget can be built using just C#:

using WidgetBoard.ViewModels;

namespace WidgetBoard.Views;

public class ClockWidget : ContentView

{

public ClockWidget()

{

BindingContext = new ClockWidgetViewModel();

var label = new Label

{

FontSize = 80,

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HorizontalOptions = LayoutOptions.Center, VerticalOptions = LayoutOptions.Center

};

label.SetBinding(

Label.TextProperty,

nameof(ClockWidgetViewModel.Time));

Content = label;

}

}

The code above does the following things:

C# Markup

I have recently come to appreciate the value of being able to fluently build UIs. I don’t tend to do it often because I personally feel comfortable building with XAML or perhaps it is Stockholm Syndrome kicking in ☺ (I’ve been working with XAML for well over 10 years now). When I do, it needs to be as easy to read and build as possible given it is not something I do often.

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