Introduction talk for new mobile developers to Xamarin.Forms and how to leverage your C# skills to create mobile apps for iOS, Android and Windows Phone

1. Xamarin.Forms or
Write Once, Run
Anywhere
• Microsoft & Xamarin MVP
• @Tinytoot | www.tomwalker.codes
• Tom Walker

2. Meet Tom Walker | @Tinytoot
• Founder @LdnOntNetDevs | LondonNetDevelopers.ca
• Windows Platform Development MVP
• Xamarin MVP
• Developer for 15+ years now focusing on mobile and web frontend
– Worked with large enterprises, startups and software companies
– Design & build internal enterprise and consumer facing software

3. • Define the Problem
• What is Xamarin.Forms
• Explaining the parts
• Demo – BBQ Receipes
• Why I use Xamarin.Forms
Silo Approach

4. Define the Problem

5. Xamarin’s Unique Approach
• Native User Interface
• Native Performance
• Shared code across
platforms
• C# & .NET Framework
• Full API Coverage
With Xamarin.Forms:
more code-sharing, native controls
Shared UI Code

6. Explaining the parts

7. Content MasterDetail Navigation Tabbed Carousel
Pages

8. Stack Absolute Relative Grid ContentView ScrollView Frame
Layouts

9. ActivityIndicator BoxView Button DatePicker Editor
Entry Image Label ListView Map
OpenGLView Picker ProgressBar SearchBar Slider
Stepper TableView TimePicker WebView EntryCell
ImageCell SwitchCell TextCell ViewCell
Controls

10. Xamarin’s Xaml
The equivalent Xamarin XAML is:Consider this simple Microsoft
XAML example:

11. Databinding Basics

12. Platform Specific XAML

13. Global Styles
<Application xmlns=http://xamarin.com/schemas/2014/forms
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="WorkingWithAppResources.App">
<Application.Resources>
<ResourceDictionary>
<Style x:Key="labelStyle" TargetType="Label">
<Setter Property="TextColor" Value="Green" />
</Style>
</ResourceDictionary>
</Application.Resources>
</Application>
App.xaml

14. Let’s talk about Style
• Global Styles
• Built in Styles
• Behaviors
• Triggers

15. Built in Styles
There are built-in styles available in the Device.Styles class:
• BodyStyle
• CaptionStyle
• ListItemDetailTextStyle
• ListItemTextStyle
• SubtitleStyle
• TitleStyle

16. Built in Styles in C#
var mylabel = new Label {
Text = "This uses TitleStyle",
Style = Device.Styles.TitleStyle };

17. Built in Styles in XAML
<Label Text="This uses TitleStyle in XAML"
Style="{DynamicResource TitleStyle}"/>
<Label Text="This uses SubtitleStyle in XAML"
Style="{DynamicResource SubtitleStyle}"/>

18. Behaviors
<Entry Placeholder="Sample">
<Entry.Behaviors>
<local:SampleBehavior />
</Entry.Behaviors>
</Entry>
1. XAML 2. inherit from Behavior<T>
and override two methods
OnAttachedTo(Tview)
OnDetachingFrom(T view).
3. Write class behavior
public class SampleBehavior : Behavior
{
...
}

19. Triggers
<Entry Placeholder="enter name">
<Entry.Triggers>
<Trigger TargetType="Entry" Property="IsFocused" Value="True">
<Setter Property="BackgroundColor" Value="Yellow" />
</Trigger>
</Entry.Triggers>
</Entry>

20. Dependency Services
1. Interface 2. Implementation on platform
3. Calling in shared code
public interface ITextToSpeech
{
void Speak (string text);
}
[assembly: Xamarin.Forms.Dependency (typeof
(TextToSpeech_iOS))]
public class TextToSpeech_iOS : ITextToSpeech
{
public TextToSpeech_iOS () {}
public void Speak (string text)
{
speak.Clicked += (sender, e) => {
DependencyService.Get<ITextToSpeech>().Speak("Hello from Xamarin Forms");
};

21. Demo – BBQ time!

22. • C#
• XAML
• Rapid Prototyping
• Speed to Market
Why I use Xamarin.Forms

23. • Define the Problem
• What is Xamarin.Forms
• Explaining the parts
• Demo – BBQ Receipes
• Why I use Xamarin.Forms
Recap

24. Thanks you
Questions?
• Microsoft & Xamarin MVP
• @Tinytoot | www.tomwalker.codes
• Tom Walker