This document discusses using Xamarin.Forms to develop native mobile apps across platforms like iOS and Android more quickly and at lower cost than traditional Xamarin development. It provides examples of how UI elements like labels, pickers and list views can be coded once in Xamarin.Forms and rendered natively on each device. The document also shares examples of real apps developed in Xamarin.Forms that demonstrated high code reuse between platforms and significant time savings when migrating between iOS and Android. Resources for learning more about Xamarin.Forms development are provided.

1. Use Xamarin.Forms and surprise
your customers when develop
native apps, in less time and
cheaper
Paulo Ortins - @pauloortins – paulo.ortins@gmail.com

2. Founder at OnceDev
C# <3
Xamarin <3
People <3
Community <3

3. Xamarin Traditional

4. Xamarin Traditional
UI
Windows
Phone
UI
Android
UI
iOS
ViewModels
Services
Native APIs

5. API Natives Mirroring
Windows
Phone
Android
Text-to-speech
iOS
System.Net
System
System.IO
System.Xml
System.Linq
ActionBar
NFC
Printing
RenderScript
Microsoft.Phone
Windows.Networking
Windows.Storage
Windows.Foundation
Microsoft.Devices
MapKit
UIKit
iBeacon
CoreGraphics
CoreMotion

6. 3 classes - 1 component
TextBlockTextViewUILabel
TextBoxEditTextUITextField
ButtonButtonUIButton

7. It can be better…
TextBlockTextViewUILabel
TextBoxEditTextUITextField
ButtonButtonUIButton
Label
Entry
Button

8. Windows
Phone
Android
iOS
We need a Wrapper!
ÚNICO CÓDIGO

9. Xamarin.Forms

11. new ContentPage {
Content = new Label() {
VerticalOptions = LayoutOptions.Center,
HorizontalOptions = LayoutOptions.Center,
Text = ”Hello Florianópolis!"
}
};
Label

12. var picker = new Picker() {
VerticalOptions = LayoutOptions.Center,
HorizontalOptions = LayoutOptions.Center
};
picker.Items.Add ("Florianópolis");
picker.Items.Add ("São Paulo");
picker.Items.Add ("Porto Alegre");
picker.SelectedIndex = 0;
Picker

13. new ContentPage {
Content = new ListView() {
ItemsSource = new [] {"Salvador", "Florianópolis",
"São Paulo", "Brasília"}
}
};
ListView

14. Xamarin.Forms

15. Xamarin.Forms

16. How it works?
Core
Platform.iOS
Platform.Android
Platform.WP

17. How it works?
Label
LabelRenderer
LabelRenderer
LabelRenderer

18. Xamarin Traditional
UI
Windows
Phone
UI
Android
UI
iOS
ViewModels
Services
Native APIs

19. Xamarin.Forms
Windows
Phone
AndroidiOS
ViewModels
Services
Native APIs
UI

20. Demo: Xamarin.Forms

21. Real Apps

22. • App to display real-time data
from an ERP (Sales,
Expenses, Suppliers and so
on)
• A lot of graphs (line, pie and
bar) to display data
• 300h of development
(Backend e Mobile)
• 2 days to migrate from
Android to iOS

23. Conttroller Super Diretor
-
94%96%
Code
Sharing

24. • App to manage sales people
and enable them to create
orders from the app
• App should work both online
and offline (data
synchronization)
• 600h of development
(Backend e Mobile)
• 1 week to migrate from
Android to iOS

25. Conttroller Força de Vendas
-
93%95%
Code
Sharing

26. Forms x Traditional

27. How to start
• http://developer.xamarin.com/ - Official Site
• http://planet.xamarin.com/ - Xamarin Posts Aggregator
• www.pauloortins.com - My Blog
• www.syntaxismyui.com/ - Adam Wolf’s Blog
• http://developer.xamarin.com/guides/cross-platform/xamarin-
forms/creating-mobile-apps-xamarin-forms/ - Charles Petzold’s
Book
• http://www.xforms-kickstarter.com/ - Falko Schindler’s Book

28. Thank you!
paulocesar.ortinsbrito
@pauloortins
paulo.ortins@gmail.com