Thanks to Geoff Norton and Miguel De Icaza for the basis of most of the slides. My MonoTouch session from the 5th UGIAlt.Net Conference in Milan on 23rd January 2010.

1. C# on the iPhone
with MonoTouch
Chris Hardy
@chrisntr

2. http://greatfridays.com

3. Covering...
• What is MonoTouch?
• How does it work?
• Why would you use it?
• Demos

4. Starting point....

5. Objective C and Xcode

6. Learn to read Objective-C

7. Learn to read Objective-C
• All Apple documentation is in Obj-C
• Most examples are in Obj-C
• It’s not too hard to understand
• It might even be fun...

8. What is MonoTouch?

9. What is Mono?

10. What is Mono?
Open Source .Net
Implementation of the
Microsoft .Net Framework

11. Mono’s JIT Engine
Memory
Mono
CIL

12. Apple No No...
• Contractual Requirements
• No interpreted code
• No shared libraries
• Kernel Limitations
• iPhone OS 2.0+ disables JIT

13. Mono’s AOT Engine
Native
Code
Mono
AOT Mono Runtime
CIL
ARM

14. Monotouch Features
• mtouch
• MonoDevelop iPhone Add-In
• CocoaTouch.NET
• Full static AOT compiler
• Support for all your existing code
• Reflection
• Generics
• LINQ
• Anonymous Methods
• Lambda’s etc...

15. MonoTouch’s APIs

16. The Bindings
• MonoTouch namespace
• MonoTouch.Foo namespace
• Maps to CocoaTouch’s Foo Framework
• 1:1 Mapping of classes.
• MonoTouch.UIKit.UILabel
• CocoaTouch’s UIKit framework, UILabel
class

17. Strong Types
• Objective-C
• Arrays are weakly typed:
• NSArray return values.
• MonoTouch has strong types
• UIView[] Subviews { get; }
• vs
• NSArray *subviews;
• Intellisense - explore the API...

18. Garbage Collection
• Automatic:
• Mono’s GC will collect objects on demand
• Deterministic:
• Use when you need control.
• Every object in MonoTouch implements IDisposable
using (var image = UIImage.FromFile(“foo.png”)){
surface.DrawImage(image, 20, 20);
}

19. Linker

20. What about App Size?
• 10 MB (compressed) limit on 3G/Edge
downloads
• .Net BCL and other libraries are huge
• Mono Linker to the rescue!

21. Linking Assemblies

22. Linker Options
• No Link
• Link SDK Only
• Full Link

23. Pipeline
• Interface Builder GUI Designer
• Exact same tool used by Xcode
• Support for existing Xcode interfaces
• MonoDevelop IDE

24. Integration
• Tight integration between MD and IB
• IB produces XIBs with MD parses
• Automatic class generation in MD
• Generates partial classes for all types,
outlets and actions defined in Interface
Builder

25. Outlets
• Instance Variables
• Can be strong or loosely typed
• MD will strong type

26. Actions
• Objects emit broadcast messages to
receivers
• You can do this C#
• MonoDevelop takes care of the details for
you
• Creates partial methods for you extend

27. MonoTouch Events
• Supports Objective-C pattern:
webView.Delegate = new
MyWebViewDelegate();
• C# style events as well:
webView.PageLoaded += delegate {
HideSpinningWheel();
}

28. Debugging
• Console.WriteLine(“Debugging inside of
MonoTouch”);
• printf(“I made it to this line!n”)

29. Well...
• MonoTouch released around 15th
September 2009
• MonoTouch 1.1 on 2nd October 2009
• MonoTouch 1.2 (Beta) released on 28th
October 2009... With Debugging support
• Currently on MonoTouch 1.4.5

30. Debugger
• MonoTouch debugger leverages Mono’s
new Soft-Debugger
• Supports the Simulator
• Supports the Device...
• even over WiFi

31. Debugger Features
• Breakpoints
• Catchpoints
• Inspection
• Watches
• Immediate / Expression Evaluator
• Call Stack
• Stepping

32. Caveats
• Debug binaries on devices are very large
• Cannot debug Main or FinishedLaunching
on device
• Consumes more memory runtime
• Performance hit

33. Getting started
• Get iPhone SDK from Apple
• Get Mono from Novell
• Get MonoTouch (evaluation version is free)
• Get MonoDevelop
• Register with Apple iPhone Developer
Program and purchase MonoTouch for
putting apps on device and AppStore.

34. Demo time...