Here are the slides used in my NxtGen UK Mini-tour in May 2011

1. MonoTouch and
Mono for Android
with some Windows Phone 7
NxtGen User Group
Cambridge, Shenfield & Southampton
10th -12th May 2011
Chris Hardy

2. Chris Hardy
• ASPInsider
• Write some books
• http://twitter.com/chrisntr
• Work for great fridays

3. http://greatfridays.com

4. http://emmawatson.com

5. http://dominion-funds.com

6. Covering...
• How these technologies work
• Demos
• Similarities between MonoTouch and Mono
for Android
• Code Re-use with MonoTouch, Mono for
Android and Windows Phone 7

7. MonoTouch

8. What is Mono?
The .Net Framework
created by Miguel De Icaza
et al.

9. Miguel de Icaza

10. What is MonoTouch?
C# and .NET on the
iPhone

11. Demo - Walkthrough

12. Mono’s JIT Engine
Memory
Mono
CIL

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

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

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

16. MonoTouch’s APIs

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

19. 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);
}

20. MonoTouch Design
Integration
• Integrates with Interface Builder and Xcode
3
• Xcode 4 support coming

21. Demo - Integration

22. Learn to read Objective-C

23. 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...

24. 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

25. Binding against 3rd
party libraries
• https://github.com/chrisntr/monotouch-
bindings/tree/master/BingMaps
• Demo showing Bing iOS control in
MonoTouch

26. Who’s using
MonoTouch?
• Medtronic - http://www.apple.com/ipad/
business/profiles/medtronic/
• iCircuit - http://itunes.apple.com/us/app/
icircuit/id383359044?mt=8
• Showcase of apps - http://monotouch.net/
Apps/?tag=/Showcase

27. 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.

28. Demo
Twitter on iPhone with MonoTouch

29. What is Mono for
Android?

30. What is MonoDroid?
C# and .NET on
Android

31. Demo

32. How does MonoDroid
work?

33. What is MonoDroid?
Cross-platform

34. MonoDroid Features
• mandroid.exe
• Visual Studio 2010 Integration
• MonoDevelop MonoDroid Add-In
• Mono.Android.dll
• Full static AOT compiler and JIT support
• Support for all your existing code
• Reflection
• Generics
• LINQ
• Anonymous Methods
• Lambda’s etc...

35. What is MonoDroid?
v1.0 released in March
was expected late
2010...

36. What is MonoDroid?
Expect rapid releases a
la MonoTouch

37. What is MonoDroid?
A commercial product
same prices as
MonoTouch

38. What is MonoDroid?
Give feedback!
Submit bugs!
http://monodroid.net/

39. Mono for Android
book on its way!
Out around
July

40. Demo
Twitter on Android with MonoDroid

41. Similarities with
MonoTouch and
MonoDroid

42. Linker
and the application size...

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

44. Linking Assemblies

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

46. Same Base Class Libraries
More on this later...

47. Debugger
• MonoTouch/MonoDroid debugger
leverages Mono’s Soft-Debugger
• Supports the Simulator
• Supports the Device - on paid versions
• even over WiFi*

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

49. Minimum Compressed
MonoTouch App Size
~1MB
App-store Minimum
MonoTouch App Size
~4MB

50. Minimum MonoDroid
App Size (the .apk)
4.4MB
Compressed
2.2MB

51. Code reuse

52. Code reuse
Json.Net
FlickrNet
XNATouch (Now
MonoGame)

53. Rebuild your libraries
• Can’t just use any DLL
• Re-compile for each lib
• Each framework has its own class library

54. Portable Library
Project
will help

55. Not an abstraction!

56. Not an abstraction!
• Platform specific APIs
• Platform specific look and feel

57. Mono for WP7?

58. Mono for WP7?
• Look at Mono code and copy over!
• IQueryable support in WP7
• More later...

59. Porting over
Hanselminutes

60. Porting over
Hanselminutes
hanselminutesiphone.codeplex.com

61. Porting over
Hanselminutes
• Make sure your business logic is separate
• Use actions for returning results

62. Getting XML

63. Persisting the XML

64. Isolated Storage
vs
File Storage

65. Storing data
void SaveLocal(string data)
{
#if (MonoTouch || MonoDroid)
File.WriteAllText(_localPath, data);
#elif WINDOWS_PHONE
using (var appStorage =
IsolatedStorageFile.GetUserStoreForApplication())
{
var file = appStorage.OpenFile(_localPath, FileMode.Create);
FileExtension.WriteAllText(file, data);
}
#endif
}

66. Storing data
void SaveLocal(string data)
{
#if (MonoTouch || MonoDroid)
File.WriteAllText(_localPath, data);
#elif WINDOWS_PHONE
using (var appStorage =
IsolatedStorageFile.GetUserStoreForApplication())
{
var file = appStorage.OpenFile(_localPath, FileMode.Create);
FileExtension.WriteAllText(file, data);
}
#endif
}

67. No File.WriteAllText?
No problem!

68. Implementing
File.WriteAllText
public static void WriteAllText(IsolatedStorageFileStream fileStream, string data)
{
using (StreamWriter sw = new StreamWriter(fileStream))
{
sw.Write(data);
sw.Close();
}
}
public static void WriteAllText(string path, string contents)
{
WriteAllText(path, contents, Encoding.UTF8);
}
public static void WriteAllText(string path, string contents, Encoding encoding)
{
using (StreamWriter sw = new StreamWriter(path, false, encoding))
{
sw.Write(contents);
}
}

69. Mono Abstractions
With MonoMobile.Extensions in the future
https://github.com/chrisntr/MonoMobile.Extensions

70. Q +A
twitter.com/chrisntr
chrisntr@gmail.com