MonoTouch... CATiledLayer example (like DeepZoom/multi-scale-image)

UPDATE 2-Oct-02: Thanks to Miguel's assistance the NPhotoScroller code on github is now working!

The CORRECT port of this Objective-C snippet...

+ (Class)layerClass {
  return [CATiledLayer class];
}

...is this c# (requires using MonoTouch.ObjCRuntime;)

[Export ("layerClass")]
public static Class LayerClass () {
  return new Class (typeof (CATiledLayer));
}

and not the dodgy hack I came up with below...


Original Post:
Normally code posted on this blog actually works (or close to it...) but today I have a half-done port of an Objective-C sample that I just can't seem to finish off :-(

The idea was to port Apple's PhotoScroller sample, which demonstrates how to use the CATiledLayer, to MonoTouch.

The work-in-progress is on github: NPhotoScroller*... however it isn't quite finished and I'm hoping someone will point out what is missing.

If you download the sample (and grab the images from Apple), the my MonoTouch port looks like this:

It seems to be working, since the image is being successfully drawn using tiles BUT there are too many tiles for this zoom level. It should look like the image below (ie. 4 tiles) but I can only get that effect by hardcoding TilingView.cs::line 96 to a specific zoom level of 0.125

Using a different hardcoded zoom level of 0.25 results in this output, so the tiles are 'definitely kinda working'...

The problem? Zooming is totally broken - any attempt to pinch/zoom on these images breaks. TilingView.cs::line 95 ALWAYS returns a scale of 1 - it never changes. ImageScrollView.cs::line 157 this.ZoomScale = this.MinimumZoomScale seems to have no effect: no matter what the MinimumZoomScale is (eg. 0.08), ZoomScale is always 1 and the context.GetCTM() CGAffineTransform never reflects a change in zoom level.

If you switch from 'tiled' to 'whole' images (PhotoViewController.cs::line 63 useTiledImage = false;) then zooming works perfectly (if greedily from a memory perspective). I would love to hear any suggestions!!

Aside: I did have one minor issue with the port... what to do with this code in TilingView.m


+ (Class)layerClass {
return [CATiledLayer class];
}


It's been ported as the following in TilingView.cs but I could be way off base...


private CATiledLayer __layer;
public override CALayer Layer {get
{ // set in ctor
return __layer;
}
}


...HELP?!

* NOTE: If you download the sample from github, you MUST also download Apple's original sample to get their test image files.

MonoTouch meet WindowsPhone7

This is a very basic example of how you can share data and code between the iPhone platform (using MonoTouch) and recently RTM'd Windows Phone 7.

The code is available on github... notice that the source data (restaurants.xml file) and class file (Objects.cs) are identical on both platforms, as is the XmlSerialization code that parses the data into memory for display.

You will see there is a lot more 'user code' in the MonoTouch project for iPhone - this is due to the laborious way that UITableViews must be coded*; whereas the WP7's Silverlight heritage allows some very neat databinding scenarios.

* the excellent MonoTouch.Dialog project significantly reduces this code overhead on MonoTouch - definitely give it a try!

...now I just need to put the MonoDroid version together... :-)

UIGlassButton Generator in MonoTouch

Sometimes the default look of iOS controls (such as UIButton) is a little 'flat'. Apple themselves sometimes use a very pretty 'glass button' effect, which could be achieved (apparently, I'm paraphrasing here) using an undocumented UIGlassButton class. You can read more about this in the source links for this sample:

• MonoTouch tips and snippets, which points to...
• Martin Bowling's MTGlassButton (ZIP file), which seems related to...
• Erica Sudan's Shiny buttons devsugar, which uses...
• @schwa (Jonathan Wight)'s Objective-C version

Anyway... Martin did a great job porting this approach to MonoTouch, creating a GlassButton.dll wrapper as part of a sample project that allows you to create great-looking PNG-image-glass-buttons to incorporate into your iOS projects. The only thing missing was a double-resolution version for my new iPhone4's Retina Display, so that's what I've added to this github project: GlassButtonGenerator.

How it works:

1. Edit the string constants for button text and filename
2. Edit the filename which is used in the path to save the output
3. Run the app in the Simulator and press the [Generate Glass Button] button
4. Grab the images that are saved to your Desktop
5. Use the images in your iOS app in UIButton controls

Here is the 'output' when you are running it in the simulator (the button images should be saved to your Desktop):

If you are then wondering what to do with the two images, check out Miguel's post on Building apps for the Retina Display. Basically you should use UIImage.FromBundle to load the image and ensure that the 'regular' and 'retina' versions have the same filename (with the 'retina' version having a suffix @2x).

For the code below, the /Images/ folder has four images: BuyGlass.png, BuyGlass@2x.png, CancelGlass.png, CancelGlass@2x.png (where the @2x images have double the height & width dimensions of the base image)...

buyButton.SetImage(
     UIImage.FromBundle("Images/BuyGlass.png")
   , UIControlState.Normal);
cancelButton.SetImage(
     UIImage.FromBundle("Images/CancelGlass.png")
   , UIControlState.Normal);

Don't forget to make the Build Action: Content for your image files! And remember, DON'T use UIGlassButton in your apps directly - generate the images and include them.

UPDATE (May 2011): Miguel has posted a code-based glass button implementation which you might prefer to this pre-generated image one. See Glass button for iPhone and the code on github.

Drawing on Maps with MonoTouch

iOS4 introduced new features like MKOverlay to help draw lines/routes and shapes/polygons on the MKMapView control, however it has always been possible to add these features to maps in iOS3.

Two (Objective-C) examples of displaying geometric shapes on MKMapView in iOS3 are:

• Drawing polyines or routes on a MKMapView by Craig Spitzkoff, which shows how to draw a line on a map from a file of latitude/longitude points.
• Drawing a Point, Line, Polygon on top of MKMapview by Rupert, which builds on the previous example to allow drawing your own lines/polygons on a map.

...it is these examples that I've ported to MonoTouch (as a Universal app: iPhone and iPad). You can grab the code from github project MapStuff and see some screenshots below:

I put together a class diagram to try and explain how they work (the classes shown are from the 2nd example, which allows you to draw your own shape).

Please remember all the hard work here has been done by the original authors. All credit goes to them. Any bugs in the MonoTouch code are mine... let me know if you find any.

iOS4 examples to follow...

More MonoTouch Machine-translation Madness!

In addition to the recent dodgy Spanish localization, my TweetStation fork now has dodgy French, Japanese, German and Italian translations (courtesy of the Microsoft Translator API that was introduced at MIX10). Here's how they look:

The following two code snippets were added to ngenstrings so that once the text has been extracted from TweetStation, it is automatically translated and written to .strings files ready for inclusion in the correctly-named .lproj folders (this code hasn't been committed to github - but it should be easy to add to your local copy).

add code to the end of MainClass.Main

string[] languages = new string[]{"fr","ja","it","de"};
foreach (var language in languages)
{
   foreach (var table in tables.Values)
   {
      foreach (LocalizedString locstring in table.Values)
      {
         locstring.Value = Translate(locstring.Key, language);
      }
      table.WriteStringsFile(assemblyName, outputFormat, language);
   }
}

add method to MainClass

//http://msdn.microsoft.com/en-us/library/ff512421.aspx
static string Translate (string text, string toLanguageCode)
{
   string appId = "REGISTER_AND_INSERT_YOUR_APPID";
   string translation = text;
   text = text.Replace(" ", "%20").Replace("&", "").Replace("#","%3F");

   string detectUri = "http://api.microsofttranslator.com/v2/Http.svc/Translate?appId=" + appId +
  "&text=" + text + "&from=en&to=" + toLanguageCode;
   Console.WriteLine(detectUri);
   try {
      System.Net.HttpWebRequest httpWebRequest = (System.Net.HttpWebRequest)System.Net.WebRequest.Create(detectUri);
      System.Net.WebResponse resp = httpWebRequest.GetResponse();
      Stream strm = resp.GetResponseStream();
      StreamReader reader = new System.IO.StreamReader(strm);
      translation = reader.ReadToEnd();
   }
   catch (Exception e)
   {
      Console.Write("Translation failed for " + text + " - " + e.Message);
   }
   return translation;
}

Hopefully that gives you some ideas (or inspiration) on how to increase the market for your apps across the world. Remember that machine-translation is NOT a substitute for a professional human translation, however it can be useful to test your application's ability to handle and display different languages (eg. the size of the strings, etc).

TwitEstaçion: MonoTouch TweetStation en español

If you are a MonoTouch developer then you should already be familiar with the two subjects of this post:

• Miguel's awesome TweetStation open-source/MonoTouch Twitter client (also on iTunes); and
• the recent release of the Professional iPhone Development with MonoTouch/c# book from Wrox

It just so happens that Chapter 12 - Localizing for an International Audience of the book introduces a small utility called ngenstrings that helps you to translate your application into other languages. Today I updated ngenstrings to use the latest Mono.Cecil version, and to test it out I decided to have a go at localizing TweetStation into Spanish. You can download the Localizable.strings file that was created (and translated courtesy of Bing). Here's a screenshot showing where it fits into the solution:

...and here are a couple of screenshots showing TwitEstaçion in action ;-)

NOTE: Miguel had already made a good start building an internationalized app - many of his strings were wrapped in a Locale.GetText() method which was easy for me to work with. None of his code needed to change except for Locale.Get() and Locale.Format() to add NSBundle.MainBundle.LocalizedString(str,"");
NOTE2: this was a MACHINE TRANSLATION - of course you would arrange for a real person to translate your apps before taking them to the AppStore!
NOTE3: I have not translated 100% of Miguel's app - this is for demonstration purposes at the moment.
NOTE4: It's called TwitEstaçion because "TweetEstaçion" is too long for the iPhone home screen, and gets shortened unreadably. I don't speak Spanish so who knows if that makes any sense at all!

UPDATE: a few more screenshots... (again, apologies for the machine translation:)

UPDATE2: localized code forked from TweetStation main now available on github.

MonoTouch port of TDBadgedCell

I recently wanted to add an 'item count' to a UITableView in one of my iPhone/iPad projects and thought it would be nice to match the grey/encircled 'badge' used in the Mail application.

Happily,  I found (via The Unofficial Apple Weblog) that Tim Davies had the same idea and already done the hard work, albeit in Objective-C. Tim's code for TDBadgedCell is on github (you can help him out and donate, too), as is the MonoTouch/C# port: TDBadgedCellSharp. Both produce the same output (shown below)

The important stuff (TDBadgeView and TDBadgeCell) is in TDBadgedCell.cs - the rest of the project is purely for demonstration purposes.

Here's a very simple example of how to use the badged cell (warning: doesn't show DequeueReusableCell which you would normally use in the GetCell method)...

public override UITableViewCell GetCell 
   (UITableView tableView, NSIndexPath indexPath)
{
   TDBadgedCell cell = new TDBadgedCell (UITableViewCellStyle.Subtitle, "Cell");
   cell.TextLabel.Text = contents[indexPath.Row].Title;
   cell.TextLabel.Font = UIFont.BoldSystemFontOfSize (14);

   cell.DetailTextLabel.Text = contents[indexPath.Row].Detail;
   cell.DetailTextLabel.Font = UIFont.SystemFontOfSize (13);

   cell.Accessory = UITableViewCellAccessory.DisclosureIndicator;
   cell.BadgeNumber = Convert.ToInt32 (contents[indexPath.Row].Badge);

   if (indexPath.Row == 1)
      cell.BadgeColor = UIColor.FromRGBA (1.000f, 0.397f, 0.419f, 1.000f);
   if (indexPath.Row == 2)
      cell.BadgeColor = UIColor.FromWhiteAlpha (0.783f, 1.000f);
   return cell;
}

Thanks Tim!

..and finally, if you didn't notice the cover at the top of this page or seen the tweets, "my" book (and Wally, Chris, Martin & Rory's :) is now available from Amazon (and other locations, in paper or PDF)!

iPad 'infinite scrolling' with MonoTouch

Tonights exercise proves that sometimes it's worth taking time out to 'design' a chunk of code before writing it. Here's the "design"... can you see what it's trying to do?


Okay, I'll tell you: I'm trying to create an 'infinite' (well, just a configurable number) of scrollable pages that are rendered with UIWebView controls. I want to use the minimum number of controls for performance and memory but I also want a nice scrolling experience where the next and previous pages are aways pre-loaded. As you scroll left and right, the UIWebViews are shuffled around (X-coordinates only) to create an effect similar to the Time magazine 'app'.

Amazingly it worked out pretty quickly - here are a couple of screens to "prove" that it scrolls left & right as expected. It's using a "CSS3" multi-column hack in the Html, but that's another story...


And here are the 'important bits' of the code. I'm not publishing the entire source right now - the app still has a long way to go - but you get the idea... I hope. I only had a brief look around for existing examples so if you've seen a better one, let me know!

// declarations
UIScrollView MyScrollView;
UIWebView[] WebViewArray = new UIWebView[3];
int[] WebViewHasPage = new int[]{0,1,2};
int NumberOfPages = 8; // news01.html .. news08.html
...
// ViewController ctor
var bounds = new RectangleF(0, 0, View.Bounds.Width, View.Bounds.Height);
MyScrollView = new UIScrollView(bounds);
RectangleF scrollFrame = MyScrollView.Frame; // start with screen size
scrollFrame.Width = PageWidth * NumberOfPages; // then make the content
MyScrollView.ContentSize = scrollFrame.Size; // 8 screens wide
MyScrollView.Scrolled += ScrollViewScrolled; // and attach event handler
for (int i = 0; i < 3; i++)
{ // lay out three web controls to shuffle around
 webViewFrame.X = PageWidth * i;
 WebViewArray[i] = new UIWebView(webViewFrame);
 WebViewArray[i].ScalesPageToFit = false;
 var u = NSUrl.FromFilename(basedir+"news0"+(i+1)+".html");
 var r = new NSUrlRequest(u);
 WebViewArray[i].LoadRequest(r);
 MyScrollView.AddSubview (WebViewArray[i]);
}
...
// and the method that does the shuffling
private void ScrollViewScrolled (object sender, EventArgs e)
{
 UIScrollView sv = (UIScrollView)sender;
 double page = Math.Floor ((sv.ContentOffset.X - sv.Frame.Width / 2) / sv.Frame.Width) + 1;
 int LastPage = CurrentPage;
 int NewPage = CurrentPage;
 if (sv.ContentOffset.X % PageWidth == 0) NewPage = (int)page; // moved pages!
 if (NewPage >= 0 && NewPage < NumberOfPages)
 {
  pageControl.CurrentPage = NewPage;
  CurrentPage = NewPage;
  int updatePage = 0;
  bool shouldMove = false;
  if (NewPage > LastPage)
  {// moving right
   updatePage = NewPage + 1; shouldMove = true;
  }
  else if (NewPage < LastPage)
  {// moving left 
   updatePage = CurrentPage - 1; shouldMove = true;
  }
  if (shouldMove & (updatePage >= 0) & (updatePage < NumberOfPages))
  {
   int webViewSlot = updatePage % 3; 
   if (WebViewHasPage[webViewSlot] == updatePage) return; // already has it
   else WebViewHasPage[webViewSlot] = updatePage;
   var url = NSUrl.FromFilename(BaseDirectory+"news0"+(updatePage+1)+".html");
   var request = new NSUrlRequest(url);
   WebViewArray[webViewSlot].LoadRequest(request);
   var rect = new RectangleF (
      WebViewArray[0].Frame.Width * updatePage
    , WebViewArray[webViewSlot].Frame.Y
    , WebViewArray[webViewSlot].Frame.Width
    , WebViewArray[webViewSlot].Frame.Height);
   WebViewArray[webViewSlot].Frame = rect;
  }
 }
 else
 {
  Console.WriteLine ("Scrolled a little too far, to page " + page);
 }
}

Anatomy of a c# iPhone app (with MonoTouch)

Wow - it has been a long time since my last post... and with good reason ;)

Firstly I've been busily writing (along with Wally, Chris, Martin & Rory) for Wrox' upcoming Professional iPhone Programming with MonoTouch and .NET/C# which is available for pre-order on Amazon. If you are interested in developing for the iPhone using C# and the .NET Framework it should be a great addition to all the resources already out there on the web.


Secondly I've been working on an iPhone app for MIX10 in Las Vegas next week (with help from Chris, Miguel & Geoff). Whether you are heading to MIX or just curious about C# and MonoTouch on the iPhone, why not download and give it a try?

Since the MIX10.app was first 'announced' on twitter #MIX10 there have been a number of requests for the source code. Unfortunately the source isn't public at the moment, however that doesn't mean we can't talk about "how it works". To start with, the MIX10.app is based on two previous iPhone apps written in C# with MonoTouch, and whose source code is available:

• Monospace09 code is on github and is discussed on my blog (and here)
• PDC09 is on github and discussed in this post

If you have an Intel Mac (with Snow Leopard) then you can download both the Apple SDK and the MonoTouch trial version for free and get both these C# .NET examples running in the iPhone Simulator for yourself. To deploy on a real iPhone requires certificates and licences (from Apple and Novell/MonoTouch respectively).

MIX10.app
Here's the overall class diagram for the MIX10.app (with the views shown too). Even without seeing the code it's clear that the classes themselves are not overly complex (ie. few methods are required; and inheritance can be leveraged to share common functionality).


The MIX10.app also uses Miguel's MonoTouch.Dialog framwork and he's posted a snippet of code on gist.github which is responsible for this screen (on the left)




And he also posted this code which creates the 'My Schedule' view on the right. Pretty neat use of Linq, eh? I'm not sure I've seen such an expressive user-interface expressed in so few lines of code before...

public class FavoritesViewController : DialogViewController {
  public FavoritesViewController () : base (null) { }
  public override void ViewWillAppear (bool animated)
  {
    var favs = AppDelegate.UserData.GetFavoriteCodes();
    Root = new RootElement ("Favorites") {
      from s in AppDelegate.ConferenceData.Sessions
        where favs.Contains(s.Code)
        group s by s.Start into g
        orderby g.Key
        select new Section (MakeCaption ("", g.Key)) {
          from hs in g
            select (Element) new SessionElement (hs)
        }
    };
  }
}

The object model closely follows the data available from the api.visitmix.com site's OData and RSS feeds. These are plain vanilla C# objects which also run on the server to download and package the data for the iPhone - the object graph is serialized by a .NET application on Windows Server 2003, downloaded by the WebClient class on the iPhone (thanks to MonoTouch) and de-serialized ready for display. A perfect example of the cross-platform possibilities facilitated by MonoTouch and having the .NET framework available on both server and mobile device.


Finally, here's a quick overview of ALL the screens in the app.


...and if you're a Windows Phone Series 7 fan-in-the-making, it should be obvious that having a shared set of services and functionality in C# that can be deployed across iPhones with MonoTouch, and Silverlight/Windows Phone 7 with only UI code needing to be customized is a great way to achieve maximum reach for your apps. The MonoTouch Roadmap is also targetting a Q3 release of MonoDroid, so with a bit of imagination it isn't hard to see where the future of cross-mobile-device development is heading...

MonoTouch MapKit.Delegate-precated

An update to MonoTouch (1.4.4) was released today with these changes/improvements (actually 1.4.5 was released a day later). One in particular caught my eye, since I've previously blogged about MapKit in MonoTouch.

MKMapView now has C# style events

So what does that mean? Basically the crafty team at Novell have turned the Apple SDK "pattern" of using a MKMapViewDelegate class to respond to "events" on its head, and instead exposed familiar .NET events on MKMapView itself. *

Here's a comparison of the 'old' and 'new' MKMapView class:


Here are two 'example' delegate methods that work in 1.4.4 (and .5). Firstly here's an example of wiring up one of the "new" events CalloutAccessoryControlTapped. NOTE the += used to attach the delegate to the event.

Map.CalloutAccessoryControlTapped += 
      delegate(object sender, MKMapViewAccessoryTappedEventArgs e)
{
   MyAnnotation myAnn = e.View.Annotation as MyAnnotation;
   using (var alert = new UIAlertView (myAnn.Title,
     myAnn.Subtitle + " clicked", null, "OK", null))
   {
      alert.Show();
   }
};

The second example is probably the most common one - GetViewForAnnotation - which you will need to provide if you want to do any sort of customization of your pins/callouts. NOTE how it is assigned with an equals sign and has a return value!

Map.GetViewForAnnotation = delegate (MKMapView mapView, NSObject annotation) {
   if (annotation is MKUserLocation) return null;
   MyAnnotation myAnn = annotation as MyAnnotation;
   var annView = mapView.DequeueReusableAnnotation ("pin");
   if (annView == null) {
      var pinView = new MKPinAnnotationView(myAnn, "pin");
      pinView.AnimatesDrop = true;
      pinView.CanShowCallout = true;
      annView = pinView;
   }
   else 
   {
     annView.Annotation = annotation;
   }
   return annView;
};

* imagine these are "air quotes" in this paragraph
p.s. This post has been updated since the comments below. The first two kinda don't make sense now... Thanks for the advice mdi.

Moonlight 2.0...

Decided it was time to take another look at Moonlight (since 2.0 was released on 17-Dec-09), so I grabbed a Virtual PC image download and within a few minutes was testing my existing Silverlight sites on Linux! The pre-installed software (Firefox, Moonlight, even MonoDevelop) makes 'getting started' super-easy.

Happily, RaceReplay.net works fine -- although it uses the 'CTP' of Microsoft's Map control - the RTW requires SL3 which might throw a spanner in the works :-(

The DeepEarth open-source DeepZoom-based map control does work, however, which is great.

Searcharoo's Silverlight UI breaks with Could not load type 'BufferedStreamReader' from assembly System.Json so I'll have to investigate that; might have to get a different Json lib.

Anyway, IMO Moonlight 2.0 is a great achievement by Novell and the VPC is a great way for .NET developers to learn about it... have fun!

iPhone Obj-C books for MonoTouch devs (first look)

UPDATE 6-JUN-10:This book Professional iPhone Programming with MonoTouch and .NET/C# is available for pre-order on Amazon... one of the authors might be familiar :-)

UPDATE 2-DEC-09: the first MonoTouch-specific book (that I know of) is now available to purchase/download - Building iPhone and iPod touch Applications for the .NET/C# Developer with MonoTouch (Wrox Blox). I haven't had a chance to read closely yet, but it's good value at USD6.99 so definitely worth a look.

I recently received yet another addition to my 'Objective-C books for iPhone Development' collection - initially started to learn Obj-C (never happened) they are now more of a reference while learning MonoTouch.

Firstly, I have NOT read them cover-to-cover... I've done a bit of flicking, a bit of skimming and read a chapter or two. Secondly, I'm not really evaluating them according to their original purpose - to teach Objective-C - rather I'm making a personal judgement on their suitability as reference material for .NET developers.

I've listed them in their "order of usefulness" for MonoTouch .NET devs (according to me :)

Beginning iPhone Development: Exploring the iPhone SDK [BEGINNING IPHONE DEV]
Dave Mark; Jeff LaMarche (APress)

This was the first iPhone book I purchased, so I've read it more closely than the rest. I learned quite a bit from various examples and discussions in this book - it's probably at the top of the list for this reason. The writing style is easy to read and there isn't too much emphasis on Xcode (other books do seem to focus on Xcode, the Head First one most heavily).

The initial chapters are probably best replaced with a MonoTouch 'Hello World' screencast - you don't really need to know all the Xcode, pch files and @synthesize that the book discusses (and there are quite a few free resources around that cover "your first MonoTouch app").

Pros
• Interface Builder examples are relevant
• Friendly colloquial tone
• Widest variety of topics (includes localization, accelerometer)

Cons
• Large swaths of Objective-C in some chapters
• Still need to decode Objective-C in the examples

Overall, though, my favorite of the bunch.

The iPhone Developer's Cookbook: Building Applications with the iPhone SDK
Erica Sadun (Addison Wesley)

I'm a big fan of Erica's from her blog and applications when the iPhone and iPod Touch first appeared and were programmable. Text is easy to read. Erica often references "when the iPhone first appeared" or "during the Beta period" - often interesting insights that add some fun to the text. There are also references to many 'undocumented' APIs - they're clearly highlighted to avoid confusion, but unfortunately they're even more difficult to use from MonoTouch than Objective-C... I felt a bit "left out" on first reading, although with btouch in MonoTouch 1.2 I'm wondering whether it might be easier to access these APIs now? (even though we're not supposed to...)

Chapter 2 - Views - does a really nice job of gradually introducing various concepts, and the Objective-C is minimal. That chapter on it's own is probably worth reading for anyone coming to iPhone programming. The rest of the first half is also fairly easy to follow (View Controllers, Basic Tables) - if the examples were in C# they might be my favorite 'introduction to iphone programming' :)

Towards the end of the book the amount of Objective-C does increase to a few multi-page listings that are more difficult to read (and probably beyond beginning C#ers) but overall the book is good value.

There is a 2nd edition due in January 2010 which will probably address my other main concern with this book: that it pre-dates the latest iPhone OS releases and hardware. Not a big deal really, but it's always nice to have info on the latest and greatest.

iPhone SDK Application Development: Building Applications for the AppStore
Jonathan Zdziarski (O'Reilly)

Less "reading" in this book - rather than longer explanatory paragraphs the author uses smaller chunks of text interspersed with bullet points, callouts and small and large Objective-C listings. This actually makes it better as a reference book than a front-to-back learning tool - and that makes it more suitable for MonoTouch in my view.

As with the other titles, the initial chapters cover Objective-C concepts like messaging, implementation, protocols, categories and posing(!) which you aren't likely to need as you start out with MonoTouch (although you might return to read about them later, to get your head around more complex examples).

I've used the remainder of the book to 'look up' various things that I want to learn about or need examples of, usually as a backup/alternative to the material that I've found in other books or on the web. It doesn't have the breadth of "Beginning iPhone Dev" nor the easy readability of Erica's stuff, but I have definitely picked up some useful tidbits from this book.


Head First iPhone Development: A Learner's Guide to Creating Objective-C Applications for the iPhone
Dan Pilone; Tracey Pilone (O'Reilly)

I love the Head First series from O'Reilly, so I was determined to like this book; and it definitely lives up to it's promise as a Head First title. The writing, imagery, exercises and screenshots are all as you'd expect and it is really good at explaining Objective-C, Xcode and Interface Builder concepts... however that's partly what makes this volume less useful for C#ers: the writers go out of their way to explain/show how to do everything with Xcode and Interface Builder! As a MonoTouch developer I find myself only in MonoDevelop writing code and building my interfaces in code... so to my dismay I find myself unable to put this book at the top of my list.

It is still a fun read, and the non-techy bits (of which there are many) are extremely relevant to ALL iPhone devs. The recommendation to design your UI on paper, to follow Apple's Human Interface Guidelines, to remember to test on a Touch, and much more... if I ever decide to really learn Objective-C, I'll probably come back to this book and run through all the examples from go-to-whoa since it does try to teach the language and the SDK (and I really need help with my memory management!).


iPhone Cool Projects
Bennett et al (Apress)

The most 'attractive' of the five, due to the easy-to-read typesetting and colorful (yes COLOR) layout and imagery; this book probably doesn't really even belong in the list. It is more of a 'discussion' of iPhone application design - there is a fair amount of Objective-C throughout but it's mainly used to illustrate points of discussion, and the chunks are small enough that a C# developer can easily scan them.

Definitely fun to read - but you'll want any/all of the other books first to advance your knowledge of the iPhone SDK and Objective-C before you start trying to use the examples in this book. It probably isn't a good choice as a 'reference' or a learning tool for C#ers until you've got a few apps under your belt.


Finally...
As time passes and my knowledge increases my opinion of these books might change. Perhaps others have different opinions on what makes a good "Obj-C for C#" book, or have come across other titles? I'm sure there'll be C#/MonoTouch specific titles on the market eventually - it will be interesting to see how they read too!

Another MonoTouch 'conference app' - PDC09

I'm not planning on making a habit of this, but having spent the time putting together the Monospace conference app and seeing tweets from various Mono people that they were heading to PDC09, I figured it wouldn't take too long to copy some PDC data into the existing MonoTouch C# app 'framework'.

A new view (Sessions), a new icon (Speakers) and a new location (Underground) are the main changes - the rest is just SQLite and graphic tweaks. The source is available for download - PDC09_01.zip (124Kb).



NOTE: This is for demonstration purposes only - the Speakers data is incomplete and the Schedule & Sessions are subject to change! Use at your own risk :)

UPDATE: to be clear, this app is not available on the AppStore -- it is just an example of the kind of thing you can write in C# for the iPhone using MonoTouch from Novell. If you have a MonoTouch licence then you can download the source (124Kb) and install it on your phone.

MonoTouch UINavigationController Placemat

In one of my other posts I included a 'placemat' diagram to help make sense of the code.

Someone commented that they found the presentation useful, so as a quick post today I decided to placemat the Roget's 1911 Thesaurus sample.



Note that I'm not suggesting this is the neatest, tidiest, best-practice way to structure a MonoTouch application (I'm learning along with everyone else). This is purely to help you find your way around the example code.

For example... on thing I learned is that I didn't really need to pass an instance of the 'root' MainViewController around - each UIViewController has a NavigationController property referencing the UINavigationController that 'contains' it. Therefore any given UIViewController that has been added to a UINavigationController can call this.PushViewController (or else pass a reference to this into the UITableViewDelegate constructor to use in RowSelected.

MonoTouch "Corp411" (part III: Revenge of System.Data)

As promised, the Corp411 sample app has been 'converted' from sqlite-net to System.Data. MonoTouch 1.2 isn't quite out yet, so you must follow the instructions on this page to download the System.Data assemblies to your installation, put them in the correct place AND add references to your MonoDevelop solution for Mono.Data.Sqlite.dll, Mono.Data.Tds.dll, System.Data.dll, System.Transactions.dll (I'm not sure if they're all required, but it seemed like a sensible set).

It's pretty easy to use after all that:

// db is the path to the SQLite database file
var conn = new SqliteConnection("Data Source=" + db);

and

listData = new List<Employee>();
// System.Data from http://monotouch.net/Documentation/System.Data
var sd = new SystemDataHelper("phonebook");
var connection = sd.GetConnection();
using (var cmd = connection.CreateCommand())
{
   connection.Open ();  
   cmd.CommandText = "SELECT Firstname, Lastname, Work, Mobile,"
                   + "  Department, Email "
                   + " FROM Phonebook ORDER BY Lastname";  
   using (var reader = cmd.ExecuteReader ()) 
   {
      while (reader.Read ()) 
      {  
         var emp = new Employee();
         emp.Firstname = (string)reader["Firstname"]; 
         emp.Lastname = (string)reader["Lastname"]; 
         emp.Work = (string)reader["Work"];
         emp.Mobile = (string)reader["Mobile"]; 
         emp.Department = (string)reader["Department"]; 
         emp.Email = (string)reader["Email"];
         Console.WriteLine("Column {0}",reader["Lastname"]);
         listData.Add(emp);
      }  
   } 
}

Cool eh? Doesn't that look familiar... good old ADO.NET :-)


THE CODE
That's a small part of the System.Data namespace, so the code is pretty small :) here 'tis Corp411.3.zip (38Kb)

... and proof it runs on a device ...