MonoTouch iPhone Development

In general, and this is not a universal truth, but in most cases products with obnoxious monkey’s in their logos are pretty good.  Despite this hard to dispute observation, I have been reluctant to try MonoTouch out.  MonoTouch is a development enviornment for iPhone which allows you to develop in C#/.NET.

Recently, some respected colleagues prompted me to give it a shot.  I didn’t need much motivation aside from their assurances that it didn’t suck, because after years of trying to peacefully coexist with Objective C, I’m about ready to give up.  When OS X came out, I recall thinking “Cool…now I can teach myself to program for this…what fun.”  Then I cracked open the Objective C book and had to be put on oxygen.  This is my impression of Objective C…

Yep, NeXT took C, a perfectly serviceable computer language and grafted alien DNA into it to make it Object Oriented.  Ever see the Telepod accident in the movie “The Fly” that produced Brundlefly?  Objective C is the computer language equivalent.

My next confession is a difficult one to make.  I like C# and .NET.  I’m comfortable with C# having been a Java developer back in the 90′s when Java was cool and not funded by the Yahoo Toolbar (what’s up with that Java?) and spent a few years doing ASP.NET.  C# was a very skillful ripoff of that highly successful, but aging, language.  All in all, a decent language.  Yes, I make fun of .NET developers, having been one myself, but the thought of coding for iPhone in C# rather than Objective C (shudder) had a lot of appeal.  So off I went to download MonoTouch.

Installation

I thought a good first step would be to install it.  I don’t read instructions, so I downloaded the trial package, installed it, then could not find it.  Eventually I realized that MonoTouch requires separate downloads of the Mono SDK and MonoDevelop IDE.  Probably should have read the instructions, but eventually I got everything installed.  MonoDevelop 2.4 elected to annoy me by informing me that a new version was available…which prompted me to download MonoDevelop 2.4.  I went through that about 8 times before I caught on….

On to the Code

With everything installed, I decided not to stray too much from the introductory tutorial.  It is a bit out of date, but hopefully not too many pitfalls.  I was presented with an easy to follow create solution wizard.

Hitting the ‘OK’ button caused it to crunch and grind and produced the following code framework.

using System;
using System.Collections.Generic;
using System.Linq;
using MonoTouch.Foundation;
using MonoTouch.UIKit;

namespace HelloiPhone
{
 public class Application
 {
 static void Main (string[] args)
 {
 UIApplication.Main (args);
 }
 }

 // The name AppDelegate is referenced in the MainWindow.xib file.
 public partial class AppDelegate : UIApplicationDelegate
 {
 // This method is invoked when the application has loaded its UI and its ready to run
 public override bool FinishedLaunching (UIApplication app, NSDictionary options)
 {
 // If you have defined a view, add it here:
 // window.AddSubview (navigationController.View);

 window.MakeKeyAndVisible ();

 return true;
 }

 // This method is required in iPhoneOS 3.0
 public override void OnActivated (UIApplication application)
 {
 }
 }
}

I can actually read this…because it’s not Objective-C!

Building the UI

The wizard had created a MainWindow.xib file.  Double clicking on it launched the old, familiar Interface Builder.  The tutorial prompts you to create a button and label on the blank window and wire them to the app delegate handlers.  I won’t go into it as we’re focusing on MonoDevelop, but it’s done in the usual way for iPhone development.

Adding Behavior – First Glitch

We have our connections to the UI elements, but not much is going on now.  The tutorial makes the following statement…

“We are going to create two class outlets in the application delegate. Each outlet that we create in the user interface will be reflected as a property in a partial class in the MainWindow.designer.xib.cs file.”

Hmmm…mine didn’t.  I don’t have references to my new button and label objects anywhere in the C# code, so needless to say I can’t proceed to adding any behavior.  Remember what I said about reading the instructions?  The installation section of the MonoTouch documentation also said this in large friendly RED letters:

“* You MUST install the latest release of Mono before installing MonoTouch“

Bummer…I was really hoping to blame the tool rather than my own stupidity…:(.

Adding Behavior – Next Try

Here we go again.  After reinstalling the MonoTouch package AFTER having installed Mono, I recreated my steps from before with the new solution name RTFM.  EUREKA!  Just kidding, the %#$%!^* still didn’t work!  Still highly motivated to avoid Objective-C at all costs, I re-read the various installation commentaries for both Mono, MonoTouch and MonoDevelop and found this critical, but well hidden, pearls of wisdom again in large friendly RED letters.

“* You MUST use the MonoTouch version of MonoDevelop from the above link, or the version from MonoDevelop’s built-in updater, since it may contains fixes that are not in MonoDevelop 2.4.”

There’s no easy way of determining if you have installed MonoDevelop 2.4 or MonoDevelop 2.4 iPhone enabled.  I followed the link from the MonoTouch page and reinstalled MonoDevelop.  I created RTFMPartDeux and…gasp…something was different.  Like Groundhog Day…different is good.  The MainWindow.xib.designer.cs file was in a heirarchy under MainWindow.xib!

Sure enough, when I retraced my steps the MainWindow.xip.designer.cs file created references to my button and label objects which I could use to add some behavior in the ApplicationDelegate.

Adding Behavior – Finally!

Ok, with all my prior screw ups rectified, I added the following handler to the app per the tutorials instructions.

int ntaps = 0;

button.TouchDown += delegate {
    label.Text = "I have been tapped " + (++ntaps) + " times";
};

This time, building and running it worked fine with the finished masterpiece looking like this…

The Verdict

Too early to tell, but I’m impressed so far.  All of the problems I encountered were self inflicted so I can’t really blame MonoTouch for anything other than having instructions which are not idiot proof (I’m an exceptional idiot).  Now that I’ve got an app that counts upward when you hit a button, I will implement a gene sequencing application to reverse engineer the human genome complete with 3D molecular rendering to see if it really is a solid solution.

My only reservation at present is any hidden quirks that would not surface after man weeks of development.  I’ll be test driving this a bit more in upcoming days to stretch it’s capabilities a bit and see what I find.