Supporting iOS 6.1 and iOS 7 (Xamarin.iOS)

As a developer it’s always way more fun to play with the new “toys” a new framework or OS provides. The issue we usually run into is at what point are we able to start using the new functionality in applications we develop. With Apple and iOS, the adoption rate of new versions is so high and so quick that you only really need to worry about supporting the 2 latest versions. With that said, if you’re starting something brand new you’ll probably just want to build against the newest version, but if you’ve got an existing application that you want to function in both versions you’ll need to do some work.

1st: If you don’t have Xcode 5, copy the iPhoneOS6.1.sdk and the iPhoneSimulator6.1.sdk folders from your existing Xcode 4.6.3 installation somewhere else so you can still dev for iOS 6. The simulator SDK can also be downloaded after the upgrade, but this is faster since you already have it on your machine. The SDKs are located under /Applications/Xcode.app/Contents/Developer/Platforms. In Finder choose Go => Go to Folder to get to the desired directories. Copy both of these folders somewhere else for use later.

  • iPhoneOS6.1.sdk is located here /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/
  • iPhoneSimulator6.1.sdk is located here /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/

NOTE: If you’ve already upgraded to Xcode 5 you’ll need to download the Xcode 4.6.3 installer from the Apple Developer site located here. Once downloaded, open the .dmg file and right-click on the Xcode icon, choose “Show Package Contents” and then follow the same directory structure to get to the SDK folders.

2nd: In order to support iOS 7 make sure you are upgraded to OS X 10.8.5 and Xcode 5.

3rd: With Xcode 5 installed copy the iPhoneOS6.1.sdk and iPhoneSimulator6.1.sdk folders back to the directories you copied them out of. You should notice 7.0 versions of each SDK now in those directories as well.

4th: In Xamarin Studio under the iOS Build view in your project options, you’ll now notice that you have the ability to specifiy 6.1 as the SDK version as well as 7.0. Under the iOS Application view is the more important Deployment Target property. Set this to 6.1 in order for the application to still be deployable. Otherwise only iOS 7 devices will be able to get it from the app store. Making this change will allow it to be deployable for both versions, but you still have one more thing.

5th & Last: Apple made some drastic changes with how certain properties work, how the NavigationController’s title bar and the iOS status bar look and work, and a bunch of other things. You’ll need to add version specific code to handle/fix these changes. I created a VersionHelper static class to do the comparison logic for me. There are definitely other ways to accomplish this but here it is:

public static class VersionHelper
{
	private static Version _systemVersion;
	public static bool CurrentVersionIsGreaterThanOrEqualTo( Version versionToCompareAgainst )
	{
		if ( _systemVersion == null )
		{
			_systemVersion = new Version( UIDevice.CurrentDevice.SystemVersion );
		}

		return _systemVersion >= versionToCompareAgainst;
	}
}

With that you should be good to go.

One thought on “Supporting iOS 6.1 and iOS 7 (Xamarin.iOS)

  1. What Xamarin have achieved is awesome but their pricing effectively prohibits small dev firms like our from using their tools (to get iOS, Android and Mac it’s costs around $3,000 per year, per developer). I know they have different editions but we, being a VS shop, want to use VS for all of our development. I’ve gotten wind of a competitor to Xamarin who’ll be coming to the market very soon with an offering at a price which could blow Xamarin out of the water. I’m sworn to secrecy about it but expect a cost-effective way (around 1/3 of Xamarin’s pricing with cheaper renewals) to develop native apps in C# using VS for iOS, Android and Mac before the end of 2013 so keep an eye out. (I don’t work for this company but expect to shortly be a customer of theirs)

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