Xamarin.iOS multiple asset catalogs

Question

With the newest Xamarin Studio (4.0.13) I'm trying to use asset catalogs in my app. The app has two different app icon sets: one for all test (Test.plist) and staging (Staging.plist) builds, and one for all pre-production (PreProduction.plist) and Production (Production.plist) builds. The test bundle contains NO app icons, since we want QA to be clear this is NOT the same as a production build.

I've already started doing a Pre-Build plist cp step (not ideal; Xamarin Studio should support conditionally including files based on build config). Is there a way to conditionally bundle (build action ImageAsset) the .appiconset and .launchimage specific to my build configuration? I've specified the relevant XSAppIconAssets and XSLaunchImageAssets, but since they're all marked ImageAsset they all get copied in anyway, and (unfortunately) copied into the root folder where Springboard can find and display them.

Is there any way around this without:

• Adding yet more Pre-Build cping to bundle the correct icon sets into one set which is the only one marked ImageAsset:

  cp iPhone/buildPlists/Staging-Info.plist Info.plist;
  cp -r Resources/Images.xcassets/TestAppIcons.appiconset/*
        Resources/Images.xcassets/AppIcons.appiconset;
  cp -r Resources/Images.xcassets/TestLaunchImages.launchimage/*
        Resources/Images.xcassets/LaunchImages.launchimage
  

• Adding blank image files to the TestAppIcons.appiconset catalog? This doesn't work, the order icon sets are copied to the output folder is undefined

Answer 1

I've used the above cp script which has essentially solved my problem.

More information which may help others:

You can't rely on XSAppIconAssets and XSLaunchImageAssets being checked AFTER you do a Pre-Build plist copy step. Xamarin Studio appears to use the values present in Info.plist at the beginning of the build process.

Asset catalogs work the following way under the hood:

• In general, catalog images are copied into the .app in the form CatalognameModifiers.ext (e.g. LaunchImages@2x.png)
  • For Launch Images, the catalog name is assigned to the UILaunchImages key in Info.plist, and the OS handles the lookup of these transparently
  • For App Icons, the Icons are renamed to CatalognameDimensions.ext, including the 57x57 (which previously were simply Icon.png/Icon@2x.png), and these names are assigned to arrays under the CFBundleIcons and CFBundleIcons~ipad keys in Info.plist

As a result of the above renaming, you need to specify the catalog name, not the 'asset name' as mentioned here. In my case, I was puzzled over launch images suddenly not appearing in the app (my app moves from a splash screen to a loading spinner over the splash image). The solution was changing the code to request UIImage.FromBundle("LaunchImages"), rather than "Default". Note that for iPhone 5 you currently need to request "LaunchImages-568h" to get the right image.