Xamarin's support for the iOS 9 Releases
The Xamarin.iOS 9.0.x series introduces support for Apple's iOS 9.0 APIs and Xcode 7. It is based on the stable Mono 4.0 release.
You will need to use Mac OSX 10.10.4 (Yosemite) to run this new version of Xamarin.iOS along with Xcode 7. Until El Capitan is out of preview we advise you to use Yosemite for your stable development environment.
New iOS frameworks
Apple added several new frameworks in iOS 9, including:
and Xamarin.iOS 9 includes bindings for all of them.
Generic-based NS* collections
New API that uses (as parameters or return values) collections where the types are known are now bound to generic collection like:
Support for Embedded Frameworks
It is now possible to use Embedded Frameworks in Xamarin.iOS projects. This is Apple's way of packaging shared libraries, they are useful for sharing native code between multiple components of your app (your main application and your extensions) or to easily add third party frameworks to an app .
There are several ways of including embedded frameworks in your app:
--framework /path/to/my.frameworkas an Additional mtouch argument.
- In a future release of Xamarin Studio and Visual Studio it will be possible to add frameworks to the project using the UI; in the meantime project files can be edited manually to add the required sections. Examples can be found in the embedded-frameworks github repository.
- Frameworks can also be added to binding projects, although this also requires manual editing of project files (once again there are examples in the embedded-frameworks github repository).
Embedded frameworks only work on iOS 8.0 and higher.
Xamarin.iOS takes advantage of this to automatically bundle the Mono runtime as a framework when it detects it will be beneficial (this typically happens when using extensions, since otherwise the Mono runtime would be bundled once for the containing app and once for each extension).
This behavior can be controlled with the
line option to mtouch, you can select
--mono=static to force
static linking or
--mono=framework to force the use of a
Mono.framework in your project. You’ll have to add the
same option to the containing project and all extension projects, otherwise
it’s possible to end up with an app where the extensions think there’s a
Mono.framework in the app, but the containing app doesn’t
bundle it because it’s statically linked.
More examples showing how this can be used for linking with native frameworks and invoking manually, using it for C# bindings to Objective-C APIs and how this is used with many extensions can be found in embedded-frameworks github repository.
 While frameworks are convenient units of deployment, they are not processed by the native linker, so if you are merely using a limited set of features from a framework, you won’t get the size benefits that come from statically linking (which would only include the pieces of the static library that is actually used by the app).
Simulator Launch Time Improvements
We’ve significantly improved the startup time in the simulator for certain scenarios by shipping all the Objective-C metadata in Xamarin.iOS.dll in a preprocessed form. This avoids having to process any metadata from Xamarin.iOS.dll at startup, and typically saves 1-2 seconds.
Better nullability support
Our class libraries takes advantage of Apple’s addition of nullability information in their header files. The presence (or absence) of null checks is now based on this information. Previously this was based on Apple's documentation, which was not always up to date.
Apple introduced a few breaking changes in the iOS9 SDK that you should be aware of:
- Changes in EventKit[UI] enum base types, now
NSInteger. Different sizes are now used in 32/64 bits [rdar://21375616]
EKErrorenum values were re-numbered [rdar://22133323]
This is a service release fixing the following issues:
- [msbuild] Reduce XcodeCompilerToolTask verbosity [#33706]
- [registrar] Fix blocks registration [#34052]
- [runtime] Remove duplicated symbol in libmonotouch [#34186]
- [foundation] Remove INativeObject API in NS[Mutable]Dictionary [#34213]
- [replaykit] Fix StopRecording's handler signature [#34220]
- [registrar] Handle ref/out IntPtr in the registrars correctly [#34224]
- [fastdev] Ensure libraries we ship/produce for fastdev have deployment target 7.0 (or higher) [#34267]
This is Xamarin's official release to support iOS9 SDK and, now that our audit and tests are completed, offers API stability with future release. Also our runtime was updated to our latest mono used in XI 8.10.5 (Service Release 4).
The following document contains a complete list of the API changes from 8.10.5 to 9.0.1.
- [cecil] Fix regression for async methods compiled with VS2013 [#33124] 188.8.131.52+
This is a beta release based on Apple’s GM release of the Xcode7 and iOS 9 SDK. We believe this to be complete and working but we’re still auditing the API and testing the changes in the latest bits. You can use this build to submit to the app store but it’s possible that the upcoming stable build might have some slight differences.
The following document contains a complete list of the API changes from 8.10.3 to 9.0.0.