version:2.8.0 releasedate:2016-03-31

• The latest features and API requires Xcode 7.2 and the bundled macosx10.11 SDK;
• Apple Xcode 7.2 requires a Mac running OSX 10.10 (Yosemite) or 10.11 (El Capitan)

This release includes new support for Xamarin.Mac binding projects. They act very similar to the existing iOS binding projects, and most of the iOS documentation is applicable.

This release includes a new native NSUrlSession-based HTTP handler based on the popular ModernHttpClient open source library.

This was designed to be both a transparent (no source) change and to reduce the amount/size of application code required for the HTTP stack. As such some, non-default, options specific to ModernHttpClient are not provided. The use of ModernHttpClient is still possible from your applications as we avoided potential names/types conflicts.

An application that removes all usage of System.Net.WebRequest and use HttpClient with the new NSUrlSessionHandler can reduce it's size by about 850KB (per architecture) and benefit from the performance gains of the native stack.

To make it easier to adopt a specific handler across all HttpClient uses in your application Xamarin.iOS now allow you to set which handler should be used for HttpClient. The following options are available:

• HttpClientHandler: This is the fully managed HttpClient handler that has been shipped with previous Xamarin.iOS. It is the most compatible (features) with MS .NET and older Xamarin versions. However it's slower (e.g. encryption) and requires more code in the final application. To ensure maximum compatibility for existing applications this is the default handler.
• CFNetworkHandler: This handler uses native API (CFNetwork framework) for better performance and smaller executable size. However it requires iOS6 (or later) and it not available on watchOS. Not every HttpClient features/options are available;
• NSUrlSessionHandler: This handler uses native API (NSUrlSession) for better performance and smaller executable size. However it requires iOS7 (or later) and does not support every HttpClient features/options;

Selecting which default HttpClient handler can be done using the project's options in your IDE (XS or VS) or by providing mtouch with either --http-message-handler=HttpClientHandler, --http-message-handler=CFNetworkHandler or --http-message-handler=NSUrlSessionHandler command-line arguments.

You can now select which Transport Layer Security (TLS) provider you want to use inside your iOS application, e.g. to support SslStream, which provides the SSL/TLS support for System.Net.WebRequest and it's friends.

By default your projects will now use the new Apple TLS stack which uses native code (better performance) and support the newest TLS 1.1 and 1.2 standards. This is a change from previous preview releases of XM 2.8.

You can also opt-out and continue to use the managed Mono TLS stack, which only supports up to TLS 1.0. This will continue to use the same stack that was shipped in previous versions of Xamarin.iOS.

Selecting which TLS provider to use can be can be done using the project's options in your IDE (XS or VS) or by providing mtouch with either --tls-provider=legacy or --tls-provider=appletls command-line arguments.

This version adds generic versions of the following types:

• NSArray
• NSOrderedSet
• NSMutableOrderedSet

• Xamarin.Mac 2.8 is currently incompatible with Xcode8 when the static registrar is enabled due to the removal of header files by Apple.
  • This will be fixed in a future release.
  • Targeting Xcode 7.3 or downloading a XM from https://jenkins.mono-project.com/view/Xamarin.MaciOS/job/xamarin-macios-builds-xcode8/ are possible work arounds.
• Uses of NSLog (via p/invoke) will crash applications on macOS 10.12 Beta6 with _os_trace_location_for_address in the stack trace.

• 2.8.2.19 - 2.8.2.22

Cycle 7 Service Release 1 Update

Fixed known issue in 2.8.2.15 with System.Security.dll and link errors.

• 2.8.2.15

Cycle 7 Service Release 1

Known Issue - Some Xamarin.Mac Unified Mobile applications may fail linking with errors related to System.Security.dll. This can be worked around by disabling linking or downgrading to SR0. This will be fix in a future update.

Fixed issue where in some cases mmp under the Mobile profile would incorrectly resolve assemblies from the GAC.

• 2.8.1.3

Cycle 7 Service Release 0

Fixed "System.Configuration.DictionarySectionHandler is missing" error. #39669

Fixed "Mono.Security.Interface.TlsException: Unknown Secure Transport error `ClosedGraceful'" in certain environments when using the Managed setting for HttpClient implementation in combination with the new default Apple TLS setting for SSL/TLS implementation. #41206

Fixed [AppleTls] Certain calls to HttpClient.SendAsync() can hit a delay of about 60 seconds before completing if using the new default Apple TLS setting for SSL/TLS implementation (same fix as #41206). #41697

Fixed [registrar] "initWithCoder:' has been explicitly marked unavailable". #41319

Fixed [mono] "System.Net.WebException: Error: NameResolutionFailure" when attempting web requests with certain raw IP addresses. #41782

Fixed [mono] Reflection throws AmbiguousMatchException when calling GetProperty() on a class that inherits from a generic base class. #41874

Known issue: CGRect.Inflate() returns an unmodified CGRect regardless of the input parameters. Possible temporary workaround: Modify the frame of the CGRect by hand using the X, Y, Width, and Height properties. #41684

• 2.8.0.323

Cycle 7 initial release.

Fixed major bug in mmp that allowed resolution of assemblies from GAC in supported profiles, including System.Drawing. - #40436

Known issue: "Mono.Security.Interface.TlsException: Unknown Secure Transport error `ClosedGraceful'" in certain environments when using the Managed setting for HttpClient implementation in combination with the new default Apple TLS setting for SSL/TLS implementation. Workaround: Under Project Options > iOS Build, either change the SSL/TLS implementation setting back to the old default Mono (TLS v1.0), or set the HttpClient implementation to one of the new CFNetwork or NSUrlSession options. #41206

Known issue: Certain calls to HttpClient.SendAsync() can hit a delay of about 60 seconds before completing if using the new default Apple TLS setting for SSL/TLS implementation. Based on the information gathered so far, it seems the issue might only affect HTTPS requests that use authorization headers. Workaround: Under Project Options > iOS Build, change the SSL/TLS implementation setting back to the old default Mono (TLS v1.0). #41697

Known issue: "System.Net.WebException: Error: NameResolutionFailure" when attempting web requests with certain raw IP addresses. This is a bug in Mono, so it affects all platforms iOS, Android, and Mac. Partial temporary workaround: If possible, use domain names rather than raw IP addresses for the web requests. #41782

• 2.8.0.294

Release Canidate released at Evolve 2016

Will be published at a later date.