version:9.8.1 releasedate:2016-06-21

In this release the non-NRC (new-ref-count) option was removed. NRC has always been enabled for all unified applications (i.e. non-NRC was never an option) and has no known issues.

The next release will remove the option of using Boehm as the garbage collector. This was also an option never available to unified applications.
The complete removal of classic support is scheduled for next fall with the release of Xamarin.iOS 10.0.

• The latest features and API requires Xcode 7.3 and the bundled iOS 9.3 SDK;
• Apple Xcode 7.3 requires a Mac running OSX 10.11 (El Capitan)

The latest (4th) generation of AppleTV allows developers to create and submit applications to the Apple App Store.

tvOS is generally a subset of the iOS 9.x API where frameworks/API non-applicable to the AppleTV platform and deprecated API were removed. This includes:

• Accounts.framework
• AddressBook.framework
• AddressBookUI.framework
• AssetsLibrary.framework
• Contacts.framework
• ContactsUI.framework
• CoreAudioKit.framework
• CoreMIDI.framework
• CoreMotion.framework
• CoreTelephony.framework
• EventKit.framework
• ExternalAccessory.framework
• HealthKit.framework
• HomeKit.framework
• LocalAuthentication.framework
• MapKit.framework
• MessageUI.framework
• MobileCoreServices.framework
• MultipeerConnectivity.framework
• NetworkExtension.framework
• NewsstandKit.framework
• Photos.framework
• PhotosUI.framework
• PushKit.framework
• QuickLook.framework
• ReplayKit.framework
• SafariServices.framework
• Social.framework
• VideoToolbox.framework
• WatchConnectivity.framework
• WatchKit.framework
• WebKit.framework
• iAd.framework
• Audio/video input/capture API (e.g. AVFoundation.framework)
• Device orientation API (e.g. UIKit.framework)

with the addition of a few frameworks and types

• TVServices.framework;
• TVMLKit.framework;
• GCMicroGamepad* types;

Xamarin.iOS 9.8 supports the latest tvOS 9.2 SDK that ships with Apple's Xcode 7.3.

Along with the required API changes for tvOS several [Obsolete] API were removed from the new assembly.

The following document contains a list of the API differences between iOS and tvOS.

The HttpClient class can now use a native HTTP engine, instead of using Mono's HttpWebRequest. The section covers the details on what you need to be aware of.

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

When you use NSUrlSessionHandler, the HttpClient stack will use the iOS native NSURLSession class to perform all of its HTTP operations, instead of using the .NET HttpWebRequest. This has several advantages, among them, secure connections are a lot faster, as they use the native implementation of the crypto stack, and support for TLS 1.2 is enabled by default. Developers need to know that by using this new stack, the iOS 9 enforcement for secure server connection will be in effect.

This was designed to be both a transparent (no source) change and to reduce the amount of 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 its 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 XI 9.8.

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<TKey>
• NSOrderedSet<TKey>
• NSMutableOrderedSet<TKey>

The AOT compiler now produces {arch}.aotdata files alongside the assemblies. This reduce the size of the native executable and helps when natively linking large object files, particularly for 32 bits architectures.

Applications using resource assemblies should see a decrease in their size as the .resources.dll files are now deduplicated inside fat (32/64 bits) applications.

• Initial support for netstandard

The following document contains a complete list of the API changes from 9.8.0 to 9.8.2.

• 41597 - [tvos] The SDK version for LC_VERSION_MIN_TVOS in Mono.framework/Mono has an invalid value of 73, causing Xamarin tvOS apps to be rejected from the app store.
• 41653 - [AppleTls] Call SSLSetPeerDomainName() to support virtual domains
• 41655 - [mtouch] "Could not kill the application ... You may have to kill the application manually ... Details: Failed to start Instruments daemon on device" when attempting to deploy to certain iOS devices in certain environments. The fix for this issue provides a fallback mechanism that automatically tries the old (Xamarin.iOS 9.6) approach for launching apps if the new Instruments-based approach fails.
• 41656 - [httpclient] Unlike other handlers NSUrlSessionHandler.AllowAutoRedirect is false by default
• [httpclient] Unlike other handlers, CFNetworkHandler.CookieContainer is null by default.
• 41684 - [coregraphics] CGRect.Inflate() returns an unmodified CGRect regardless of the input parameters.
• 41963 - [msbuild] The fix for non-public Bug 35667 changes the output path of .ipa packages to omit version numbers and instead place the packages in timestamped subdirectories. That change breaks many CI scripts that depend on the old location of the .ipa files. This release adds a new IpaPackageDir MSBuild property to make it easier to customize the .ipa file output location when adjusting CI scripts to account for that change. For additional details, see the "New MSBuild property IpaPackageDir" section below.

A new MSBuild property IpaPackageDir has been added to make it easy to customize the .ipa file output location. If IpaPackageDir is set to a custom location, the .ipa file will be placed in that location instead of the default timestamped subdirectory. This feature can be used to simplify the changes needed to handle the Xamarin.iOS 9.8 breaking change in the default .ipa output location (41963). There are several possible ways to use the new property.

• For example, to output the .ipa file to the old default directory (as in Xamarin.iOS 9.6 and lower), you can set the IpaPackageDir property to $(OutputPath) using one of the following approaches. Both approaches are compatible with all Unified API Xamarin.iOS builds, including IDE builds as well as command line builds that use xbuild, msbuild, or mdtool.

  • The first option is to set the IpaPackageDir property within a <PropertyGroup> element in an MSBuild file. For example, you could add the following <PropertyGroup> to the bottom of the iOS app project .csproj file (just before the closing </Project> tag):

      <PropertyGroup>
        <IpaPackageDir>$(OutputPath)</IpaPackageDir>
      </PropertyGroup>

  • An even better approach is to add a <IpaPackageDir> element to the bottom of the existing <PropertyGroup> that corresponds to the configuration used to build the .ipa file. This is "better" because it will prepare the project for future compatibility with a planned setting on the iOS IPA Options project properties page.

    If you currently use the "Release|iPhone" configuration to build the .ipa file, the complete updated property group might look similar to the following:

      <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|iPhone' ">
        <Optimize>true</Optimize>
        <OutputPath>bin\iPhone\Release</OutputPath>
        <ErrorReport>prompt</ErrorReport>
        <WarningLevel>4</WarningLevel>
        <ConsolePause>false</ConsolePause>
        <CodesignKey>iPhone Developer</CodesignKey>
        <MtouchUseSGen>true</MtouchUseSGen>
        <MtouchUseRefCounting>true</MtouchUseRefCounting>
        <MtouchFloat32>true</MtouchFloat32>
        <CodesignEntitlements>Entitlements.plist</CodesignEntitlements>
        <MtouchLink>SdkOnly</MtouchLink>
        <MtouchArch>ARMv7, ARM64</MtouchArch>
        <MtouchHttpClientHandler>HttpClientHandler</MtouchHttpClientHandler>
        <MtouchTlsProvider>Default</MtouchTlsProvider>
        <PlatformTarget>x86</PlatformTarget>
        <BuildIpa>true</BuildIpa>
        <IpaPackageDir>$(OutputPath)</IpaPackageDir>
      </PropertyGroup>

• An alternate technique for msbuild or xbuild command line builds is to add a /p: command line argument to set the IpaPackageDir property. In this case note that msbuild does not expand $() expressions passed in on the command line, so it is not possible to use the $(OutputPath) syntax. You must instead provide a full path name. Mono's xbuild command does expand $() expressions, but it is still preferable to use a full path name because xbuild will eventually be deprecated in favor of the cross-platform version of msbuild.

  A complete example that uses this approach might look similar to the following on Windows:

    msbuild /p:Configuration="Release" /p:Platform="iPhone" /p:ServerAddress="192.168.1.3" /p:ServerUser="macuser" /p:IpaPackageDir="%USERPROFILE%\Builds" /t:Build SingleViewIphone1.sln

  Or the following on Mac:

    xbuild /p:Configuration="Release" /p:Platform="iPhone" /p:IpaPackageDir="$HOME/Builds" /t:Build SingleViewIphone1.sln

• 41963 - The fix for non-public Bug 35667 changes the output path of .ipa packages to omit version numbers and instead place the packages in timestamped subdirectories. (This more closely resembles Xcode's default output paths for .ipa packages.) CI scripts that depend on the old location of the .ipa files will need to be updated to accommodate this change. The final path of the .ipa package can be obtained from the IpaPackagePath MSBuild property any time after the _CoreCreateIpa target has run. For example, if you add the following lines to the bottom of an iOS app project .csproj file (just before the closing </Project> tag), the path of the .ipa package will be printed at the end of the build output:

    <PropertyGroup>
      <BuildDependsOn>
        $(BuildDependsOn);
        DisplayIpaPackagePath
      </BuildDependsOn>
    </PropertyGroup>
    <Target Name="DisplayIpaPackagePath">
      <Message Text="IpaPackagePath: $(IpaPackagePath)" />
    </Target>

• 41684 - 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.

• 41206 - [AppleTls] Correctly handle large read/write sizes
• 41697 - [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)
• 41319 - [registrar] "initWithCoder:' has been explicitly marked unavailable"
• 41782 - [mono] "System.Net.WebException: Error: NameResolutionFailure" when attempting web requests with certain raw IP addresses.
• 41874 - [mono] Reflection throws AmbiguousMatchException when calling GetProperty() on a class that inherits from a generic base class.

The following document contains a complete list of the API changes from 9.6.0 to 9.8.0.

• 41206 - "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.

• 41697 - 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).

• 41782 - "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.

• 41963 - The fix for non-public Bug 35667 changes the output path of .ipa packages to omit version numbers and instead place the packages in timestamped subdirectories. (This more closely resembles Xcode's default output paths for .ipa packages.) CI scripts that depend on the old location of the .ipa files will need to be updated to accommodate this change. The final path of the .ipa package can be obtained from the IpaPackagePath MSBuild property any time after the _CoreCreateIpa target has run. For example, if you add the following lines to the bottom of an iOS app project .csproj file (just before the closing </Project> tag), the path of the .ipa package will be printed at the end of the build output:

    <PropertyGroup>
      <BuildDependsOn>
        $(BuildDependsOn);
        DisplayIpaPackagePath
      </BuildDependsOn>
    </PropertyGroup>
    <Target Name="DisplayIpaPackagePath">
      <Message Text="IpaPackagePath: $(IpaPackagePath)" />
    </Target>

• 41684 - 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.

• 2508 - [foundation] Deprecate (iOS) / remove (tvOS) NSObject.[Get|Set]NativeField

• 3229 - [foundation] Fix NSUbiquitousKeyValueStore's indexer to accept a 'string'

• 12337 - [mtouch] Workaround 0 length files on FAT file system

• 19428 - [coregraphics] Add missing CGPath methods

• 24212 - [corefoundation] Provide CFBundle bindings

• 24677 - [registrar] Report an error if a type is used that isn't present in the current SDK

• 28610 - [audiotoolbox] AudioQueue.AudioStreamPacketDescription property has ambiguous name

• 29977 - [security] Add SecItem.ReturnData when querying several SecRecord

• 31427 - [foundation] Make NSSession.CreateDownloadTaskAsync keep track of the file so that it's not deleted too early

• 31484 - [audiotoolbox] AudioConverter properties unnecessary read-only

• 32084 - [registrar] Sanitize exported names a bit better

• 32511 - [registrar] Fix use properties on JSValue objects

• 33695 - [mtouch] Provide better error message for kApplicationVerificationFailedError

• 33709 - [objcruntime] Add a ctor to Protocol so that protocols can be marshalled

• 33789 - [runtime] Disable the GC pump when a profiler is attached

• 33800 - [mtouch] Add MT1110 for when the app couldn't be launched due to lack of trust

• 34106 - [simulator] Resolve symlinks when checking if a running simulator matches the simulator we want to launch

• 34313 - [mtouch] Improve MT1019 / 0xe8008016 error to suggest the device might not be part of the current provisioning profile

• 34363 - [msbuild] Explicitly resolve more paths to their real paths

• 34372 - [healthkit] Add missing constant (#define) for HKAnchoredObjectQueryNoAnchor

• 34378 - [mtouch] Detect and report properly when trying to export structures containing classes

• 34449 - [foundation] Expose NSSetService.GetStreams

• 34464 - [foundation] NSOrderedSet has wrong implementations for == and != operators

• 34519 - [runtime] Don't create a XamarinAssociatedObject to hold a gchandle if there's no gchandle to hold

• 34687 - [msbuild] strip depends on xcode-select path

• 34806 - [registrar] Show a nice error if the user tries to export a property that matches an Objective-C keyword

• 34913 - [uikit] Add missing UITextInput SelectionAffinity property

• 35011 - [foundation] Add missing members for NSFileVersion

• 35013 - [foundation] Add missing members for NSCalendar

• 35030 - [mtouch] Xcode path with space causes build failure

• 35048 - [coretext] Fix char marshaling in CTFontGetGlyphsForCharacters

• 35214 - [msbuild] Don't try to parse device-specific build properties for WatchOS apps

• 35283 - [generator] Allow processing enums that lives outside a namespaces

• 35304 - [mtouch] Improve MT0034 to detect more variations of incorrect references

• 35372 - [linker] Don't remove external module references from non-linked assemblies

• 35458 - [registrar] Call the super's constructor if we already have a managed object

• 35562 - [mtouch/mmp] Use full paths in DllImports

• 35599 - [uikit] Add UIControl event for PrimaryActionTriggered

• 35648 - [coreanimation] Treat CALayer subclasses as toggle ref objects

• 35825 - [coretext] Add missing CTFontManagerCreateFontDescriptorsFromURL binding

• 35829 - [cfnetwork] Read data every time we get a HasBytesAvailable event

• 35846 - [uikit] Fix wrong signature for UIPopoverPresentationControllerDelegate.WillRepositionPopover

• 35855 - [aot] Fix support for runtime invokes to array accessors of reference arrays

• 35864 - [mtouch] Only allow -bitcode if -llvm is also provided

• 35924 - [foundation] Allow null in NSObject Protocol members

• 35946 - [mtouch] The --enable-repl option should give an error if linking is enabled

• 36148 - [registrar] Only upper-case a-z when uppercasing the first character of getters for setters.

• 36208 - [simulator] Watch 1 apps don't have to be named 'WatchApp.app'

• 36247 - [aot] Escape some characters in method names to avoid assembler problems with obfuscated assemblies

• 36263 - [llvm] Zero extend array indexes when targeting llvm, codegen problem on arm64

• 36293 - [mtouch] Add -framework and -l[ibrary] based on assemblies too

• 36370 - [aot] Add instances of EnumEqualityCompater for all integer types

• 36457 - [generator] Add support for returning System.String from delegates/blocks

• 36505 - [mtouch] Add support for pseudo frameworks that contain static libraries

• 36571 - [security] Fix SecAccessControl to behave like an INativeObject

• 36575 - [metalperformanceshaders] Expose missing MPSRectNoClip

• 36577 - [linker] Re-saving forwarders (e.g. PCL facades) must exclude removed types

• 36723 - [aot] Fix the check in mono_aot_get_plt_entry () for thumb code

• 36768 - [coreimage] Add missing FromContext(EAGLContext) overload that accept a CIContextOptions

• 36992 - [security] Fix RawSign not to predict the required size (as it won't work for EC)

• 37004 - [msbuild] CreateAssetPackManifest: Fix creation of OnDemandResources.plist

• 37079 - [jit] Fix the support for gshared types in mini_emit_initobj ()

• 37105 - [runtime] Wrap threadpool work in an NSAutoreleasePool

• 37118 - [linker] Avoid an NRE when rewriting bindings

• 37121 - [social] Add missing async version of SLRequest.PerformRequest

• 37174 - [uikit] Make UITextAttributes thread safe

• 37187 - [generator] Be a bit more defensive when converting pointers to CMSampleBuffers

• 37236 - [llvm][arm64] Fix hfa structures / skipped fp registers

• 37246 - [bcl][system] Make SmtpClient fallback to it's old behaviour if the hostname cannot be resolved

• 37273 - [llvm] Disable support for nested clauses

• 37310 - [healthkit] Fix incorrect signature for HKStatisticsCollectionQuery.StatisticsUpdateHandler

• 37412 - [llvm] Fix the linking of the bblocks containing endfinally instructions

• 37536 - [coregraphics] Copy the input buffer in CGDataProvider when we don't own it

• 37596 - [uikit] Use the correct protocol type for UIImagePickerController's ImagePickerControllerDelegate and NavigationControllerDelegate properties

• 37611 - [mtouch] Gather assemblies referenced only by custom attributes

• 37670 - [objcruntime] Don't return a non-user type from Runtime.TryGetNSObject if it's being collected

• 37732 - [bcl][system] Avoid reflection use to create NtlmSession

• 37774 - [simulator][odr] Launch asset provider after installing the app

• 37993 - [foundation] Fix support for NSFileManager.ProtectionKey

• 38259 - [coreimage] Fix CIFilter check for inputImage support

• 38379 - [llvm] Zero extend unsigned enum arguments

• 38484 - [coremedia] Fix constructor for CMVideoFormatDescription

• 38612 - [registrar] 'export' is a keyword in Objective-C, so report it as such

• 38742 - [opentk] Add ES30 overload to CVOpenGLESTextureCache.TextureFromImage

• 7728 - [mtouch] Validate that an app is signed with a valid provisioning profile for a device [9.8.0.43+]

• 35888 - [registrar] Detect 'template' as an ObjC++ keyword [9.8.0.43+]

• 37527 - [generator] Provide more information when Delegates are not correctly defined [9.8.0.43+]

• 37563 - [linker] Queryable.AsQueryable uses reflection and needs help [9.8.0.43+]

• 38244 - [msbuild] Always add unpacked resources from library projects [9.8.0.43+]

• 38267 - [msbuild] Fix actool task [9.8.0.43+]

• 38434 - [msbuild] ACToolTask - Changes output AssetPack plist path to relative [9.8.0.43+]

• 38542 - [mtouch] Take into account assemblies added by the linker when loading cached linker results [9.8.0.43+]

• 38673 - [msbuild] Validate each extension's CFBundleShortVersionString and CFBundleVersion [9.8.0.43+]

• 38834 - [mtouch] libapp/extension/watch-extension.a need to be force-loaded [9.8.0.43+]

• 38886 - [avfoundation] AVCaptureMetadataOutput.SetDelegate should accept null parameters [9.8.0.43+]

• 39137 - [aot] Set null uw_info for tramps without unwind info [9.8.0.43+]

• 39179 - [mtouch][tvos] Map P/Invokes from openal32 to OpenAL [9.8.0.43+]

• 35667 - [msbuild] Output the *.ipa w/o a version and inside of a timestamped directory [9.8.0.58+]

• 39427 - [msbuild] Add back logic for the obsoleted ObjCBindingNativeFramework build action [9.8.0.58+]

• 39706 - [spritekit] Provide better bindings for SKShapeNode.FromPoints [9.8.0.156+]

• 39822 - [audiounit] Have AUGraph implements INativeObject to ease 3rd party bindings [9.8.0.156+]

• 39869 - [msbuild] Don't duplicate actool specification entries for on-demand resources [9.8.0.156+]

• 13538 - [bcl] Avoid printing debug messages to stdout in the default trace listener when a debugger is connected [9.8.0.236+]

• 34880 - [uikit] UIImage.Size will put the UIImage on an autorelease pool, so make sure we free that early [9.8.0.236+]

• 40019 - [photos] Add missing enum SmartAlbumSelfPortraits and SmartAlbumSelfPortraits values [9.8.0.236+]

• 39974 - [coremedia] Do not free provided (like managed) memory given to CMBlockBuffer [9.8.0.244+]

• 40108 - [runtime] ConditionalWeakTable collects values when the key is kept alive as toggle-ref [9.8.0.244+]

• 18334 - [foundation] Add "missing" NSAttributedString::attributedStringWithAttachment [9.8.0.294+]

• 37979 - [msbuild] ACTool task needs to know if it is a WatchOS1 app to use correct --platform value [9.8.0.294+]

• 39172 - [jit] Avoid returning trampolines from mini_jit_info_table_find since they might have no unwind info [9.8.0.294+]

• 40137 - [msbuild] Set an ArchiveDir property when the archive target is run [9.8.0.294+]

• 40318 - [msbuild] Application with entitlements do not start on simulator anymore [9.8.0.294+]

• 40458 - [linker] Do not remove parameter names (metadata) if it's used thru reflection [9.8.0.294+]

• 40534 - [msbuild] iOS build targets cannot be used with non-default keychain [9.8.0.294+]

• 40535 - [Xamarin.Hosting] Make errors 1901 and 1902 warnings [9.8.0.318+]

• 40641 - [linker] Fix debugging of watchOS apps when link all is used [9.8.0.318+]

• 40774 - [repl] Ensure Aes.Create works, otherwise SSL/TLS will break [9.8.0.318+]

• 40961 - [msbuild] Don't treat unsupported iCloud entitlements as errors in the build [9.8.0.318+]

• 41019 - [msbuild] Fixed Optimize parsing logic for BundleResources [9.8.0.318+]

• 40306 - [threadpool-io] Fix crash on shutdownin System.Net.Sockets.Socket:Close_internal [9.8.0.319+]