[matouskozak]

Extract the Apple test-app fixes from #133575 (contributes to #134856). Also fix the Xcode 27 native build.

• Use the UIScene lifecycle and start the runtime once per process.
• Raise iOS/tvOS test-app and native deployment targets to 15.0. Native binaries no longer target iOS/tvOS 13–14.
• Update stale MacCatalyst versions

Note

This PR was updated with GitHub Copilot.

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[Copilot]

🔵 Needs a closer look

Scene-gated startup across iOS, tvOS, and MacCatalyst needs device or simulator validation of launch, reconnect, and once-only execution that source inspection alone could not provide.

No open issues 🎉

What changed in this PR

Updates AppleAppBuilder’s test-app templates for the Apple 27 rollout tracked in #134856. These changes affect test-app configuration, not .NET’s platform support policy.

Changes:

• Move window and view-controller creation to the UIScene lifecycle in both templates.
• Guard runtime startup with dispatch_once to prevent repeated initialization when scenes reconnect.
• Raise the iOS/tvOS test-app deployment target from 13.0 to 15.0.

File	Description
src/​tasks/​AppleAppBuilder/​Xcode.cs	Raises the test-app deployment target to 15.0.
src/​tasks/​AppleAppBuilder/​Templates/​main-simple.m	Adds scene-based window setup and once-only runtime startup.
src/​tasks/​AppleAppBuilder/​Templates/​main-console.m	Adds scene-based window setup and once-only runtime or library-mode startup.

_{Review effort: Balanced}

[akoeplinger]

@matouskozak could you also bring the remaining minimum-OS-version references into sync with Directory.Build.props?

The iOS/tvOS minimums in this PR consistently use 15.0, but checking every path in the SetOSTargetMinVersions “keep in sync” comment found these outstanding discrepancies:

File	Current minimum	Expected minimum
src/coreclr/tools/Common/Compiler/ObjectWriter/MachObjectWriter.cs	macOS 12.0; Mac Catalyst 15.2	macOS 14.0; Mac Catalyst 17.0
src/mono/mono/offsets/offsets-tool.py	Mac Catalyst 15.2 (both target triples)	17.0
src/tasks/AppleAppBuilder/Xcode.cs	Mac Catalyst 15.2 (both IPHONEOS_DEPLOYMENT_TARGET arguments)	17.0
src/tasks/MobileBuildTasks/Apple/AppleProject.cs	Mac Catalyst 15.2	17.0

These are pre-existing omissions, not regressions introduced by this PR. The Catalyst mismatch dates to #123200, merged January 25, 2026: it raised MacCatalystVersionMin from 15.2 to 17.0 and updated the native/Mono AOT configuration, but left these four files behind.

There is also a cross-repository follow-up: dotnet/sdk main still uses macOS 12.0 in src/Layout/redist/targets/GeneratePKG.targets, rather than 14.0. The SDK path listed in the Directory.Build.props comment is stale (src/Installer/redist-installer/targets/GeneratePKG.targets) and should be updated to the new location. The SDK value itself would need a separate SDK change.

All other files referenced by that comment match the applicable minimums.

[rolfbjarne]

A couple of follow-up items for the UIScene migration:

1. Two custom NativeMainSource files still use the legacy UIApplicationDelegate lifecycle (didFinishLaunchingWithOptions: + [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]) and will crash at launch on iOS / Mac Catalyst 27 when built with Xcode 27:

   • src/tests/FunctionalTests/iOS/Device/ExportManagedSymbols/main.m
   • src/mono/sample/mbr/apple/main.m

2. [[UIScreen mainScreen] bounds] in viewDidLoad (src/tasks/AppleAppBuilder/Templates/main-console.m and src/tasks/AppleAppBuilder/Templates/main-simple.m): UIScreen.mainScreen is deprecated and does not necessarily match the scene window size (for example on Mac Catalyst or iPad multitasking). Using self.view.bounds (with appropriate autoresizingMask) would avoid relying on UIScreen.mainScreen.

🤖 Comment posted by Copilot

[matouskozak]

@rolfbjarne can I get another look please?

cc: @vitek-karas

[agocke]

I'd like to move to #136885 first, if possible.

[matouskozak]

I'd like to move to #136885 first, if possible.

Not sure if it's needed because XCode 27 is available only on arm64 images, and we're migrating to the x64 macos-26 but I can wait if you prefer.

Just a note, runtime currently doesn't build if you have XCode 27, which makes the dev loop a bit hard.

[rolfbjarne]

The updated changes in [#136566](#136566) look good to merge:

• src/mono/sample/mbr/apple/main.m and src/tests/FunctionalTests/iOS/Device/ExportManagedSymbols/main.m: Both custom NativeMainSource files now use UIScene (configurationForConnectingSceneSession:, willConnectToSession:, initWithWindowScene:, and dispatch_once around runtime init).
• main-console.m, main-simple.m, and src/mono/sample/mbr/apple/main.m: Replaced [[UIScreen mainScreen] bounds] in viewDidLoad with self.view.bounds and added autoresizingMask (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight for full-view controls, UIViewAutoresizingFlexibleWidth for summaryLabel).

No remaining issues found.

Note

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[matouskozak]

/azp run runtime-extra-platforms

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[agocke]

/ba-g azure Linux 4 failures unrelated