Support .NET 9.0

[bijington]

Description of Change

Linked Issues

• Fixes [BUG] Wrong item is registered when pressing an item in a CollectionView using TouchBehavior #1865
• Fixes [BUG][Regression][8.0.1] TouchBevavior binding not working in a CollectionView #1804
• Fixes [BUG] Camera View - Zoom does not work when application is built in release mode  #2109
• Fixes [BUG] Toast Faults on Windows #2356
• Fixes ImageResourceConverter fails to display image - .NET 9 #2354
• Fixes [BUG] Warning when including a ValueConverter starting in .NET MAUI 9 #2205
• Fixes [BUG] Net 9 Android - StatusBar Color overriden on modal pages #2370
• Fixes [BUG] .Net 9 Android MediaElement stops playing video #2373
• Fixes [BUG] TouchBehavior crash  #1783
• Fixes [BUG] Camera view with .NET 9 is causing crash on Android #2377
• Fixes [BUG] System.MissingMethodException No constructor found for CommunityToolkit.Maui.Behaviors.TouchBehavior+AccessibilityListener #2383
• Fixes [BUG] Buttons not firing inside Layout that has a TouchBehavior #2385
• Fixes [BUG] Media Element cannot be disconnected #2388
• Fixes [BUG] IconTintColorBehavior Not Reapplied When Reusing Views #2275

PR Checklist

• Has a linked Issue, and the Issue has been approved(bug) or Championed (feature/proposal)
• Has tests (if omitted, state reason in description)
• Has samples (if omitted, state reason in description)
• Rebased on top of main at time of PR
• Changes adhere to coding standard
• Documentation created or updated: https://github.com/MicrosoftDocs/CommunityToolkit/pulls

Breaking Changes

Major Breaking Changes

• .NET 8 no longer supported
• Xcode 16.1 Required
• Stop automatically assigning Behavior.BindingContext
  • .NET MAUI Behaviors do not automatically inherit their parent's BindingContext (a breaking change from Xamarin.Forms)
  • Going forward, the .NET MAUI Community Toolkit will follow this implementation of Behaviors
• Increase minimum supported OS versions of CommunityToolkit.Maui.MediaElement
  • Android 26.0
  • iOS 15.0
  • MacCatalyst 15.0
• Increase minimum supported versions of CommunityToolkit.Maui.Camera to 15.0:
  • iOS 15.0
  • MacCatalyst 15.0

Minor Breaking Changes

• Expander is not trim safe
• ValidationBehaviors are not trim safe
• CommunityToolkit.Maui.Maps is not trim safe
• Remove PopupService.ShowPopop(TViewModel)
  • Removes [Obsolete] method
  • Use PopupService.ShowPopup<T>() instead
• Remove PopupService.ShowPopopAsync(TViewModel, CancellationToken)
  • Removes [Obsolete] method
  • Use PopupService.ShowPopupAsync<T>() instead
• Remove ability to subclass BaseConverter<TFrom, TTo>
  • Subclassing from BaseConverter<TFrom, TTo> is not supported
  • Support requires documentation and complete unit tests
• Remove ability to subclass BaseConverter<TFrom, TTo, TParam>
  • Subclassing from BaseConverter<TFrom, TTo, TParam> is not supported
  • Support requires documentation and complete unit tests
• ValidationFlags.ValidateOnFocusing renamed to ValidationFlags.ValidateOnFocused
• ValidationFlags.ValidateOnUnfocusing renamed to ValidationFlags.ValidateOnUnfocused
• In CommunityToolkit.Maui.Camera, add linker.xml for net9.0-android to avoid the Linker removing Xamarin.AndroidX.Camera.Core, Xamarin.AndroidX.Camera.Lifecycle, Xamarin.AndroidX.Camera.Video, Xamarin.AndroidX.Camera.View, and Xamarin.AndroidX.Camera.Camera2
• public static Task<bool> ShowKeyboardAsync(this ITextInput, CancellationToken) -> public static ValueTask<bool> ShowKeyboardAsync(this ITextInput, CancellationToken)
• NuGet package will not support Microsoft.Maui.Controls .NET 10 until .NET 10 GA

Analyzer Benchmarks

.NET 9.0	Mean	Error	StdDev	Median	Gen0	Gen1	Allocated
VerifyNoErrorsWhenUseMauiCommunityToolkit	8.863 ms	0.1748 ms	0.3240 ms	8.724 ms	62.5000	31.2500	1.59 MB
VerifyNoErrorsWhenUseMauiCommunityToolkitHasAdditionalWhitespace	8.695 ms	0.1654 ms	0.4358 ms	8.528 ms	62.5000	31.2500	1.59 MB
VerifyErrorsWhenMissingUseMauiCommunityToolkit	12.071 ms	0.3756 ms	1.0470 ms	11.546 ms	66.6667	-	2.29 MB

.NET 8.0	Mean	Error	StdDev	Median	Gen0	Allocated
VerifyNoErrorsWhenUseMauiCommunityToolkitMediaElement	9.763 ms	0.1928 ms	0.4765 ms	9.633 ms	31.2500	1.46 MB
VerifyNoErrorsWhenUseMauiCommunityToolkitMediaElementHasAdditonalWhitespace	9.565 ms	0.1862 ms	0.4637 ms	9.460 ms	31.2500	1.46 MB
VerifyErrorsWhenMissingUseMauiCommunityToolkitMediaElement	15.495 ms	0.3879 ms	1.0814 ms	15.058 ms	66.6667	2.24 MB

[hansmbakker]

The errors are because in https://github.com/CommunityToolkit/Maui/blob/feature/sl-dotnet-nine/azure-pipelines.yml the .NET SDK to install is

• set to the LATEST_NET_VERSION variable instead of picking up the version from global.json
• set to prevent using prereleases (both in global.json and in azure-pipelines.yml)

See

Maui/azure-pipelines.yml

Lines 73 to 78 in c4169ed

	- task: UseDotNet@2
	displayName: 'Install Latest .NET SDK, v$(LATEST_NET_VERSION)'
	inputs:
	packageType: 'sdk'
	version: '$(LATEST_NET_VERSION)'
	includePreviewVersions: false

Note that the UseDotNet@2 task can pick up global.json to read its settings from - I would recommend to define these SDK settings only in global.json and not redefining it in the pipeline as well.

[TheCodeTraveler]

Thanks for updating the Analyzer Unit Tests, Shaun! We can just remove the reference to Net80 since we won't be reverting back to .NET 8 after we update the library to .NET 9.

[bijington]

The errors are because in https://github.com/CommunityToolkit/Maui/blob/feature/sl-dotnet-nine/azure-pipelines.yml the .NET SDK to install is

• set to the LATEST_NET_VERSION variable instead of picking up the version from global.json
• set to prevent using prereleases (both in global.json and in azure-pipelines.yml)

See

Maui/azure-pipelines.yml

Lines 73 to 78 in c4169ed

	- task: UseDotNet@2
	displayName: 'Install Latest .NET SDK, v$(LATEST_NET_VERSION)'
	inputs:
	packageType: 'sdk'
	version: '$(LATEST_NET_VERSION)'
	includePreviewVersions: false

Note that the UseDotNet@2 task can pick up global.json to read its settings from - I would recommend to define these SDK settings only in global.json and not redefining it in the pipeline as well.

Thanks for the suggestions. I know we have been discussing about migrating to GitHub actions so I will leave this with limited change for now

[bijington]

We have all check building thanks to @jfversluis for the workaround. I propose we add the workaround into the release notes

[ne0rrmatrix]

With the latest changes it builds. But clicking on menu's does not work. App loads but I cannot click on navigation link to test any functionality. I have tried the usual dotnet clean and deleting bin/obj folders. It builds and runs but I cannot navigate to any pages from Main Page. This is specific to Mac Catalyst on Mac Mini M2.

edit: After further investigation this is a Release mode issue and debug mode works fine. So possibly another release mode issue if anyone can confirm? Page navigation appears to be non functional in sample app in release mode.