iOS/Mac Catalyst image localization

[davidbritch]

Description

The technique for localizing images on iOS are well known. It involves creating folders with the locale name, followed by .lproj, with the images in these folders. These would normally go in a Resources folder. So for MAUI I translated this to the Platforms\iOS\Resources folder:

The images have a build action of BundleResource.

This doesn't work for iOS, or on Mac Catalyst (using the equivalent MacCatalyst folder).

What does work is putting the .lproj folders in the root of the MAUI project:

Localized images are then displayed (on both iOS + MacCat).

While it works it makes me feel dirty having the root of your project contaminated with Apple only resources.

UPDATE: @rolfbjarne has told me that updating the .csproj to include <IPhoneResourcePrefix>Platforms/iOS/Resources</IPhoneResourcePrefix> makes localised images, contained in that specific folder, work on iOS + MacCat.

Steps to Reproduce

1. Run attached sample on iOS.

Link to public reproduction project repository

https://github.com/davidbritch/dotnet-maui-issues/tree/main/LocalizationDemo

Version with bug

7.0.92

Is this a regression from previous behavior?

Don't think this has ever worked!

Affected platforms

iOS, macOS

Did you find any workaround?

Place .lproj folders in the root of your MAUI project.

OR (better)

Update your .csproj with the following:

	<PropertyGroup Condition="$(TargetFramework.Contains('-ios'))">
		<IPhoneResourcePrefix>Platforms/iOS/Resources</IPhoneResourcePrefix>
	</PropertyGroup>

	<PropertyGroup Condition="$(TargetFramework.Contains('-maccatalyst'))">
		<IPhoneResourcePrefix>Platforms/MacCatalyst/Resources</IPhoneResourcePrefix>
	</PropertyGroup>

[rolfbjarne]

MAUI already sets IPhoneResourcePrefix, but it happens too late:

maui/src/Controls/src/Build.Tasks/nuget/buildTransitive/netstandard2.0/Microsoft.Maui.Controls.SingleProject.targets

Line 46 in e36d222

<IPhoneResourcePrefix>$(iOSProjectFolder)Resources</IPhoneResourcePrefix>

maui/src/Controls/src/Build.Tasks/nuget/buildTransitive/netstandard2.0/Microsoft.Maui.Controls.SingleProject.targets

Line 52 in e36d222

<IPhoneResourcePrefix>$(MacCatalystProjectFolder)Resources</IPhoneResourcePrefix>

[rolfbjarne]

In particular it must happen before Xamarin.Shared.props is imported in line 211 here:

https://gist.github.com/rolfbjarne/b194bc4d4d345425eee1a17fc0523ab6#file-gistfile1-txt-L211

currently it happens in Microsoft.Maui.Controls.SingleProject.targets at line 246:

https://gist.github.com/rolfbjarne/b194bc4d4d345425eee1a17fc0523ab6#file-gistfile1-txt-L246

[ghost]

We've added this issue to our backlog, and we will work to address it as time and resources allow. If you have any additional information or questions about this issue, please leave a comment. For additional info about issue management, please read our Triage Process.

[XamlTest]

Verified this on Visual Studio Enterprise 17.8.0 Preview 1.0. Repro on iOS 16.4 and Windows 11 .NET 8, not repro on Android 13.0-API33 with below Project:
LocalizationDemo.zip

iOS:

Android:

[ArchimedesFTW]

@davidbritch does localization of Info.plist work for you with your proposed workaround?

I want to ask for location permission with localized text.

I moved fr.lproj to the project root to get the flag visible on iOS. I added InfoPlist.strings in that folder but it won't show the different text. Instead it shows the text that I added in the Info.plist.

Any suggestions?

[davidbritch]

@ArchimedesFTW It worked for me at the time of writing. But there've been multiple releases since then, and I've not tried it since.

[janusw]

@davidbritch does localization of Info.plist work for you with your proposed workaround?

I want to ask for location permission with localized text.

FYI, I got the permission localization working by placing the lproj folders here (with MAUI 8.0.14):

	<ItemGroup Condition="'$(TargetFramework)'=='net8.0-ios'">
		<BundleResource Include="Resources\de.lproj\InfoPlist.strings" />
	</ItemGroup>

[janusw]

FYI, I got the permission localization working by placing the lproj folders here (with MAUI 8.0.14):

	<ItemGroup Condition="'$(TargetFramework)'=='net8.0-ios'">
		<BundleResource Include="Resources\de.lproj\InfoPlist.strings" />
	</ItemGroup>

Note that this location is slightly different from the one in the workaround mentioned in the original report (i.e. I'm placing the lproj folders into Resources, and not directly into the root folder).

Also, I can confirm that the second workaround works well with permission localization: If the lproj folders are in Platforms\iOS\Resources, you need the additional

<IPhoneResourcePrefix>Platforms/iOS/Resources</IPhoneResourcePrefix>

in your csproj.

[tdamir]

In my case a working solution is to move files from Platforms/iOS/Resources to root/Resources folder OR move them to Resources/raw but then there is no need for <BundleResource> include.

Keeping the files in Platforms/iOS/Resources and adding the <IPhoneResourcePrefix>Platforms/iOS/Resources</IPhoneResourcePrefix> did't work for me. When I tried to publish/archive the project, it complained about not finding a generated Info.Plist file. Also, I have noticed that there were some warnings/errors like "The given path's format is not supported" or something like that while building the project.

I'm using Visual Studio Version 17.10.0 Preview 3.0. and MAUI 8.0.14.