BUG: FontAttributes="Bold" on iOS has no effect in .NET MAUI (x .NET 9.0)

[Auto72]

Description

The following XAML code doesn't set bold the text label on iOS:

<Label Text="Hello, World Bold!" HorizontalOptions ="Fill" FontAttributes="Bold" />

iOS (18.4)

Android

Windows

Workaround:

        <Label x:Name="Label2Span">
            <Label.FormattedText>
                <FormattedString>
                    <Span Text="Hello, World Bold Workaround (FormattedText)" FontAttributes="Bold"/>
                </FormattedString>
            </Label.FormattedText>
        </Label>

Steps to Reproduce

Get the example here and run it on iOS
https://github.com/Auto72/MauiAppBoldTest

Link to public reproduction project repository

https://github.com/Auto72/MauiAppBoldTest

Version with bug

9.0.60 SR6

Is this a regression from previous behavior?

Not sure, did not test other versions

Last version that worked well

No response

Affected platforms

iOS

Affected platform versions

No response

Did you find any workaround?

No response

Relevant log output

[similar-issues-ai]

We've found some similar issues:

• HTML Label not applying Bold or Italics on iOS #20372 , similarity score: 82%
• [iOS]The "FontAttributes" property of label is not rendered on ios and maccatalyst. #7574 , similarity score: 82%

If any of the above are duplicates, please consider closing this issue out and adding additional context in the original issue.

Note: You can give me feedback by 👍 or 👎 this comment.

[HarishKumarSF4517]

This issue has been verified in VS code (1.99.2) (versions 9.0.60, 9.0.0 & 8.0.100). It can be reproduced on the iOS and MacCatalyst platforms and not reproduced on the Android and Windows platforms.

[bobwhitten]

I found the following "work-around", of sorts.

The in the template, MauiProgram.cs has the following two lines:

                fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
                fonts.AddFont("OpenSans-Semibold.ttf", "OpenSansSemibold"); 

I found that if I exclude these, at least for iOS (and presumably MacCatalyst), all my font attribute issues magically vanish.

Apparently these fonts do not support italic or bold. Allowing the app to default to the standard fonts is the key.

I can't remember where I figured this out, or I would give some attribution.

[Auto72]

@bobwhitten
You are right, these fonts do not support italic or bold and if we don't add them for IOS and MACCATALYST,
the system fonts will be used instead and they do support bold and italic.

            .ConfigureFonts(fonts =>
            {
#if IOS || MACCATALYST
#else
                fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");           // Default font .NET MAUI
                fonts.AddFont("OpenSans-Semibold.ttf", "OpenSansSemibold");         // Default font .NET MAUI
#endif
            });

It is a working workaround.

Thanks.