Frame offsets inner content view by 1pt

[filipnavara]

Description

The Frame control implements the IBorderElement interface and unconditionally returns IBorderElement.BorderWidth => 1 whether the border is visible or not. The default color for the border is null.

In Xamarin.Forms you could make a round frame by instantiation Frame with IsClippedToBounds = true, CornerRadius = N/2, WidthRequest = N, HeightRequest = N (roughly) and the inner content view set to the Content property would be clipped to a circle.

In MAUI, however, the inner view is offset by the IBorderElement.BorderWidth during layout. If you set BackgroundColor to Colors.Tan and then the background of the inner content to something else, you'll notice that the "border area" remains tan despite the frame having no border set.

Example of the visual artifact:

Steps to Reproduce

No response

Link to public reproduction project repository

No response

Version with bug

8.0.61 SR6.1

Is this a regression from previous behavior?

Yes, this used to work in Xamarin.Forms

Last version that worked well

Unknown/Other

Affected platforms

iOS, Android

Affected platform versions

No response

Did you find any workaround?

Yes, implement IBorderElement.BorderWidth in our control derived from Frame and return 0.

Relevant log output

No response

[github-actions]

Hi I'm an AI powered bot that finds similar issues based off the issue title.

Please view the issues below to see if they solve your problem, and if the issue describes your problem please consider closing this one and thumbs upping the other issue to help us prioritize it. Thank you!

Open similar issues:

• Frame not using full width of the parent (StackLayout) when another element occupies the stack (#13488), similarity score: 0.77

Closed similar issues:

• Frame does not support BorderWidth (#15851), similarity score: 0.80
• Border is not displayed when inside a Frame in .net 8 (#19726), similarity score: 0.79
• Regression Android: Border in a Frame results in an empty Frame (#18922), similarity score: 0.79
• [regression/8.0.0] [Android] Border inside frame cause dont render content (#18526), similarity score: 0.76

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[PureWeen]

@filipnavara TBH this probably won't get scheduled any time soon.

We're marking Frame as obsolete in .NET9 so that's where we'll be putting most of our effort

[filipnavara]

I filed the issue mostly to make it easy to search for a workaround, and I don’t expect it to get any prioritisation at all. Once I figured the root cause the workaround was just 8 lines of code in our project.