[RC1] Label MaxLines doesn't work

[ram16g]

Description

When set LineBreakMode，MaxLines doesn't work, it always show one line

Steps to Reproduce

<Label Text="Welcome to .NET Multi-platform App UI Welcome to .NET Multi-platform App UI ET Multi-platform App UI ET Multi-platform App UI ET Multi-platform App UI ET Multi-platform App UI Welcome to .NET Multi-platform App UI Welcome to .NET Multi-platform App UI Welcome to .NET Multi-platform App UI Welcome to .NET Multi-platform App UI" SemanticProperties.HeadingLevel="Level1" SemanticProperties.Description="Welcome to dot net Multi platform App U I" MaxLines="3" LineBreakMode="TailTruncation" FontSize="18" HorizontalOptions="Center" />

Version with bug

Release Candidate 1

Last version that worked well

Unknown/Other

Affected platforms

Android

Affected platform versions

ANDROID 10

Did you find any workaround?

no

Relevant log output

NO

[hartez]

@ram16g Are you seeing this on Android, or on a different platform? On Android, TailTruncation (and the other truncation options) does not support multiple lines.

To be clear - the Android platform does support TailTruncation (TextUtils.TruncateAt.END) with multiple lines; for backward compatibility reasons, MAUI.Controls does not support combining multiple lines with TailTruncation. However, it's possible to customize the mapping behavior to support that combination. I'll try to post a demo of how to do that tomorrow.

[kristinx0211]

verified exist on Android 11. show one line.

[ram16g]

@ram16g Are you seeing this on Android, or on a different platform? On Android, TailTruncation (and the other truncation options) does not support multiple lines.

To be clear - the Android platform does support TailTruncation (TextUtils.TruncateAt.END) with multiple lines; for backward compatibility reasons, MAUI.Controls does not support combining multiple lines with TailTruncation. However, it's possible to customize the mapping behavior to support that combination. I'll try to post a demo of how to do that tomorrow.
n't
This PR pr #5093 supposed to fix this bug,however it still doesn't work.

[hartez]

Example of how to customize your app to support multiple line Labels with TailTruncation: https://github.com/hartez/MultilineTruncate

[kasimier-vireq]

@hartez : In the example we read "This is a backward-compatibility carryover from Xamarin.Forms" and "However, Android does support some truncation modes ("Ellipsize", on Android) for multiple lines, and TailTruncation (TextUtils.TruncateAt.End on Android) is one of them".

Wouldn't it be better to provide an opt-in for backwards Xamarin.Forms compatibility instead?
If MAUI wants to be a fresh start, then why carry over bugs from Xamarin.Forms?

[hartez]

Wouldn't it be better to provide an opt-in for backwards Xamarin.Forms compatibility instead?
If MAUI wants to be a fresh start, then why carry over bugs from Xamarin.Forms?

Because we don't want to prevent current Forms users from easily moving to MAUI.Controls.

Long term, we intend to update how MAUI.Core handles text wrapping, truncation, and multiple lines - see #5835. And once that happens, users will have an option to get the new behavior or keep the old one.