[regression/7.0.96] Picker is empty on mac catalyst

[singhwong]

Description

Picker is empty on mac catalyst, no list is displayed, just a pop-up window.

Steps to Reproduce

1. Create a file>New .Net MAUI App
2. Add sample code to MainPage

<Picker x:Name="picker"
        Title="Select a monkey">
  <Picker.ItemsSource>
    <x:Array Type="{x:Type x:String}">
      <x:String>Baboon</x:String>
      <x:String>Capuchin Monkey</x:String>
      <x:String>Blue Monkey</x:String>
      <x:String>Squirrel Monkey</x:String>
      <x:String>Golden Lion Tamarin</x:String>
      <x:String>Howler Monkey</x:String>
      <x:String>Japanese Macaque</x:String>
    </x:Array>
  </Picker.ItemsSource>
</Picker>

3. Click the Picker

Link to public reproduction project repository

No response

Version with bug

7.0.96

Is this a regression from previous behavior?

Yes, this used to work in .NET MAUI

Last version that worked well

Unknown/Other

Affected platforms

macOS

Affected platform versions

macOS Sonoma 14.0

Did you find any workaround?

No response

Relevant log output

No response

[samhouts]

Thank you for the report! You said that this used to work on an unknown version. Was this working in .NET 7?

Hi @singhwong. We have added the "s/needs-info" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[singhwong]

This issue occurs when using MacOS Sonoma 14 + .net7 7.0.400 + maui 7.0.96 or MacOS Sonoma 14 + .net8 8.0.100-rc.2.23502.2 + maui 8.0.0-rc.2.9373, and what I can be sure of is that when using the previous version of maui (maui 7.0.92) + the previous version of macOS (not sonoma), working properly.

[drasticactions]

As far as I can tell This will be happening regardless of the version of MAUI being used, going by how the underlying control is written:

https://github.com/dotnet/maui/blob/main/src/Core/src/Handlers/Picker/PickerHandler.iOS.cs#L41

The Maui Picker is a wrapper around a UITextField that fires a UIAlert to show a picker. That code doesn't work on Sonoma, it'll just show the alert. There's probably gonna need to be some rethinking around how that control works.

e.

https://github.com/dotnet/maui/blob/net7.0/src/Core/src/Handlers/Picker/PickerHandler.iOS.cs#L73C3-L79

So I believe the way this worked was by using UITextView. When you tapped it, it will fire an event on edit to create a UIAlertController with an ActionSheet style, and hijack it by replacing its underlying view with a UIPickerView instead. My guess is that, while possible since the View is publicly exposed, it's against the spirit of the control and that broke with Sonoma and/or Xcode so it actually shows the Alert now. @rolfbjarne would you have any ideas for this? It seems like how this is written was kinda fragile.