Xamarincommunitytoolkit: [Bug] Expander - System.ArgumentException: 'NaN is not a valid value for Height'

[SirJohnK]

Description

When tapping the Expander header, mostly in rapid order, I get a System.ArgumentException 'NaN is not a valid value for Height'.

Steps to Reproduce

1. ContentPage with a Grid with a ScrollView with a StackLayout with BindableLayout.ItemsSource.
2. BindableLayout.ItemTemplate with a DataTemplate with the Expander control.
3. ItemSource has multiple items.
4. Tap First Expander Header, then second Expander header.
5. I get NaN is not a valid value for Height'.

Expected Behavior

Not getting System.ArgumentException when tapping Expander Header.

Actual Behavior

Sometimes getting the 'NaN is not a valid value for Height' System.ArgumentException.

Basic Information

• Version with issue: 4.6.0.726
• Last known good version: 4.6.0.726
• IDE: Visual Studio 2019 16.5.4
• Platform Target Frameworks: Android, iOS
  
  
  
  • iOS: 13.16.0.13
  
  
  • Android: 10.2.0.100
  
  
• Affected Devices: Android

Workaround

No workaround.

Tried:

• Removing CollectionView
• Setting MinimumHeightRequest
• Trigger ForceUpdateSizeCommand with Expander Header Command

[SirJohnK]

Found a potential workaround.
Before: <Expander CollapseAnimationLength="0" ExpandAnimationLength="0">
Workaround: <Expander CollapseAnimationLength="10" ExpandAnimationLength="10">

[rmarinho]

Hi @SirJohnK we moved the Expander for the XamarinFommunityToolkit, so i moved your issue here to be better tracked.

[AndreiMisiukevich]

Found a potential workaround.
Before: <Expander CollapseAnimationLength="0" ExpandAnimationLength="0">
Workaround: <Expander CollapseAnimationLength="10" ExpandAnimationLength="10">

Hi) Thanks for the report
So the bug occurs only with zero animation length, right?

[SirJohnK]

Found a potential workaround.
Before: <Expander CollapseAnimationLength="0" ExpandAnimationLength="0">
Workaround: <Expander CollapseAnimationLength="10" ExpandAnimationLength="10">

Hi) Thanks for the report
So the bug occurs only with zero animation length, right?

Yes, it seems like it. I wanted a non animation expansion, but a really low "AnimationLength" will also do the trick! 👍

[AndreiMisiukevich]

Then We should coerce the value to be not less than 1)

[jfversluis]

Will you take this @AndreiMisiukevich? You can definitely say no of course. Just making sure that not everyone is waiting for you to do it

[AndreiMisiukevich]

Will you take this @AndreiMisiukevich? You can definitely say no of course. Just making sure that not everyone is waiting for you to do it

I will do it

[jfversluis]

You are just waiting for October so you can join in Hacktoberfest... 😝