WinAppSDK crash on startup when using most Material styles

[kazo0]

Installing latest dev templates with dotnet new install uno.templates::5.0.0-dev.486 and running dotnet new unoapp -o MyTestApp results in a crash on startup when running the Windows head:

With latest VS Stable and VS Preview

App starts fine if I use dotnet new unoapp -preset=blank -o MyTestApp

[nickrandolph]

This is a result of using the FilledButtonStyle on a Button

[kazo0]

The error is this:

Exception thrown at 0x00007FFB487A535C (KernelBase.dll) in MaterialTestApp.Windows.exe: WinRT originate error - 0x802B000A : 'Failed to assign to property 'Microsoft.UI.Xaml.UIElement.Visibility'. [Line: 0 Position: 0]'.

And it seems to be happening with any control that has this in the template:

Visibility="{Binding Path=(um:ControlExtensions.Icon), RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource MaterialNullToCollapsedConverter}, FallbackValue=Collapsed, TargetNullValue=Collapsed}"

It looks like there's been a change in winui surrounding this? Can no longer have the converter return a string of "Visible" or "Collapsed", if I instead make it return a Visiblity enum value or create Visibility StaticResources and set those as the properties of the converter then it works

<Visibility x:Key="VisibleVal">Visible</Visibility>
	<Visibility x:Key="CollapsedVal">Collapsed</Visibility>
	<local:MyConverter x:Key="MaterialNullToCollapsedConverter"
								 NotNullValue="{StaticResource VisibleVal}"
								 NullValue="{StaticResource CollapsedVal}" />

[Xiaoy312]

would it work if you used string literals "True" "False" directly on the converter's properties?

[kazo0]

@Xiaoy312

Using True/False doesn't cause a crash but it also doesn't work and just stays as Visible no matter what MyProp is.

So basically MyConverter3 is where the crash occurs

<Page x:Class="MaterialTestApp.MainPage"
	  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
	  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
	  xmlns:local="using:MaterialTestApp"
	  xmlns:um="using:Uno.Material"
	  xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
	  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
	  xmlns:maui="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
	  xmlns:not_maui="http://notmaui"
	  mc:Ignorable="d not_maui"
	  Background="{ThemeResource BackgroundBrush}">
	<Page.Resources>
		<Visibility x:Key="VisibleVal">Visible</Visibility>
		<Visibility x:Key="CollapsedVal">Collapsed</Visibility>
		
		<local:MyConverter x:Key="MyConverter1"
						   FalseValue="{StaticResource CollapsedVal}"
						   TrueValue="{StaticResource VisibleVal}" />

		<local:MyConverter x:Key="MyConverter2"
						   FalseValue="False"
						   TrueValue="True" />

		<local:MyConverter x:Key="MyConverter3"
						   FalseValue="Collapsed"
						   TrueValue="Visible" />
	</Page.Resources>
	<StackPanel HorizontalAlignment="Center"
				VerticalAlignment="Center">
		<Button Content="Toggle MyProp"
				Click="Button_Click" />
		
		<!--Works-->
		<CheckBox Content="Converter 1" Visibility="{Binding MyProp, Converter={StaticResource MyConverter1}}" />
		
		<!--Compiles but doesn't toggle Visibility-->
		<CheckBox Content="Converter 2" Visibility="{Binding MyProp, Converter={StaticResource MyConverter2}}" />
		
		<!--Crashes-->
		<CheckBox Content="Converter 3" Visibility="{Binding MyProp, Converter={StaticResource MyConverter3}}" />
	</StackPanel>
</Page>

[kazo0]

I'm curious why this started happening but since this looks like a WinAppSDK thing, I guess we should just create some sort of specific NullToVisibilityConverter and use that instead?

[kazo0]

After discussion, we will refactor the Uno.Themes repo to find any places where we are using a Converter with parameters for the Visiblity and instead use a new converter that is specific for Visibility that returns a strongly-typed Visibility enum

[Arieldelossantos]

only for Uno.Material?? or we need to do the replacement on the Uno.Cupertino styles?? @kazo0

[kazo0]

@Arieldelossantos on second thought, could you maybe spend some time trying to investigate why this crash is happening on Windows? I can't seem to get it to crash on Chefs or any other app that I update to the latest WinAppSdk version. You should be able to get it to crash by just doing
dotnet new install uno.templates::5.0.0-dev.486 (or any later -dev.X version)
dotnet new unoapp -preset blank -theme material -o MaterialTestApp -skip
and then adding a button to the MainPage.xaml of your sample app