iOS app crashes when calling GetValue on Virtual Property

[PureWeen]

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Issue moved from dotnet/maui#26707

• Please respond to @MDThomsen.

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From @MDThomsen on Wednesday, December 18, 2024 2:24:48 PM

I am working with a maui app that in some instances relies on getting values through reflection.
There is a specific case where a base class has a virtual property, which is then overridden in a parent class.

In the reproduction project there is a base page with:
public virtual bool IsVisible => true;

and then a page that inherits from that base page, which then overrides the property as such:
public override bool IsVisible => true;

When creating an instance of PropertyInfo on the overriden property with
var visibleBindingPropertyInfo = GetType().GetTypeInfo().GetRuntimeProperty(nameof(IsVisible));

and then calling GetValue by
if (visibleBindingPropertyInfo != null) isVisible = (bool)visibleBindingPropertyInfo.GetValue(this);

causes the iOS app to crash.

The crash occurs when the interpreter is disabled like so;
<MtouchInterpreter>-all</MtouchInterpreter>

If the Interpreter is enabled, then it will not crash. However using the Interpreter is not an option in my case, as it downgrades the performance too much for a production build.

The crash started occurring after updating to VS 2022 with the following workload list:

Installed Workload Id      Manifest Version       Installation Source
---------------------------------------------------------------------
aspire                     8.2.2/8.0.100          VS 17.11.35431.28
maui-windows               8.0.82/8.0.100         VS 17.11.35431.28
maccatalyst                18.0.8303/8.0.100      VS 17.11.35431.28
ios                        18.0.8303/8.0.100      VS 17.11.35431.28
android                    34.0.113/8.0.100       VS 17.11.35431.28

However on the previous installation of visual studio with the following workload list, it is working without crashing:

Installed Workload Id      Manifest Version       Installation Source
---------------------------------------------------------------------
maui-windows               8.0.40/8.0.100         VS 17.10.35013.160
maccatalyst                17.2.8053/8.0.100      VS 17.10.35013.160
ios                        17.2.8053/8.0.100      VS 17.10.35013.160
android                    34.0.95/8.0.100        VS 17.10.35013.160

I also noticed this ticket dotnet/runtime#96611 which mentions something similar, however that is older than the release of 8.0.40 in which it was working.

Steps to Reproduce

1. Run the reproduction project on a real iOS device (not simulator).
2. Press the "Click me" button on the main page.
3. Crash

Link to public reproduction project repository

https://github.com/MDThomsen/BindingCrash.git

Version with bug

8.0.82 SR8.2

Is this a regression from previous behavior?

Yes, this used to work in .NET MAUI

Last version that worked well

8.0.40 SR5

Affected platforms

iOS

Affected platform versions

18.0.8303/8.0.100

Did you find any workaround?

No response

Relevant log output