ToolbarItem icon doesn't work with MVVM Binding on iOS

[AncientLust]

Description

ToolbarItem icon doesn't work with MVVM Binding on iOS

This doesn't work:

<ContentPage.ToolbarItems>
    <ToolbarItem>
        <ToolbarItem.IconImageSource>
            <FileImageSource File="{Binding FilterStatusIcon}" />
        </ToolbarItem.IconImageSource>
    </ToolbarItem>
</ContentPage.ToolbarItems>

public partial class MainPageVM : ObservableObject
{
    [ObservableProperty] private string filterStatusIcon = "filter";
}

While this one does:

<ContentPage.ToolbarItems>
    <ToolbarItem>
        <ToolbarItem.IconImageSource>
            <FileImageSource File="filter" />
        </ToolbarItem.IconImageSource>
    </ToolbarItem>
</ContentPage.ToolbarItems>

Steps to Reproduce

1. Open repro proj
2. Deploy to iOS device
3. Check that icon wasn't showed
4. Replace binding by direct icon name: File="{Binding FilterStatusIcon}" -> File="filter"
5. Redeploy, icon will appear

Link to public reproduction project repository

https://github.com/AncientLust/ToolBarItem-icon-binding-issue

Version with bug

8.0.6

Is this a regression from previous behavior?

Not sure, did not test other versions

Last version that worked well

Unknown/Other

Affected platforms

iOS

Affected platform versions

No response

Did you find any workaround?

No response

Relevant log output

No response

[ghost]

We've added this issue to our backlog, and we will work to address it as time and resources allow. If you have any additional information or questions about this issue, please leave a comment. For additional info about issue management, please read our Triage Process.

[PureWeen]

@AncientLust if you bind to the text does the text binding work?

[AncientLust]

@PureWeen but text binding is exactly what I attached above (File name binded with string property FilterStatusIcon).

Or I don't get the quesiton, what do you mean?

[JayMansel]

It's not due to the property casing is it? filterStatusIcon in your VM and FilterStatusIcon in your XAML?

[AncientLust]

@JayMansel naah, MVVM generates property with capital letter:

public string FilterStatusIcon
{
    get => filterStatusIcon;
    [global::System.Diagnostics.CodeAnalysis.MemberNotNull("filterStatusIcon")]
    set
    {
        if (!global::System.Collections.Generic.EqualityComparer<string>.Default.Equals(filterStatusIcon, value))
        {
            OnFilterStatusIconChanging(value);
            OnFilterStatusIconChanging(default, value);
            OnPropertyChanging(global::CommunityToolkit.Mvvm.ComponentModel.__Internals.__KnownINotifyPropertyChangingArgs.FilterStatusIcon);
            filterStatusIcon = value;
            OnFilterStatusIconChanged(value);
            OnFilterStatusIconChanged(default, value);
            OnPropertyChanged(global::CommunityToolkit.Mvvm.ComponentModel.__Internals.__KnownINotifyPropertyChangedArgs.FilterStatusIcon);
        }
    }
}

It even doesn't work with lower one: