Blazor can't use EventCallback with array TypeParam value

[omuleanu]

I've isolated my issue to a small bit of code, having a component like this:

MyArrValComp.razor

@typeparam TKey
@code {
    [Parameter]
    public TKey[] Value { get; set; }

    [Parameter]
    public EventCallback<TKey[]> ValueChanged { get; set; }
}

I call the component like in Index.razor like this:

<MyArrValComp @bind-Value="val1" TKey="int"/>
@code
{
    private int[] val1 = new []{ 1, 2, 3 };
}

and it won't compile, it will give misleading error messages like this:
The type or namespace name 'TKey' could not be found (are you missing a using directive ... Index.razor.g.cs
The type or namespace name 'TKey' could not be found (are you missing a using ... Index.razor

after experimentation I realized that Arrays won't work with EventCallback I need to use IEnumerable<T> instead, that fixed it.

---

1. so the error messages are definitely misleading,
2. also not sure if you're aware about this issue, I haven't noticed in the docs saying that we can't use arrays with EventCallback
3. is it possible to bind to any collection, I was hoping since Value and ValueChanged are IEnumerable<T> I'll be able to bind to any collection (including T[] ) but no, it only accepts IEnumerable<T> ?

[mkArtakMSFT]

Thanks for contacting us. This seems to be similar to #9462

[TanayParikh]

@javiercn can this be moved over to razor-compiler or are there any blazor specific pieces here?

[mkArtakMSFT]

@omuleanu this might have been fixed already. Can you give it a try and if not, we'll move this to the razor-compiler repo.

[mkArtakMSFT]

I meant that this should be fixed in .NET 7.

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