Array element type ignored by Xaml compiler

[TomEdwardsEnscape]

The method AvaloniaXamlIlLanguageParseIntrinsics.GetElementType only works for IEnumerable<T> types. To support arrays too, these lines should be added:

if (type.IsArray)
{
    return type.ArrayElementType;
}

Unfortunately this change won't have an immediate effect due to kekekeks/XamlX/issues/89, which causes ArrayElementType to return the wrong value.

However, once both of these bugs are fixed then Avalonia starts to support defining arrays with comma-delimited strings! e.g. MyIntArray="1,2,3" or MyDockArray="Top,Bottom,Top". This syntax is something that I wanted to write earlier today, but was unable to.

To Reproduce
Add an array property to a control, then try to assign a value to it in XAML. You will receive a compiler error that looks like this:

Avalonia error AVLN: 0004: XamlX.XamlLoadException: Unable to find suitable setter or adder for property [...] of type [...] for argument netstandard:System.String, available setter parameter lists are:

Expected behavior
Arrays can be defined in XAML with comma-delimited strings, using the same parsing rules as single values of the same type.

[maxkatz6]

However, once both of these bugs are fixed then Avalonia starts to support defining arrays with comma-delimited strings!

Side note, this syntax is already working at least with other kinds of collections, like IList or AvaloniaList.

[TomEdwardsEnscape]

Thanks for the tip. I can confirm that those two types work, but as far as I can tell only it's them and IReadOnlyList<T> which are supported. If the property is List<T> (the class), ICollection<T>, or even IEnumerable<T> then a compiler error is emitted instead.

[TomEdwardsEnscape]

To fix this bug, a change also has to be made to Avalonia. Or does it work already?

[timunie]

Would be great if anyone could try using nightly build.

/cc @TomEdwardsEnscape

[workgroupengineering]

#13328

[TomEdwardsEnscape]

It's not fixed yet, see the PR above.