Unable to register component event without ParameterAttribute

[fs86]

I noticed that events in custom components can only be registered from the parent component if ParameterAttribute is present. I have followed the example of @danroth27, which is described here: #5504

My custom component:

<input type="text" value="@Value" onchange="@OnInputChanged" />

@functions
{
    [Parameter] string Value { get; set; }
    public Action<string> ValueChanged { get; set; }
    void OnInputChanged(UIChangeEventArgs e)
    {
        Value = e.Value.ToString();
        ValueChanged(Value);
    }
}

My parent component:

<MyCustomComponent Value="@Product.Name" ValueChanged="@OnValueChanged" />

@functions
{
    void OnValueChanged(string value)
    {
        Product.Name = value;
        StateHasChanged();
    }
}

Output: "Cannot convert method group 'OnValueChanged' to non-delegate type 'object'. Did you intend to invoke the method?"

If I add [Parameter] to my event, everything works fine.

[chucker]

Since @danroth27's example is from before Blazor 0.3, my guess this is by design, since 0.3's release notes state:

Upgrade an existing project to Blazor 0.3.0
To upgrade an existing Blazor project from 0.2.0 to 0.3.0:
[..]
Update component parameters to not be public and to add the [Parameter] attribute.

[fs86]

Many thanks for your response. Then it's probably not a bug.

[SteveSandersonMS]

Thanks for answering, @chucker!