Cannot assign property "Actions"

[ebicoglu]

Hi,

I've been using Behaviors without a problem until Xamarin.Forms v3.0.
When I updated to Xamarin Forms v3.0, I got the below exception

Cannot assign property "Actions": Property does not exist, or is not assignable, or mismatching type between value and property

MyView.xaml

  <ContentPage.Behaviors>
        <behaviors:EventHandlerBehavior EventName="Appearing">
            <behaviors:InvokeCommandAction Command="{Binding PageAppearingCommand}" />
        </behaviors:EventHandlerBehavior>
    </ContentPage.Behaviors>

MyViewModel.cs

public ICommand PageAppearingCommand => new Command(async () =>
{
    await PageAppearingAsync();
});

[marcominerva]

I have the same issue too. Using the sample from this repo, with Xamarin.Forms v2.5.1.527436, everything works like a charm. As soon as I update it to 3.0.0.446417 (in all the projects), I get the "Cannot assign property Actions" error (even after a clean & rebuild).

[davidbritch]

Thanks for letting me know. I'll look into it.

[MaxenceMax]

Same for me since few days and update.

[davidbritch]

A temporary fix, to unblock people, is to explicitly declare an ActionCollection around the actions:

<ListView x:Name="listView" ItemsSource="{Binding People}">
    <ListView.Behaviors>
        <behaviors:EventHandlerBehavior EventName="ItemSelected">
            <behaviors:ActionCollection>
                <behaviors:InvokeCommandAction Command="{Binding ItemSelectedCommand}" Converter="{StaticResource SelectedItemConverter}" />
                <behaviors:InvokeCommandAction Command="{Binding OutputAgeCommand}" Converter="{StaticResource SelectedItemConverter}" />
            </behaviors:ActionCollection>
        </behaviors:EventHandlerBehavior>
    </ListView.Behaviors>
</ListView>

In the meantime, I'll work on fixing this.

[davidbritch]

This is now fixed, but I'm taking the opportunity to add a couple of extra bits of new functionality, so it'll be the end of the week before updated source code/NuGet is pushed live.

[davidbritch]

This is now fixed in v1.4.0 of the NuGet package.

[sgrassie]

I know this issue is closed, but I'm still having exactly the same problem, using 1.4.0 and Xamarin.Forms 3.1.0.637273. The given work around still works, so not blocked.

Seems I was too hasty in my previous assertion, cleaning the project and restarting VS seems to have sorted things out

[sgrassie]

Sorry, it seems that I can't get it work. Everything compiles, but the commands don't react to the events, e.g. the Appearing event doesn't fire the command I've bound to it.

[davidbritch]

@sgrassie

Have you get a small repo case for this (ZIP ideally)?

[davidbritch]

I've just created two new projects:

1. .NET Standard based Forms app.
2. PCL based Forms app.

In both cases I was able to install v1.4 of the Behaviors library, and use it to invoke commands in view models.

Without a firm repo case there's nothing more I can do about this.

[UnreachableCode]

I seem to be getting the same problem in a .NETStandard project with Xamarin Forms 3.2. I will post a repo reproducing the issue when I can.

@sgrassie I have the same issue. Were you able to fix it?