Why this property isn't visible? Says attachable property can't be found

Question

I'm creating Behavior with attached properties. Behavior should attach to Grid:

public class InteractionsBehavior : Behavior<Grid>
{
    public static readonly DependencyProperty ContainerProperty =
        DependencyProperty.RegisterAttached("Container", typeof(Grid), typeof(Grid), new PropertyMetadata(null));

    public static readonly DependencyProperty InteractionsProviderProperty =
        DependencyProperty.RegisterAttached("InteractionsProvider", typeof(IInteractionsProvider), typeof(Grid), new PropertyMetadata(null, OnInteractionsProviderPropertyChanged));

    public Grid Container
    {
        get { return GetValue(ContainerProperty) as Grid; }
        set { this.SetValue(ContainerProperty, value); }
    }

    public IInteractionsProvider InteractionsProvider
    {
        get { return GetValue(InteractionsProviderProperty) as IInteractionsProvider; }
        set { this.SetValue(InteractionsProviderProperty, value); }
    }

Now when I'm writing XAML like this I get error:

<Grid Background="White" x:Name="LayoutRoot" 
          Behaviors:InteractionsBehavior.InteractionsProvider="{Binding InteractionsProvider}">

Error 4 The property 'InteractionsProvider' does not exist on the type 'Grid' in the XML namespace 'clr-namespace:Infrastructure.Behaviors;assembly=Infrastructure.SL'. C:\MainPage.xaml 11 11 Controls.SL.Test

Error 1 The attachable property 'InteractionsProvider' was not found in type 'InteractionsBehavior'. C:\MainPage.xaml 11 11 Controls.SL.Test

Reed Copsey Reed Copsey · Accepted Answer · 2011-11-14T21:27:20

You specified that it only should be available to be attached ("owned") by an InteractionsBehavior. If you want to be able to assign this to a grid, change the RegisterAttached line to:

public static readonly DependencyProperty InteractionsProviderProperty =
        DependencyProperty.RegisterAttached("InteractionsProvider", typeof(IInteractionsProvider), typeof(Grid), new PropertyMetadata(null, OnInteractionsProviderPropertyChanged));

(Or use some base class in Grid's class hierarchy...)

Why this property isn't visible? Says attachable property can't be found

2 Answers