为什么此属性不是'；不可见?说可扣押财产可以；找不到

我正在创建带有附加属性的Behavior。行为应附加到网格：

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); }
    }

现在，当我像这样写XAML时，我会得到错误：

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

错误4类型上不存在属性"InteractionsProvider"XML命名空间中的"Grid"'clr命名空间：Infrastructure.Behaviors；assembly=Infrastructure.SL'.C:''MainPage.xaml 11 11 Controls.SL.Test

错误1找不到可附加的属性"InteractionsProvider"in type"交互行为"。C： ''MainPage.xaml 11 11 Controls.SL测试

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