StaticResourceExtension : need to implément IXamlSchemaContextProvider in design time

Question

Hi all,

I use a bindable static resource extension that inherit from StaticResourceExtension.

It's work in run time, so very well.

But in design time, I have the error : The markup extension 'BindableStaticResource' require that 'IXamlSchemaContextProvider' is implemented in the IServiceProvider of ProvideValue.  

See the BindableStaticResourceExtension code:

using System;
using System.Windows;
using System.Windows.Data;
using System.Windows.Markup;
using System.Xaml;

namespace WinningGames.Core
{
	/// <summary>
	/// Define a bindable static resource
	/// </summary>
	public class BindableStaticResource : StaticResourceExtension
	{
		private bool dataContextChangeHandlerSet = false;
    /// <summary>
		/// Create a bindable static resource
		/// </summary>
		public BindableStaticResource()
			: base()
		{
			Binding = new Binding();
		}

		/// <summary>
		/// Create a bindable static resource
		/// </summary>
		/// <param name="binding">Binding used to retrive the resource key</param>
		public BindableStaticResource(Binding binding)
			: base()
		{
			Binding = binding;
		}

		/// <summary>
		/// Provide a value for the target property
		/// </summary>
		/// <param name="serviceProvider">Service provider for the markup extension</param>
		/// <returns>Value for the target property</returns>
		public override object ProvideValue(IServiceProvider serviceProvider)
		{
      // Get the service
			IProvideValueTarget provideValueTarget = serviceProvider.GetService(typeof(IProvideValueTarget)) as IProvideValueTarget;
			if(provideValueTarget != null)
			{
				// Get the target element
				FrameworkElement targetElement = provideValueTarget.TargetObject as FrameworkElement;
        /* if (targetElement == null)
          targetElement = provideValueTarget.TargetObject as FrameworkElement;*/
				if(targetElement != null)
				{
					// If the data context change handler has not been setted
					if(!dataContextChangeHandlerSet)
					{
						// Add an handler
						targetElement.DataContextChanged += new DependencyPropertyChangedEventHandler(targetElement_DataContextChanged);
						dataContextChangeHandlerSet = true;
					}

					// If the binding has none source
					if(String.IsNullOrEmpty(Binding.ElementName) && Binding.RelativeSource == null && Binding.Source == null)
						// Use the datacontext of the target
						Binding.Source = targetElement.DataContext;
				}
			}

			// Create a dummy object to simulate the binding
			DependencyObject dummyObject = new DependencyObject();
			// Set the dummy binding
			BindingOperations.SetBinding(dummyObject, DummyProperty, Binding);
			// Get the binded value and use it as resource key
			this.ResourceKey = dummyObject.GetValue(DummyProperty);
			// Return the resource
			return ResourceKey != null ? base.ProvideValue(serviceProvider) : null;
		}

		/// <summary>
		/// Get or set the resource key
		/// </summary>
		public new object ResourceKey
		{
			get
			{
				return base.ResourceKey;
			}
			set
			{
				// We accept a null value without set it
				if(value != null)
					base.ResourceKey = value;
			}
		}

		/// <summary>
		/// Get or set the binding used to retrieve the resource key
		/// </summary>
		public Binding Binding { get; set; }

		/// <summary>
		/// Occurs when the datacontext of the target object has changed
		/// </summary>
		/// <param name="sender">Event sender</param>
		/// <param name="e">Event argument</param>
		private void targetElement_DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
		{
      /*Binding = new Binding();
      Binding.Path = new PropertyPath("Name");
      ProvideValue(serviceProvider);*/
			// TODO : Call the ProvideValue method
		}

		/// <summary>
		/// Dummy property used to simulate the binding
		/// </summary>
		private static readonly DependencyProperty DummyProperty = DependencyProperty.Register("Dummy", typeof(object), typeof(DependencyObject));
	}
}

and the use :

<UserControl x:Class="WinningGames.PieceView"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
  mc:Ignorable="d"
	xmlns:core="clr-namespace:WinningGames.Core"
	Height="45" Width="45" 
  DataContext="{Binding Piece, Source={StaticResource Locator}}"
  Grid.Column="{Binding X}" Grid.Row="{Binding Y}">
  <UserControl.Resources>
		<ResourceDictionary Source="Resources/ResourceDictionary.xaml" />
  </UserControl.Resources>
  <UserControl.Content>
		<core:BindableStaticResource Binding="{Binding Name}" />
  </UserControl.Content>
</UserControl>

 

Have you an idea to help me?

 

Thanks