Navigating the different modules through a TreeView and ToolBar with Prism

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Media.Imaging;
using System.Windows.Data;
using System.Windows.Controls;

namespace NavInfrastructure
{
    public class StringToImage : IValueConverter
    {
        private static readonly StringToImage defaultInstance = new StringToImage();
        public static StringToImage Default { get { return defaultInstance; } }

        #region IValueConverter Members

        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            string path = (string)value;
            if (string.IsNullOrEmpty(path))
                //path = defaultPathToIcon;
                if (parameter != null)
                    path = parameter as string;
                else
                    path = "/NavInfrastructure;component/Images/folder.png";
            Image im = new Image();
            im.Source = new BitmapImage(new Uri(path, UriKind.Relative));
            im.Height = 20;
            im.Width = 20;
            return im;
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }

        #endregion
    }
}