Factory: load types by using reflection

WidgetFactory.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;

namespace WidgetApp
{
    /// <summary>
    /// Simple factory that creates a widget based on its name 
    /// </summary>
    public class WidgetFactory
    {
        private Dictionary<string, Type> widgets;

        /// <summary>
        /// Load widget types available
        /// </summary>
        public WidgetFactory()
        {
            LoadTypesICanRun();
        }

        /// <summary>
        /// Creates a new widget instance 
        /// </summary>
        /// <param name="widgetName">Widget name</param>
        /// <returns>Widget</returns>
        public IWidget CreateInstance(string widgetName)
        {
            IWidget widgetToReturn;

            Type t = GetTypeToCreate(widgetName);

            if (t == null)
                throw new ArgumentException("No widget found!");
            else
                widgetToReturn = Activator.CreateInstance(t) as IWidget;

            return widgetToReturn;
        }

        /// <summary>
        /// Checks if widget Type exists and returns it
        /// </summary>
        /// <param name="widgetName">Widget name</param>
        /// <returns>Widget Type</returns>
        private Type GetTypeToCreate(string widgetName)
        {
            Type widgetType = null;
            foreach (var widget in widgets)
            {
                if (widget.Key.Contains(widgetName.ToLower()))
                {
                    widgetType = widgets[widget.Key];
                    break;
                }
            }
            return widgetType;
        }

        /// <summary>
        /// Loads all IWidget types from this assembly
        /// </summary>
        private void LoadTypesICanRun()
        {
            widgets = new Dictionary<string, Type>();

            Type[] typesInThisAssembly = Assembly.GetExecutingAssembly().GetTypes();

            foreach (Type t in typesInThisAssembly)
            {
                if (t.GetInterface(typeof(IWidget).ToString()) != null)
                    widgets.Add(t.Name.ToLower(), t);
            }
        }
    }
}