ObservableDictionary para Silverlight

He reutilizado copiado el código del Blog de Shimmy pero he tenido que modificarlo un poco para que encajase en Silverlight. De momento solo lo he usado en uno de mis proyectos pero funciona bastante bien.

using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Linq;

namespace SLUtils.Classes
{
        public class ObservableDictionary<TKey, TValue> : IDictionary<TKey, TValue>, INotifyCollectionChanged, INotifyPropertyChanged
        {
            private const string CountString = "Count";
            private const string IndexerName = "Item[]";
            private const string KeysName = "Keys";
            private const string ValuesName = "Values";

            private IDictionary<TKey, TValue> _Dictionary;
            protected IDictionary<TKey, TValue> Dictionary
            {
                get { return _Dictionary; }
            }

            #region Constructors
            public ObservableDictionary()
            {
                _Dictionary = new Dictionary<TKey, TValue>();
            }
            public ObservableDictionary(IDictionary<TKey, TValue> dictionary)
            {
                _Dictionary = new Dictionary<TKey, TValue>(dictionary);
            }
            public ObservableDictionary(IEqualityComparer<TKey> comparer)
            {
                _Dictionary = new Dictionary<TKey, TValue>(comparer);
            }
            public ObservableDictionary(int capacity)
            {
                _Dictionary = new Dictionary<TKey, TValue>(capacity);
            }
            public ObservableDictionary(IDictionary<TKey, TValue> dictionary, IEqualityComparer<TKey> comparer)
            {
                _Dictionary = new Dictionary<TKey, TValue>(dictionary, comparer);
            }
            public ObservableDictionary(int capacity, IEqualityComparer<TKey> comparer)
            {
                _Dictionary = new Dictionary<TKey, TValue>(capacity, comparer);
            }
            #endregion

            #region IDictionary<TKey,TValue> Members

            public void Add(TKey key, TValue value)
            {
                Insert(key, value, true);
            }

            public bool ContainsKey(TKey key)
            {
                return Dictionary.ContainsKey(key);
            }

            public ICollection<TKey> Keys
            {
                get { return Dictionary.Keys; }
            }

            public bool Remove(TKey key)
            {
                if (key == null) throw new ArgumentNullException("key");

                TValue value;
                Dictionary.TryGetValue(key, out value);

                int index = GetIndex(Dictionary, key);
                var removed = Dictionary.Remove(key);

                if (removed)
                    OnCollectionChanged(NotifyCollectionChangedAction.Remove, new KeyValuePair<TKey, TValue>(key, value), index);
                    //OnCollectionChanged();
                return removed;
            }

            public bool TryGetValue(TKey key, out TValue value)
            {
                return Dictionary.TryGetValue(key, out value);
            }

            public ICollection<TValue> Values
            {
                get { return Dictionary.Values; }
            }

            public TValue this[TKey key]
            {
                get
                {
                    return Dictionary[key];
                }
                set
                {
                    Insert(key, value, false);
                }
            }

            #endregion

            #region ICollection<KeyValuePair<TKey,TValue>> Members

            public void Add(KeyValuePair<TKey, TValue> item)
            {
                Insert(item.Key, item.Value, true);
            }

            public void Clear()
            {
                if (Dictionary.Count > 0)
                {
                    Dictionary.Clear();
                    OnCollectionChanged();
                }
            }

            public bool Contains(KeyValuePair<TKey, TValue> item)
            {
                return Dictionary.Contains(item);
            }

            public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
            {
                Dictionary.CopyTo(array, arrayIndex);
            }

            public int Count
            {
                get { return Dictionary.Count; }
            }

            public bool IsReadOnly
            {
                get { return Dictionary.IsReadOnly; }
            }

            public bool Remove(KeyValuePair<TKey, TValue> item)
            {
                return Remove(item.Key);
            }

            #endregion

            #region IEnumerable<KeyValuePair<TKey,TValue>> Members

            public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
            {
                return Dictionary.GetEnumerator();
            }

            #endregion

            #region IEnumerable Members

            IEnumerator IEnumerable.GetEnumerator()
            {
                return ((IEnumerable)Dictionary).GetEnumerator();
            }

            #endregion

            #region INotifyCollectionChanged Members

            public event NotifyCollectionChangedEventHandler CollectionChanged;

            #endregion

            #region INotifyPropertyChanged Members

            public event PropertyChangedEventHandler PropertyChanged;

            #endregion

            public void AddRange(IDictionary<TKey, TValue> items)
            {
                if (items == null) throw new ArgumentNullException("items");

                if (items.Count > 0)
                {
                    if (Dictionary.Count > 0)
                    {
                        if (items.Keys.Any((k) => Dictionary.ContainsKey(k)))
                            throw new ArgumentException("An item with the same key has already been added.");
                        else
                            foreach (var item in items) Dictionary.Add(item);
                    }
                    else
                        _Dictionary = new Dictionary<TKey, TValue>(items);

                    OnCollectionChanged(NotifyCollectionChangedAction.Add, items.ToArray(), GetIndex(Dictionary, items.Keys.First())); //We notify the index of the first added key
                }
            }

            private void Insert(TKey key, TValue value, bool add)
            {
                if (key == null) throw new ArgumentNullException("key");

                TValue item;
                if (Dictionary.TryGetValue(key, out item))
                {
                    if (add) throw new ArgumentException("An item with the same key has already been added.");
                    if (Equals(item, value)) return;
                    Dictionary[key] = value;

                    OnCollectionChanged(NotifyCollectionChangedAction.Replace, new KeyValuePair<TKey, TValue>(key, value), new KeyValuePair<TKey, TValue>(key, item), GetIndex(Dictionary, key));
                }
                else
                {
                    Dictionary[key] = value;

                    OnCollectionChanged(NotifyCollectionChangedAction.Add, new KeyValuePair<TKey, TValue>(key, value), GetIndex(Dictionary, key));
                }
            }

            private void OnPropertyChanged()
            {
                OnPropertyChanged(CountString);
                OnPropertyChanged(IndexerName);
                OnPropertyChanged(KeysName);
                OnPropertyChanged(ValuesName);
            }

            private int GetIndex(IDictionary<TKey, TValue> Dictionary, TKey key)
            {
                int i = 0;
                foreach (var dictKey in Dictionary.Keys)
                {
                    if (dictKey.Equals(key)) return i;
                }

                return -1;
            }

            protected virtual void OnPropertyChanged(string propertyName)
            {
                if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }

            private void OnCollectionChanged()
            {
                OnPropertyChanged();
                if (CollectionChanged != null) CollectionChanged(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
            }

            private void OnCollectionChanged(NotifyCollectionChangedAction action, KeyValuePair<TKey, TValue> changedItem, int index)
            {
                OnPropertyChanged();
                if (CollectionChanged != null) CollectionChanged(this, new NotifyCollectionChangedEventArgs(action, changedItem, index));
            }

            private void OnCollectionChanged(NotifyCollectionChangedAction action, KeyValuePair<TKey, TValue> newItem, KeyValuePair<TKey, TValue> oldItem, int index)
            {
                OnPropertyChanged();
                if (CollectionChanged != null) CollectionChanged(this, new NotifyCollectionChangedEventArgs(action, newItem, oldItem, index));
            }

            private void OnCollectionChanged(NotifyCollectionChangedAction action, IList newItems, int index)
            {
                OnPropertyChanged();
                if (CollectionChanged != null) CollectionChanged(this, new NotifyCollectionChangedEventArgs(action, newItems, index));
            }

            public override string ToString()
            {
                return string.Format("ObservableDictionary<{0}> Count={1}", GetKeyAndValue(Dictionary.GetType().GetGenericArguments()), Count);
            }

            private object GetKeyAndValue(Type[] Types)
            {
                string result = string.Empty;

                foreach (Type type in Types)
                {
                    result += type.ToString() + ",";
                }

                if (!string.IsNullOrEmpty(result) && result.Length > 1)
                    result = result.Substring(0, result.Length - 1);

                return result;
            }
        }
}

Pruébalo y dime cómo va.