implement IDictionaryEnumerator to make sure that it can be serialize…

…d/deserialized properly

source/MongoDB/Document.cs

@@ -22,16 +22,16 @@ public class Document : IDictionary<string,object>, IDictionary, IXmlSerializabl
         /// <summary>
         /// Initializes a new instance of the <see cref="Document"/> class.
         /// </summary>
-        public Document(){
+        public Document(){
             _dictionary = new Dictionary<string, object>();
             _orderedKeys = new List<String>();
         }
-
-        /// <summary>
-        /// Initialize a new instance of the <see cref="Document"/> class with an optional key sorter.
+
+        /// <summary>
+        /// Initialize a new instance of the <see cref="Document"/> class with an optional key sorter.
         /// </summary>
-        public Document(IComparer<string> keyComparer)
-            :this()
+        public Document(IComparer<string> keyComparer)
+            :this()
         {
             if(keyComparer == null)
                 throw new ArgumentNullException("keyComparer");
@@ -431,17 +431,17 @@ void IDictionary.Remove(object key)
         /// Copies to items to destinationDocument.
         /// </summary>
         /// <param name="destinationDocument">The destination document.</param>
-        public void CopyTo(Document destinationDocument){
-            if(destinationDocument == null)
-                throw new ArgumentNullException("destinationDocument");
-
+        public void CopyTo(Document destinationDocument){
+            if(destinationDocument == null)
+                throw new ArgumentNullException("destinationDocument");
+
             //Todo: Fix any accidental reordering issues.
 
-            foreach(var key in _orderedKeys){
-                if(destinationDocument.ContainsKey(key))
-                    destinationDocument.Remove(key);
-                destinationDocument[key] = this[key];
-            }
+            foreach(var key in _orderedKeys){
+                if(destinationDocument.ContainsKey(key))
+                    destinationDocument.Remove(key);
+                destinationDocument[key] = this[key];
+            }
         }
         /// <summary>
         /// Removes the first occurrence of a specific object from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
@@ -614,25 +614,77 @@ bool IDictionary.IsFixedSize
             }
             return hash;
         }
-
-        /// <summary>
-        /// Returns an enumerator that iterates through a collection.
-        /// </summary>
-        /// <returns>
-        /// An <see cref="T:System.Collections.IEnumerator"/> object that can be used to iterate through the collection.
-        /// </returns>
-        IEnumerator IEnumerable.GetEnumerator(){
-            return GetEnumerator();
-        }
+
+        /// <summary>
+        /// Returns an enumerator that iterates through a collection.
+        /// </summary>
+        /// <returns>
+        /// An <see cref="T:System.Collections.IEnumerator"/> object that can be used to iterate through the collection.
+        /// </returns>
+        IEnumerator IEnumerable.GetEnumerator(){
+            return GetEnumerator();
+        }
 
         /// <summary>
         /// Returns an enumerator that iterates through the collection.
         /// </summary>
         /// <returns>
         /// A <see cref="T:System.Collections.Generic.IEnumerator`1"/> that can be used to iterate through the collection.
         /// </returns>
-        public IEnumerator<KeyValuePair<string, object>> GetEnumerator(){
-            return _orderedKeys.Select(orderedKey => new KeyValuePair<string, object>(orderedKey, _dictionary[orderedKey])).GetEnumerator();
+        public IEnumerator<KeyValuePair<string, object>> GetEnumerator()
+        {
+            return new Enumerator(this);
+        }
+
+        private class Enumerator : IEnumerator<KeyValuePair<string, object>>, IDictionaryEnumerator
+        {
+            private readonly Document _doc;
+            private readonly IEnumerator<string> _keysEnum;
+            public Enumerator(Document doc)
+            {
+                _doc = doc;
+                _keysEnum = doc._orderedKeys.GetEnumerator();
+            }
+
+            public void Dispose()
+            {
+                _keysEnum.Dispose();
+            }
+
+            public bool MoveNext()
+            {
+                return _keysEnum.MoveNext();
+            }
+
+            public void Reset()
+            {
+                _keysEnum.Reset();
+            }
+
+            public KeyValuePair<string, object> Current
+            {
+                get { return new KeyValuePair<string, object>(_keysEnum.Current, _doc[_keysEnum.Current]); }
+            }
+
+            object IEnumerator.Current
+            {
+                get { return Current; }
+            }
+
+            public object Key
+            {
+                get { return _keysEnum.Current; }
+            }
+
+            public object Value
+            {
+                get { return _doc[_keysEnum.Current]; }
+            }
+
+            public DictionaryEntry Entry
+            {
+                get { return new DictionaryEntry(_keysEnum.Current, _doc[_keysEnum.Current]); }
+            }
         }
 
         /// <summary>
@@ -723,4 +775,4 @@ void IXmlSerializable.WriteXml(XmlWriter writer)
             }
         }
     }
-}
+}