MediaList: Implement IEnumerable/IEnumerator

LibVLCSharp.Tests/MediaDiscovererTests.cs

 using System;
+using System.Diagnostics;
 using System.Linq;
+using System.Threading.Tasks;
 using LibVLCSharp.Shared;
 using NUnit.Framework;
 
@@ -20,13 +22,18 @@ namespace LibVLCSharp.Tests
         }
 
         [Test]
-        public void DisposeMediaDiscoverer()
+        public async Task DisposeMediaDiscoverer()
         {
             var mds = _libVLC.MediaDiscoverers(MediaDiscovererCategory.Lan);
             var md = new MediaDiscoverer(_libVLC, mds.First().Name);
             Assert.True(md.Start());
             Assert.True(md.IsRunning);
             Assert.NotNull(md.MediaList);
+            await Task.Delay(1000);
+            foreach(var media in md.MediaList)
+            {
+                Debug.WriteLine(media.Mrl);
+            }
             md.Dispose();
             Assert.IsNull(md.MediaList);
             Assert.False(md.IsRunning);

LibVLCSharp.Tests/MediaListTests.cs

@@ -17,7 +17,6 @@ namespace LibVLCSharp.Tests
             var itemDeleted = false;
             mediaList.ItemAdded += (sender, args) => itemAdded = true;
             mediaList.ItemDeleted += (sender, args) => itemDeleted = true;
-            mediaList.Lock();
             mediaList.AddMedia(media);
             Assert.AreEqual(media, mediaList[0]);
             Assert.AreEqual(1, mediaList.Count);
@@ -26,24 +25,6 @@ namespace LibVLCSharp.Tests
             mediaList.RemoveIndex(0);
             Assert.Zero(mediaList.Count);
             Assert.True(itemDeleted);
-            mediaList.Unlock();
-        }
-
-        [Test]
-        public void AcquireLockTwiceThrows()
-        {
-            var mediaList = new MediaList(_libVLC);
-            mediaList.Lock();
-            Assert.Throws<InvalidOperationException>(() => mediaList.Lock(), "already locked");
-        }
-
-        [Test]
-        public void ReleaseLockTwiceThrows()
-        {
-            var mediaList = new MediaList(_libVLC);
-            mediaList.Lock();
-            mediaList.Unlock();
-            Assert.Throws<InvalidOperationException>(() => mediaList.Unlock(), "not locked");
         }
 
         [Test]

LibVLCSharp/Shared/MediaList.cs

 using System;
+using System.Collections;
+using System.Collections.Generic;
 using System.Runtime.InteropServices;
 
 namespace LibVLCSharp.Shared
 {
-    public class MediaList : Internal
+    public class MediaList : Internal, IEnumerable
     {
         MediaListEventManager _eventManager;
         readonly object _syncLock = new object();
@@ -145,9 +147,13 @@ namespace LibVLCSharp.Shared
             }
             finally
             {
+                lock (_syncLock)
+                {
+                    if (_nativeLock)
                         Unlock();
                 }       
             }
+        }
 
         /// <summary>
         /// Insert media instance in media list on a position.
@@ -286,5 +292,40 @@ namespace LibVLCSharp.Shared
 
             base.Dispose(disposing);
         }
+
+        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+
+        public MediaListEnumerator GetEnumerator() => new MediaListEnumerator(this);
+
+        public class MediaListEnumerator : IEnumerator<Media>
+        {
+            int position = -1;
+            MediaList _mediaList;
+
+            internal MediaListEnumerator(MediaList mediaList)
+            {
+                _mediaList = mediaList;
+            }
+
+            public bool MoveNext()
+            {
+                position++;
+                return position < _mediaList.Count;
+            }
+
+            void IEnumerator.Reset()
+            {
+                position = -1;
+            }
+
+            public void Dispose()
+            {
+                position = -1;
+                _mediaList = default;
+            }
+
+            object IEnumerator.Current => Current;
+            public Media Current => _mediaList[position];
+        }
     }
 }
\ No newline at end of file