add some error handling for audio sessions

src/FocusVolumeControl/AudioHelpers/AudioHelper.cs

@@ -53,6 +53,11 @@ public class AudioHelper
 		{
 			deviceCollection.Item(d, out var device);
 
+			if(device == null)
+			{
+				continue;
+			}
+
 			Guid iid = typeof(IAudioSessionManager2).GUID;
 			device.Activate(ref iid, CLSCTX.ALL, IntPtr.Zero, out var m);
 			var manager = (IAudioSessionManager2)m;
@@ -61,6 +66,11 @@ public class AudioHelper
 
 			manager.GetSessionEnumerator(out var sessionEnumerator);
 
+			if(sessionEnumerator == null)
+			{
+				continue;
+			}
+
 			var currentIndex = int.MaxValue;
 
 			sessionEnumerator.GetCount(out var count);
@@ -68,6 +78,11 @@ public class AudioHelper
 			{
 				sessionEnumerator.GetSession(i, out var session);
 
+				if(session == null)
+				{
+					continue;
+				}
+
 				session.GetProcessId(out var sessionProcessId);
 				var audioProcess = GetProcessById(sessionProcessId);
 
@@ -241,6 +256,11 @@ public class AudioHelper
 		{
 			deviceCollection.Item(d, out var device);
 
+			if(device == null)
+			{
+				continue;
+			}
+
 			Guid iid = typeof(IAudioSessionManager2).GUID;
 			device.Activate(ref iid, CLSCTX.ALL, IntPtr.Zero, out var m);
 			var manager = (IAudioSessionManager2)m;
@@ -248,11 +268,21 @@ public class AudioHelper
 
 			manager.GetSessionEnumerator(out var sessionEnumerator);
 
+			if(sessionEnumerator == null)
+			{
+				continue;
+			}
+
 			sessionEnumerator.GetCount(out var count);
 			for (int i = 0; i < count; i++)
 			{
 				sessionEnumerator.GetSession(i, out var session);
 
+				if(session == null)
+				{
+					continue;
+				}
+
 				var volume = (ISimpleAudioVolume)session;
 				var guid = Guid.Empty;
 				volume.SetMasterVolume(1, ref guid);
@@ -271,6 +301,10 @@ public class AudioHelper
 		{
 			deviceCollection.Item(d, out var device);
 
+			if(device == null)
+			{
+				continue;
+			}
 
 			Guid iid = typeof(IAudioSessionManager2).GUID;
 			device.Activate(ref iid, CLSCTX.ALL, IntPtr.Zero, out var m);
@@ -279,11 +313,21 @@ public class AudioHelper
 
 			manager.GetSessionEnumerator(out var sessionEnumerator);
 
+			if(sessionEnumerator == null)
+			{
+				continue;
+			}
+
 			sessionEnumerator.GetCount(out var count);
 			for (int i = 0; i < count; i++)
 			{
 				sessionEnumerator.GetSession(i, out var session);
 
+				if(session == null)
+				{
+					continue;
+				}
+
 				if (session.IsSystemSoundsSession() == 0)
 				{
 					return new SystemSoundsAudioSession(session);
@@ -388,6 +432,11 @@ public class AudioHelper
 		{
 			deviceCollection.Item(d, out var device);
 
+			if(device == null)
+			{
+				continue;
+			}
+
 			Guid iid = typeof(IAudioSessionManager2).GUID;
 			device.Activate(ref iid, CLSCTX.ALL, IntPtr.Zero, out var m);
 			var manager = (IAudioSessionManager2)m;
@@ -396,10 +445,21 @@ public class AudioHelper
 
 			manager.GetSessionEnumerator(out var sessionEnumerator);
 
+			if(sessionEnumerator == null)
+			{
+				continue;
+			}
+
 			sessionEnumerator.GetCount(out var count);
 			for (int i = 0; i < count; i++)
 			{
 				sessionEnumerator.GetSession(i, out var session);
+
+				if(session == null)
+				{
+					continue;
+				}
+
 				session.GetDisplayName(out var displayName);
 				session.GetProcessId(out var sessionProcessId);
 

src/FocusVolumeControl/manifest.json

@@ -33,7 +33,7 @@
   "Name": "Focused Application Volume",
   "Description": "Control the volume of the focused application",
   "URL": "https://github.com/dlprows/FocusVolumeControl",
-  "Version": "1.3.0",
+  "Version": "1.3.1",
   "CodePath": "FocusVolumeControl",
   "Category": "Volume Control [dlprows]",
   "Icon": "Images/pluginIcon",