Use RX in streaming sample

samples/SocketsSample/Hubs/Streaming.cs

@@ -1,6 +1,5 @@
 using System;
-using System.IO;
+using System.Reactive.Linq;
-using System.Threading;
 using System.Threading.Tasks;
 using System.Threading.Tasks.Channels;
 using Microsoft.AspNetCore.SignalR;
@@ -11,7 +10,9 @@ namespace SocketsSample.Hubs
     {
         public IObservable<int> ObservableCounter(int count, int delay)
         {
-            return new CounterObservable(count, delay);
+            return Observable.Interval(TimeSpan.FromMilliseconds(delay))
+                             .Select((_, index) => index)
+                             .Take(count);
         }
 
         public ReadableChannel<int> ChannelCounter(int count, int delay)
@@ -31,49 +32,5 @@ namespace SocketsSample.Hubs
 
             return channel.In;
         }
-
-        private class CounterObservable : IObservable<int>
-        {
-            private int _count;
-            private int _delay;
-
-            public CounterObservable(int count, int delay)
-            {
-                _count = count;
-                _delay = delay;
-            }
-
-            public IDisposable Subscribe(IObserver<int> observer)
-            {
-                // Run in a thread-pool thread
-                var cts = new CancellationTokenSource();
-                Task.Run(async () =>
-                {
-                    for (var i = 0; !cts.Token.IsCancellationRequested && i < _count; i++)
-                    {
-                        observer.OnNext(i);
-                        await Task.Delay(_delay);
-                    }
-                    observer.OnCompleted();
-                });
-
-                return new Disposable(() => cts.Cancel());
-            }
-        }
-
-        private class Disposable : IDisposable
-        {
-            private Action _action;
-
-            public Disposable(Action action)
-            {
-                _action = action;
-            }
-
-            public void Dispose()
-            {
-                _action();
-            }
-        }
     }
 }

samples/SocketsSample/SocketsSample.csproj

@@ -29,6 +29,7 @@
     <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="$(AspNetCoreVersion)" />
     <PackageReference Include="Microsoft.Extensions.Configuration.CommandLine" Version="$(AspNetCoreVersion)" />
     <PackageReference Include="Google.Protobuf" Version="$(GoogleProtobufVersion)" />
+    <PackageReference Include="System.Reactive.Linq" Version="$(RxVersion)" />
   </ItemGroup>
 
   <Target Name="CopyTSClient" BeforeTargets="AfterBuild">