Initial commit.

MQTT.NET.Core/Adapter/MqttConnectingFailedException.cs

@@ -0,0 +1,16 @@
+using MQTTnet.Core.Exceptions;
+using MQTTnet.Core.Protocol;
+
+namespace MQTTnet.Core.Adapter
+{
+    public class MqttConnectingFailedException : MqttCommunicationException
+    {
+        public MqttConnectingFailedException(MqttConnectReturnCode returnCode) 
+            : base($"Connecting with MQTT server failed ({returnCode}).")
+        {
+            ReturnCode = returnCode;
+        }
+
+        public MqttConnectReturnCode ReturnCode { get; }
+    }
+}