fixed message enqueue exception in v2.2

build/version.props

@@ -2,7 +2,7 @@
 	<PropertyGroup>
 		<VersionMajor>2</VersionMajor>
 		<VersionMinor>2</VersionMinor>
-		<VersionPatch>0</VersionPatch>
+		<VersionPatch>1</VersionPatch>
 		<VersionQuality></VersionQuality>
 		<VersionPrefix>$(VersionMajor).$(VersionMinor).$(VersionPatch)</VersionPrefix>
 	</PropertyGroup>

src/DotNetCore.CAP/Diagnostics/DiagnosticListenerExtensions.cs

@@ -107,6 +107,7 @@ namespace DotNetCore.CAP.Diagnostics
         {
             if (@this.IsEnabled(CapBeforePublish))
             {
+                eventData.Headers = new TracingHeaders();
                 @this.Write(CapBeforePublish, eventData);
             }
         }
@@ -115,6 +116,7 @@ namespace DotNetCore.CAP.Diagnostics
         {
             if (@this.IsEnabled(CapAfterPublish))
             {
+                eventData.Headers = new TracingHeaders();
                 @this.Write(CapAfterPublish, eventData);
             }
         }
@@ -123,6 +125,7 @@ namespace DotNetCore.CAP.Diagnostics
         {
             if (@this.IsEnabled(CapErrorPublish))
             {
+                eventData.Headers = new TracingHeaders();
                 @this.Write(CapErrorPublish, eventData);
             }
         }
@@ -135,6 +138,7 @@ namespace DotNetCore.CAP.Diagnostics
         {
             if (@this.IsEnabled(CapBeforeConsume))
             {
+                eventData.Headers = new TracingHeaders();
                 @this.Write(CapBeforeConsume, eventData);
             }
 
@@ -145,6 +149,7 @@ namespace DotNetCore.CAP.Diagnostics
         {
             if (@this.IsEnabled(CapAfterConsume))
             {
+                eventData.Headers = new TracingHeaders();
                 @this.Write(CapAfterConsume, eventData);
             }
         }
@@ -153,6 +158,7 @@ namespace DotNetCore.CAP.Diagnostics
         {
             if (@this.IsEnabled(CapErrorConsume))
             {
+                eventData.Headers = new TracingHeaders();
                 @this.Write(CapErrorConsume, eventData);
             }
         }

src/DotNetCore.CAP/Diagnostics/EventData.Broker.cs

@@ -11,7 +11,6 @@ namespace DotNetCore.CAP.Diagnostics
             string brokerTopicName, string brokerTopicBody)
             : base(operationId, operation)
         {
-            Headers = new TracingHeaders();
             BrokerAddress = brokerAddress;
             BrokerTopicName = brokerTopicName;
             BrokerTopicBody = brokerTopicBody;

src/DotNetCore.CAP/IPublishMessageSender.Base.cs

@@ -147,7 +147,7 @@ namespace DotNetCore.CAP
 
             s_diagnosticListener.WritePublishBefore(eventData);
 
-            return (operationId, eventData.Headers);
+            return (operationId, eventData.Headers);  //if not enabled diagnostics ,the header will be null
         }
 
         private void TracingAfter(Guid operationId, string topic, string values, DateTimeOffset startTime, TimeSpan du)