upgrade Confluent.Kafka version.

src/DotNetCore.CAP.Kafka/DotNetCore.CAP.Kafka.csproj

@@ -14,7 +14,7 @@
   </PropertyGroup>
  
   <ItemGroup>
-    <PackageReference Include="Confluent.Kafka" Version="0.9.5" />
+    <PackageReference Include="Confluent.Kafka" Version="0.11.0" />
   </ItemGroup>
 
   <ItemGroup>

src/DotNetCore.CAP.Kafka/PublishQueueExecutor.cs

@@ -28,26 +28,32 @@ namespace DotNetCore.CAP.Kafka
             try
             {
                 var config = _kafkaOptions.AsRdkafkaConfig();
-                using (var producer = new Producer<Null, string>(config, null, new StringSerializer(Encoding.UTF8)))
+                var contentBytes = Encoding.UTF8.GetBytes(content);
+                using (var producer = new Producer(config))
                 {
-                    producer.ProduceAsync(keyName, null, content);
-                    producer.Flush();
-                }
+                    var message = producer.ProduceAsync(keyName, null, contentBytes).Result;
 
+                    if (!message.Error.HasError)
+                    {
                         _logger.LogDebug($"kafka topic message [{keyName}] has been published.");
 
                         return Task.FromResult(OperateResult.Success);
                     }
+                    else
+                    {
+                        return Task.FromResult(OperateResult.Failed(new OperateError
+                        {
+                            Code = message.Error.Code.ToString(),
+                            Description = message.Error.Reason
+                        }));
+                    }
+                }
+            }
             catch (Exception ex)
             {
                 _logger.LogError($"kafka topic message [{keyName}] has benn raised an exception of sending. the exception is: {ex.Message}");
 
-                return Task.FromResult(OperateResult.Failed(ex,
-                    new OperateError()
-                    {
-                        Code = ex.HResult.ToString(),
-                        Description = ex.Message
-                    }));
+                return Task.FromResult(OperateResult.Failed(ex));
             }
         }
     }