Event Reference
This document provides a comprehensive list of events supported by the HiveMQtt client library. These events are categorized into two sections: General and Packet Level.
General Events
General events are triggered by high-level operations such as connecting, subscribing, unsubscribing, and receiving messages.
| Event | EventArgs Class | Event Arguments |
|---|---|---|
| BeforeConnect | BeforeConnectEventArgs | HiveMQClientOptions |
| AfterConnect | AfterConnectEventArgs | ConnectResult |
| BeforeSubscribe | BeforeSubscribeEventArgs | SubscribeOptions |
| AfterSubscribe | AfterSubscribeEventArgs | SubscribeResult |
| BeforeUnsubscribe | BeforeUnsubscribeEventArgs | UnsubscribeOptions |
| AfterUnsubscribe | AfterUnsubscribeEventArgs | UnsubscribeResult |
| OnMessageReceived | OnMessageReceivedEventArgs | MQTT5PublishMessage |
| BeforeDisconnect | BeforeDisconnectEventArgs | None |
| AfterDisconnect | AfterDisconnectEventArgs | CleanDisconnect |
Packet Level Events
Packet level events are triggered by the underlying MQTT packet activity. These events provide a more granular level of control and can be useful for debugging or advanced use cases.
| Event | EventArgs Class | Event Arguments |
|---|---|---|
| OnConnectSent | OnConnectSentEventArgs | ConnectPacket |
| OnConnAckReceived | OnConnAckReceivedEventArgs | ConnAckPacket |
| OnDisconnectSent | OnDisconnectSentEventArgs | DisconnectPacket |
| OnDisconnectReceived | OnDisconnectReceivedEventArgs | DisconnectPacket |
| OnPingReqSent | OnPingReqSentEventArgs | PingReqPacket |
| OnPingRespReceived | OnPingRespReceivedEventArgs | PingRespPacket |
| OnPublishSent | OnPublishSentEventArgs | PublishPacket |
| OnPublishReceived | OnPublishReceivedEventArgs | PublishPacket |
| OnPubAckSent | OnPubAckSentEventArgs | PubAckPacket |
| OnPubAckReceived | OnPubAckReceivedEventArgs | PubAckPacket |
| OnPubRecSent | OnPubRecSentEventArgs | PubRecPacket |
| OnPubRecReceived | OnPubRecReceivedEventArgs | PubRecPacket |
| OnPubRelSent | OnPubRelSentEventArgs | PubRelPacket |
| OnPubRelReceived | OnPubRelReceivedEventArgs | PubRelPacket |
| OnPubCompSent | OnPubCompSentEventArgs | PubCompPacket |
| OnPubCompReceived | OnPubCompReceivedEventArgs | PubCompPacket |
| OnSubscribeSent | OnSubscribeSentEventArgs | SubscribePacket |
| OnSubAckReceived | OnSubAckReceivedEventArgs | SubAckPacket |
| OnUnsubscribeSent | OnUnsubscribeSentEventArgs | UnsubscribePacket |
| OnUnsubAckReceived | OnUnsubAckReceivedEventArgs | UnsubAckPacket |
For OnPubAckReceived and OnPubRecReceived, the event arguments expose a packet with a ReasonString property. When the broker sends a human-readable reason (e.g. for schema validation or other diagnostics), args.PubAckPacket.ReasonString or args.PubRecPacket.ReasonString will be set; otherwise it is null.