MessageOut Event

Fired when an outgoing message has been sent and/or fully acknowledged.

Syntax

ANSI (Cross Platform)
virtual int FireMessageOut(MQTTMessageOutEventParams *e);

typedef struct {
  int PacketId;
  const char *Topic;
  int QOS;
  const char *Message;
  int lenMessage;
  int Retained;
  int Duplicate;
  int reserved;
} MQTTMessageOutEventParams;

Unicode (Windows)
virtual INT FireMessageOut(MQTTMessageOutEventParams *e);

typedef struct {
  INT PacketId;
  LPCWSTR Topic;
  INT QOS;
  LPCSTR Message;
  INT lenMessage;
  BOOL Retained;
  BOOL Duplicate;
  INT reserved;
} MQTTMessageOutEventParams;
- (void)onMessageOut:(int)packetId :(NSString*)topic :(int)QOS :(NSData*)message :(BOOL)retained :(BOOL)duplicate;
#define EID_MQTT_MESSAGEOUT 8

virtual INT IPWORKSMQ_CALL FireMessageOut(INT &iPacketId, LPSTR &lpszTopic, INT &iQOS, LPSTR &lpMessage, INT &lenMessage, BOOL &bRetained, BOOL &bDuplicate);

Remarks

The MessageOut event fires once for each outgoing message either immediately after it is sent (QoS 0), or after it has been fully acknowledged by the receiver (QoS 1 and 2).

  • PacketId: The message packet Id. This will always be -1 if QOS is 0.
  • Topic: The message's topic string.
  • QOS: The message's QoS level.
  • Message: The message data.
  • Retained: Whether or not this message was sent with the "Retain" flag set.
  • Duplicate: Whether or not this message was sent with the "Duplicate" flag set.

Refer to MessageAck for more information about QoS 1 and 2 message processing steps.


view source
// MessageOut event handler.
mqtt1.OnMessageOut += (s, e) => {
  Console.WriteLine("Send message to topic '" + e.Topic + "' with QoS " + e.QOS + ":");
  Console.WriteLine(e.Message);
};
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IPWorks MQ 2020 C++ Edition - Version 20.0 [Build 8155]