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MQTT5PublishMessage

The MQTT5PublishMessage class represents an MQTT 5 publish message. This class provides various properties and methods for defining the message details, such as the topic, payload, Quality of Service (QoS), and additional metadata.

Constructor​

MQTT5PublishMessage()​

Initializes a new instance of the MQTT5PublishMessage class.

MQTT5PublishMessage();

Example:

var message = new MQTT5PublishMessage();

MQTT5PublishMessage(string topic, QualityOfService? qos)​

Initializes a new instance of the MQTT5PublishMessage class with the specified topic and Quality of Service level.

MQTT5PublishMessage(string topic, QualityOfService? qos);

Parameters:

  • topic (string): The topic name.
  • qos (QualityOfService?): The QoS level.

Example:

var message = new MQTT5PublishMessage("home/sensors/temperature", QualityOfService.AtLeastOnce);

Properties​

Topic​

Gets or sets the topic of the publish message.

string? Topic { get; set; }

Description:
The topic where the message will be published.

Example:

message.Topic = "home/sensors/humidity";

QoS​

Gets or sets the Quality of Service level for the publish message.

QualityOfService? QoS { get; set; }

Description:
Specifies the QoS level for message delivery.

Example:

message.QoS = QualityOfService.ExactlyOnce;

PayloadFormatIndicator​

Gets or sets the payload format indicator.

MQTT5PayloadFormatIndicator? PayloadFormatIndicator { get; set; }

Description:
Indicates the format of the payload.

Example:

message.PayloadFormatIndicator = MQTT5PayloadFormatIndicator.Text;

MessageExpiryInterval​

Gets or sets the message expiry interval in seconds.

int? MessageExpiryInterval { get; set; }

Description:
The time after which the message expires.

Example:

message.MessageExpiryInterval = 3600;

TopicAlias​

Gets or sets the topic alias.

int? TopicAlias { get; set; }

Description:
An alias for the topic to reduce message size.

Example:

message.TopicAlias = 42;

ResponseTopic​

Gets or sets the response topic for the publish message.

string? ResponseTopic { get; set; }

Description:
Specifies the topic for response messages.

Example:

message.ResponseTopic = "home/responses/humidity";

CorrelationData​

Gets or sets the correlation data for the publish message.

byte[]? CorrelationData { get; set; }

Description:
Data used to correlate the message with a request.

Example:

message.CorrelationData = new byte[] { 0x01, 0x02 };

UserProperties​

Gets or sets the user properties of the publish message.

Dictionary<string, string> UserProperties { get; set; }

Description:
Custom key-value pairs to add metadata.

Example:

message.UserProperties["key1"] = "value1";

SubscriptionIdentifiers​

Gets or sets the subscription identifiers associated with the message.

List<int> SubscriptionIdentifiers { get; set; }

Description:
Identifies the subscriptions matching this message.

Example:

message.SubscriptionIdentifiers.Add(12345);

ContentType​

Gets or sets the content type of the payload.

string? ContentType { get; set; }

Description:
Indicates the type of the message payload.

Example:

message.ContentType = "application/json";

Payload​

Gets or sets the payload as a byte array.

byte[]? Payload { get; set; }

Description:
The message payload in binary format.

Example:

message.Payload = Encoding.UTF8.GetBytes("Hello, MQTT!");

PayloadAsString​

Gets or sets the payload as a string.

string PayloadAsString { get; set; }

Description:
The payload in string format.

Example:

message.PayloadAsString = "Hello, MQTT!";

Retain​

Gets or sets the retain flag of the message.

bool Retain { get; set; }

Description:
Indicates whether the message should be retained by the broker.

Example:

message.Retain = true;

Duplicate​

Gets or sets the duplicate flag of the message.

bool Duplicate { get; set; }

Description:
Indicates whether this message is a retransmission.

Example:

message.Duplicate = true;

Methods​

Validate()​

Validates the properties of the message.

void Validate();

Description:
Checks if the message properties are valid.

Example:

try
{
    message.Validate();
}
catch (HiveMQttClientException ex)
{
    Console.WriteLine($"Validation failed: {ex.Message}");
}