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PublishMessageBuilder

The PublishMessageBuilder class is a builder for constructing MQTT 5 publish messages in the HiveMQ client. This class provides a fluent API for setting various properties of the publish message.

Constructor​

PublishMessageBuilder()

Initializes a new instance of the PublishMessageBuilder class.

Methods​

WithPayload(byte[] payload)​

Sets the payload of the publish message as a byte array.

PublishMessageBuilder WithPayload(byte[] payload);

Description:
Sets the payload to be published as a byte array.

Example:

var builder = new PublishMessageBuilder()
    .WithPayload(new byte[] { 0x01, 0x02, 0x03 });

WithPayload(string payload)​

Sets the payload of the publish message as a UTF-8 encoded string.

PublishMessageBuilder WithPayload(string payload);

Description:
Sets the payload to be published as a string.

Example:

var builder = new PublishMessageBuilder()
    .WithPayload("Hello, MQTT!");

WithTopic(string topic)​

Sets the topic of the publish message.

PublishMessageBuilder WithTopic(string topic);

Description:
Specifies the topic where the message will be published. Topics must be valid MQTT topic strings.

Example:

var builder = new PublishMessageBuilder()
    .WithTopic("home/sensors/temperature");

Exceptions:

  • ArgumentException: If the topic is null, empty, or invalid.

WithQualityOfService(QualityOfService qos)​

Sets the Quality of Service (QoS) level of the publish message.

PublishMessageBuilder WithQualityOfService(QualityOfService qos);

Description:
Sets the reliability level for message delivery.

Example:

var builder = new PublishMessageBuilder()
    .WithQualityOfService(QualityOfService.AtLeastOnce);

WithRetain(bool retain)​

Sets the retain flag of the publish message.

PublishMessageBuilder WithRetain(bool retain);

Description:
Determines whether the broker should retain the message for new subscribers.

Example:

var builder = new PublishMessageBuilder()
    .WithRetain(true);

WithDuplicate(bool duplicate)​

Sets the duplicate flag of the publish message.

PublishMessageBuilder WithDuplicate(bool duplicate);

Description:
Indicates whether the message is a duplicate of a previous message.

Example:

var builder = new PublishMessageBuilder()
    .WithDuplicate(true);

WithResponseTopic(string responseTopic)​

Sets the response topic for the publish message.

PublishMessageBuilder WithResponseTopic(string responseTopic);

Description:
Defines the response topic for the message.

Example:

var builder = new PublishMessageBuilder()
    .WithResponseTopic("responses/temperature");

WithCorrelationData(byte[] correlationData)​

Sets the correlation data for the publish message as a byte array.

PublishMessageBuilder WithCorrelationData(byte[] correlationData);

Description:
Adds correlation data to the message.

Example:

var builder = new PublishMessageBuilder()
    .WithCorrelationData(new byte[] { 0x01, 0x02 });

WithCorrelationData(string correlationData)​

Sets the correlation data for the publish message as a UTF-8 encoded string.

PublishMessageBuilder WithCorrelationData(string correlationData);

Description:
Adds correlation data as a string.

Example:

var builder = new PublishMessageBuilder()
    .WithCorrelationData("session-1234");

WithContentType(string contentType)​

Sets the content type of the publish message.

PublishMessageBuilder WithContentType(string contentType);

Description:
Specifies the content type of the payload.

Example:

var builder = new PublishMessageBuilder()
    .WithContentType("application/json");

WithMessageExpiryInterval(int messageExpiryInterval)​

Sets the message expiry interval of the publish message.

PublishMessageBuilder WithMessageExpiryInterval(int messageExpiryInterval);

Description:
Sets the expiry time for the message in seconds.

Example:

var builder = new PublishMessageBuilder()
    .WithMessageExpiryInterval(3600);

WithSubscriptionIdentifier(int subscriptionIdentifier)​

Adds a subscription identifier to the publish message.

PublishMessageBuilder WithSubscriptionIdentifier(int subscriptionIdentifier);

Description:
Associates the message with a specific subscription.

Example:

var builder = new PublishMessageBuilder()
    .WithSubscriptionIdentifier(1);

WithSubscriptionIdentifiers(List subscriptionIdentifiers)​

Adds multiple subscription identifiers to the publish message.

PublishMessageBuilder WithSubscriptionIdentifiers(List<int> subscriptionIdentifiers);

Description:
Associates the message with multiple subscriptions.

Example:

var builder = new PublishMessageBuilder()
    .WithSubscriptionIdentifiers(new List<int> { 1, 2, 3 });

WithTopicAlias(int topicAlias)​

Sets the topic alias of the publish message.

PublishMessageBuilder WithTopicAlias(int topicAlias);

Description:
Assigns a topic alias for efficient transmission.

Example:

var builder = new PublishMessageBuilder()
    .WithTopicAlias(42);

WithUserProperty(string key, string value)​

Adds a user property to the publish message.

PublishMessageBuilder WithUserProperty(string key, string value);

Description:
Adds a custom key-value pair to the message.

Example:

var builder = new PublishMessageBuilder()
    .WithUserProperty("key", "value");

WithUserProperties(Dictionary<string, string> properties)​

Adds multiple user properties to the publish message.

PublishMessageBuilder WithUserProperties(Dictionary<string, string> properties);

Description:
Adds multiple custom key-value pairs.

Example:

var builder = new PublishMessageBuilder()
    .WithUserProperties(new Dictionary<string, string>
    {
        { "key1", "value1" },
        { "key2", "value2" }
    });

WithPayloadFormatIndicator(MQTT5PayloadFormatIndicator indicator)​

Sets the payload format indicator of the publish message.

PublishMessageBuilder WithPayloadFormatIndicator(MQTT5PayloadFormatIndicator indicator);

Description:
Specifies the format of the payload.

Example:

var builder = new PublishMessageBuilder()
    .WithPayloadFormatIndicator(MQTT5PayloadFormatIndicator.Text);

Build​

Builds the publish message.

MQTT5PublishMessage Build();

Description:
Creates the final MQTT5PublishMessage instance.

Example:

var message = new PublishMessageBuilder()
    .WithTopic("home/sensors/temperature")
    .WithPayload("22.5°C")
    .Build();