如何为 flutter 设置 RETAIN 发布消息 Mqtt_client

Question

现在我可以使用这个发布消息了

MqttServerClient client = MqttServerClient.withPort(broker, "", 1883); //connect broker

//create message
final builder = MqttClientPayloadBuilder();
builder.addString(message);

client.publishMessage(topic, MqttQos.atLeastOnce, builder.payload); //publish message

但是如何将已发布的消息设置为保留。

Answer 1

根据 the docs 语法是：

int publishMessage(

    String topic,
    MqttQos qualityOfService,
    Uint8Buffer data,
    {bool retain = false}

)

所以你的 publish 需要是：

client.publishMessage(topic, MqttQos.atLeastOnce, builder.payload, true);

如何为 flutter 设置 RETAIN 发布消息 Mqtt_client

How to set RETAIN publish message for flutter Mqtt_client

flutter

dart

mqtt

android-mqtt-client