如何使用Paho MQTT C客户端发送整数和字符数组

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "MQTTClient.h"

#define ADDRESS     "tcp://mqtt.example.com:1883"
#define CLIENTID    "ExampleClient"
#define TOPIC       "example/topic"
#define QOS         1
#define TIMEOUT     10000L

int main(int argc, char* argv[])
{
    MQTTClient client;
    MQTTClient_connectOptions conn_opts = MQTTClient_connectOptions_initializer;
    int rc;

    MQTTClient_create(&client, ADDRESS, CLIENTID, MQTTCLIENT_PERSISTENCE_NONE, NULL);
    conn_opts.keepAliveInterval = 20;
    conn_opts.cleansession = 1;

    if ((rc = MQTTClient_connect(client, &conn_opts)) != MQTTCLIENT_SUCCESS) {
        printf("Failed to connect to MQTT server, return code %d\n", rc);
        exit(EXIT_FAILURE);
    }

    // 发布整数数据
    int integerData = 123;
    MQTTClient_message pubmsg = MQTTClient_message_initializer;
    pubmsg.payload = &integerData;
    pubmsg.payloadlen = sizeof(int);
    pubmsg.qos = QOS;
    pubmsg.retained = 0;
    MQTTClient_publishMessage(client, TOPIC, &pubmsg, NULL);

    // 发布字符数组
    char charArrayData[] = "Hello, MQTT!";
    MQTTClient_message pubmsg2 = MQTTClient_message_initializer;
    pubmsg2.payload = charArrayData;
    pubmsg2.payloadlen = strlen(charArrayData);
    pubmsg2.qos = QOS;
    pubmsg2.retained = 0;
    MQTTClient_publishMessage(client, TOPIC, &pubmsg2, NULL);

    MQTTClient_disconnect(client, 10000);
    MQTTClient_destroy(&client);

    return EXIT_SUCCESS;
}