在C++中使用Kafka可以通過librdkafka庫實現。下面是一個簡單的示例代碼：

#include <librdkafka/rdkafkacpp.h>
#include <iostream>

int main() {
    std::string brokers = "localhost:9092";
    std::string topic = "test";

    RdKafka::Conf *conf = RdKafka::Conf::create(RdKafka::Conf::CONF_GLOBAL);
    conf->set("metadata.broker.list", brokers, errstr);

    RdKafka::Producer *producer = RdKafka::Producer::create(conf, errstr);
    if (!producer) {
        std::cerr << "Failed to create producer: " << errstr << std::endl;
        return 1;
    }

    RdKafka::Topic *rd_topic = RdKafka::Topic::create(producer, topic, tconf, errstr);

    RdKafka::ErrorCode resp = producer->produce(rd_topic, RdKafka::Topic::PARTITION_UA, RdKafka::Producer::RK_MSG_COPY,
                                                const_cast<char *>(message.c_str()), message.size(), NULL, NULL);

    if (resp != RdKafka::ERR_NO_ERROR) {
        std::cerr << "Failed to produce message: " << RdKafka::err2str(resp) << std::endl;
    }

    delete rd_topic;
    delete producer;

    return 0;
}

這段代碼創建了一個生產者，將消息發送到指定的Kafka主題中。你可以根據需要修改代碼來適配你的場景。同時，你可以通過librdkafka的文檔來了解更多的API和功能。