Nanopb正确编码和解码子消息中的重复构造字段

syntax = "proto2";

message SubMessage {
    required int32 id = 1;
    required string name = 2;
}

message MainMessage {
    repeated SubMessage sub_messages = 1;
}

#include "nanopb.h"
#include "main_message.pb.h"

void encode_message() {
    MainMessage msg = MainMessage_init_zero;
    SubMessage *sub_msg;

    // 添加第一个子消息
    sub_msg = MainMessage_sub_messages_add(&msg);
    sub_msg->id = 1;
    strcpy(sub_msg->name, "Message 1");

    // 添加第二个子消息
    sub_msg = MainMessage_sub_messages_add(&msg);
    sub_msg->id = 2;
    strcpy(sub_msg->name, "Message 2");

    uint8_t buffer[MainMessage_size];
    pb_ostream_t stream = pb_ostream_from_buffer(buffer, sizeof(buffer));

    if (!pb_encode(&stream, MainMessage_fields, &msg)) {
        printf("Encoding failed: %s\n", PB_GET_ERROR(&stream));
        return;
    }

    // buffer 现在包含编码后的数据
}

void decode_message(uint8_t *buffer, size_t size) {
    MainMessage msg = MainMessage_init_zero;
    pb_istream_t stream = pb_istream_from_buffer(buffer, size);

    if (!pb_decode(&stream, MainMessage_fields, &msg)) {
        printf("Decoding failed: %s\n", PB_GET_ERROR(&stream));
        return;
    }

    // 处理解码后的消息
    for (size_t i = 0; i < MainMessage_sub_messages_count(&msg); i++) {
        SubMessage sub_msg = MainMessage_sub_messages(&msg, i);
        printf("ID: %d, Name: %s\n", sub_msg.id, sub_msg.name);
    }
}