如何从esp32中查找PC本地ip以使用MQTT nodejs服务器

#include <WiFi.h>

const char* ssid = "YourWiFiSSID";
const char* password = "YourWiFiPassword";

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }

  Serial.println("Connected to WiFi");
}

void loop() {
  // Your code here
}

#include <WiFi.h>
#include <ESPmDNS.h>

const char* hostname = "esp32-device";

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }

  if (!MDNS.begin(hostname)) {
    Serial.println("Error setting up MDNS responder");
    while (1) {
      delay(1000);
    }
  }

  Serial.println("mDNS responder started");
}

void loop() {
  // Your code here
}

const mqtt = require('mqtt');
const server = mqtt.createServer();

server.on('clientConnected', (client) => {
  console.log('Client connected:', client.id);
});

server.on('published', (packet, client) => {
  console.log('Message received:', packet.payload.toString());
});

server.listen(1883, () => {
  console.log('MQTT server started');
});

const express = require('express');
const app = express();

app.get('/getLocalIP', (req, res) => {
  const localIP = req.connection.remoteAddress;
  res.send(localIP);
});

app.listen(3000, () => {
  console.log('HTTP server started');
});

#include <WiFi.h>
#include <WiFiClient.h>

const char* serverIP = "192.168.1.100"; // PC的IP地址
const int serverPort = 3000; // PC的HTTP接口端口

void setup() {
  Serial.begin(115200);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }

  Serial.println("Connected to WiFi");

  WiFiClient client;
  if (client.connect(serverIP, serverPort)) {
    client.println("GET /getLocalIP HTTP/1.1");
    client.println("Host: " + String(serverIP));
    client.println("Connection: close");
    client.println();

    while (client.connected()) {
      if (client.available()) {
        String response = client.readStringUntil('\r');
        Serial.println("Local IP: " + response);
        break;
      }
    }

    client.stop();
  }
}

void loop() {
  // Your code here
}