gpd-924-en/Networking/Assets/Scripts/Menu.cs

using System;
using Unity.Netcode;
using UnityEngine;
using UnityEngine.SceneManagement;

namespace DefaultNamespace
{
    public class Menu : MonoBehaviour
    {
        [SerializeField] private GameObject lobbyUi;

        private void Start()
        {
            NetworkManager.Singleton.OnServerStarted += OnNetworkInstanceStarted;
            NetworkManager.Singleton.OnClientStarted += OnNetworkInstanceStarted;

            NetworkManager.Singleton.OnServerStopped += OnNetworkInstanceStopped;
            NetworkManager.Singleton.OnClientStopped += OnNetworkInstanceStopped;
        }

        private void OnDestroy()
        {
            NetworkManager.Singleton.OnServerStarted -= OnNetworkInstanceStarted;
            NetworkManager.Singleton.OnClientStarted -= OnNetworkInstanceStarted;

            NetworkManager.Singleton.OnServerStopped -= OnNetworkInstanceStopped;
            NetworkManager.Singleton.OnClientStopped -= OnNetworkInstanceStopped;
        }

        private void OnNetworkInstanceStopped(bool obj)
        {
            lobbyUi.SetActive(true);
        }

        private void OnNetworkInstanceStarted()
        {
            lobbyUi.SetActive(false);
        }
    }
}