Trouble with a script...

[Johana.Klotz]

Hello all,

i’m trying to make the same project as this vídeo: http://www.youtube.com/watch?v=o_wQ8Kw6A_s

but i’ have the error:

“NullReferenceException: Object reference not set to an instance of an object
MenuManager.Menu_Main () (at Assets/Scripts/MenuManager.cs:40)
MenuManager.OnGUI () (at Assets/Scripts/MenuManager.cs:20)”

My files:
MultiplayerManager.cs

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class MultiplayerManager : MonoBehaviour
{

public static MultiplayerManager instance;

public string PlayerName;

private string MatchName = “”;
private string MatchPassword = “”;
private int MatchMaxUsers = 32;

public List PlayerList = new List();

void start()
{
instance = this;
}

public void StartServer(string servername, string serverpassword, int maxusers)
{
MatchName = servername;
MatchPassword = serverpassword;
MatchMaxUsers = maxusers;
Network.InitializeServer(MatchMaxUsers, 2550, false);
Network.InitializeSecurity();
}

void OnServerinitialized()
{
Server_PlayerJoinRequest(“”, Network.player);
}

void OnConnectedToServer()
{
networkView.RPC (“Server_PlayerJoinRequest”, RPCMode.Server, “”, Network.player);
}

void OnPlayerDisconnected(NetworkPlayer id)
{
networkView.RPC (“Client_RemovePlayer”, RPCMode.All, id);

}

[RPC]
void Server_PlayerJoinRequest(string playername, NetworkPlayer view)
{
networkView.RPC (“Client_AddPlayerToList”, RPCMode.All, playername, view);

}

[RPC]
void Client_AddPlayerToList(string playername, NetworkPlayer view)
{
MPPlayer tempplayer = new MPPlayer();
tempplayer.PlayerName = playername;
tempplayer.PlayerNetwork = view;
PlayerList.Add (tempplayer);
}
[RPC]
void Client_RemovePlayer(NetworkPlayer view)
{
MPPlayer temppl = null;
foreach(MPPlayer pl in PlayerList)
{
if (pl.PlayerNetwork == view)
{
temppl = pl;
}
}
if (temppl != null)
{
PlayerList.Remove(temppl);
}

}

}

public class MPPlayer
{
public string PlayerName = “”;
public NetworkPlayer PlayerNetwork;
}

and MenuManager.cs:

using UnityEngine;
using System.Collections;

public class MenuManager : MonoBehaviour
{
public string CurrentMenu;

public string MatchName = “”;
public string MatchPassword = “”;
public int MatchMaxPlayers = 32;

void Start()
{
CurrentMenu = “Main”;
}

void OnGUI()
{
if (CurrentMenu == “Main”)
Menu_Main();
if (CurrentMenu == “Lobby”)
Menu_Lobby();
if (CurrentMenu == “Host”)
Menu_HostMenu();
}

public void NavigateTo(string nextmenu)
{
CurrentMenu = nextmenu;
}

private void Menu_Main()
{
if (GUI.Button(new Rect(10,10,200,50), “Host Game”))
{
NavigateTo(“Host”);
}

GUI.Label(new Rect(220, 20, 150, 50), “Player Name”);
MultiplayerManager.instance.PlayerName = GUI.TextField(new Rect(400, 10, 200, 30), MultiplayerManager.instance.PlayerName);
}

private void Menu_Lobby()
{
}

private void Menu_HostMenu() //Host Game Menu
{
if (GUI.Button(new Rect(10,10,200,50), “Back”))
{
NavigateTo(“Main”);
}

if (GUI.Button(new Rect(10,60,200,50), “Start Server”))
{
MultiplayerManager.instance.StartServer(MatchName, MatchPassword, MatchMaxPlayers);
}
GUI.Label(new Rect(220, 10, 130, 30),“Match Name”);
MatchName = GUI.TextField(new Rect(400, 10, 200, 30), MatchName);

GUI.Label(new Rect(220, 50, 130, 30),“Match Password”);
MatchPassword = GUI.PasswordField(new Rect(400, 50, 200, 30), MatchPassword, ‘*’);

GUI.Label(new Rect(220, 90, 130, 30),“Match Max Players”);
GUI.Label(new Rect(400, 90, 130, 30), MatchMaxPlayers.ToString());
MatchMaxPlayers = Mathf.Clamp(MatchMaxPlayers, 8, 32);

if (GUI.Button(new Rect(425,90,25,30), “+”))
MatchMaxPlayers +=2;
if (GUI.Button(new Rect(450,90,25,30), “-”))
MatchMaxPlayers -=2;

}
}

[BFGames]

Its the way you use the static instance thing.

MultiplayerManager.instance.PlayerName

This might help you understand why: http://msdn.microsoft.com/en-us/library/aa645629(v=vs.71).aspx

You cannot reach the PlayerName in that manner.
In your case i think a singleton pattern for your multiplayer instance would solve what you are trying to do.

[DexRobinson]

Change your start function to awake in your MultiplayerManager.cs

[Johana.Klotz]

thanks for the help… i’m totally newbie here, and just want to do this menu for a experimental game…
DexRobinson, i’ve tryed to substitute “Start” for “Awake”, but no results…
BFGames, i don’t know how to put it on a single pattern, and have no idea on the difference between static and instance members… could you just put the line in the correct way for me? thanks!

[Johana.Klotz]

I can’t understand… i’ve made everyting equal to the video (http://www.youtube.com/watch?v=o_wQ8Kw6A_s) and it works in the video but doesn’t work for me… =(

[KelsoMRK]

In MultiplayerManager void start() should be void Start() (upper case S)

[Johana.Klotz]

Thank you very much KelsoMRK! Solved the question!