c# - Unity how to find a server from client using NetworkDiscovery

Question

[I work in c#]

In order to decide weather a device should become a server with local client or client alone (for main-server-less networking) I need to find out if there are any other available servers for that device before turning into a server with local client if not for another client device to join by either receiving NetworkDiscovery broadcasts from a server or not - currently I can't get a client to receive broadcast from a server.

I have created two empty gameobjects each with scripts, one script makes it a server and should be broadcasting from its NetworkDiscovery via NetworkDiscovery.StartAsServer() but currently one my client whose NetworkDiscovery has been set to NetworkDiscovery.StartAsClient() is not getting theOnRecievedBroadcast() function called hence not receiving broadcasts from the server.

The two scripts shown below are the client and server:

Client -

using UnityEngine;
using System.Collections;
using UnityEngine.Networking;

public class SearchForServers : MonoBehaviour {
    bool serverIsFound;
    NetworkDiscovery NetworkDiscovery;
    // Use this for initialization
    void Start () {
        serverIsFound = false;
        NetworkClient Client = new NetworkClient();
        NetworkDiscovery = gameObject.AddComponent<NetworkDiscovery>();
        NetworkDiscovery.Initialize();
        NetworkDiscovery.StartAsClient();
    }

    void OnRecievedBroadcast(string fromAdress, string data)
    {
        serverIsFound = true;
    }

    // Update is called once per frame
    void Update () {
        Debug.Log("Server Found = " + serverIsFound);
    } 
}

Server -

    using UnityEngine;
using System.Collections;
using UnityEngine.Networking;

public class CreateServer : MonoBehaviour
{
    bool create;
    int minPort = 10000;
    int maxPort = 10010;
    int defaultPort = 10000;
    NetworkDiscovery NetworkDiscovery;

    void Start()
    {
        create = true;
        if (create == true)
        {
            int serverPort = createServer();
            if (serverPort != -1)
            {
                Debug.Log("Server created on port : " + serverPort);
            }
            else
            {
                Debug.Log("Failed to create Server");
            }
        }
        NetworkDiscovery = gameObject.AddComponent<NetworkDiscovery>();
        NetworkDiscovery.Initialize();
        NetworkDiscovery.StartAsServer();
    }


    //Creates a server then returns the port the server is created with. Returns -1 if server is not created
    int createServer()
    {
        int serverPort = -1;
        //Connect to default port

      bool serverCreated = NetworkServer.Listen(defaultPort);
        if (serverCreated)
        {
            serverPort = defaultPort;
            Debug.Log("Server Created with default port");
        }
        else
        {
            Debug.Log("Failed to create with the default port");
            //Try to create server with other port from min to max except the default port which we trid already
            for (int tempPort = minPort; tempPort <= maxPort; tempPort++)
            {
                //Skip the default port since we have already tried it
                if (tempPort != defaultPort)
                {
                    //Exit loop if successfully create a server
                    if (NetworkServer.Listen(tempPort))
                    {
                        serverPort = tempPort;
                        break;
                    }

                    //If this is the max port and server is not still created, show, failed to create server error
                    if (tempPort == maxPort)
                    {
                        Debug.LogError("Failed to create server");
                    }
                }
            }
        }
        return serverPort;
    }
}

These are the console logs with the debug logging

Thanks for reading I hope that you can realise where I have gone wrong or indeed how to complete said task otherwise. @Programmer

Answer 1

First of all you named each server and client script the-same name. You don't need OnRecievedBroadcast in the server code. You only need it in the client code. OnRecievedBroadcast is not being called on the client side because you did not override NetworkDiscovery. You must override it.

Here is a simple Discovering Code:

Client:

public class NetClient : NetworkDiscovery
{

    void Start()
    {
        startClient();
    }

    public void startClient()
    {
        Initialize();
        StartAsClient();
    }

    public override void OnReceivedBroadcast(string fromAddress, string data)
    {
         Debug.Log("Server Found");
    }
}

Server:

public class NetServer : NetworkDiscovery
{
    // Use this for initialization
    void Start()
    {
        Application.runInBackground = true;
        startServer();
    }

    //Call to create a server
    public void startServer()
    {
        int serverPort = createServer();
        if (serverPort != -1)
        {
            Debug.Log("Server created on port : " + serverPort);
            broadcastData = serverPort.ToString();
            Initialize();
            StartAsServer();
        }
        else
        {
            Debug.Log("Failed to create Server");
        }
    }

int minPort = 10000;
int maxPort = 10010;
int defaultPort = 10000;

//Creates a server then returns the port the server is created with. Returns -1 if server is not created
private int createServer()
{
    int serverPort = -1;
    //Connect to default port
    bool serverCreated = NetworkServer.Listen(defaultPort);
    if (serverCreated)
    {
        serverPort = defaultPort;
        Debug.Log("Server Created with deafault port");
    }
    else
    {
        Debug.Log("Failed to create with the default port");
        //Try to create server with other port from min to max except the default port which we trid already
        for (int tempPort = minPort; tempPort <= maxPort; tempPort++)
        {
            //Skip the default port since we have already tried it
            if (tempPort != defaultPort)
            {
                //Exit loop if successfully create a server
                if (NetworkServer.Listen(tempPort))
                {
                    serverPort = tempPort;
                    break;
                }

                //If this is the max port and server is not still created, show, failed to create server error
                if (tempPort == maxPort)
                {
                    Debug.LogError("Failed to create server");
                }
            }
        }
    }
    return serverPort;
}
}

The createServer() function is a function from your last question. I don't think you can have both server and client code running at the-same time in the Editor.

For testing, you must build the code in your pc with the server code/NetServer enabled. Run the built program then from your Editor you can run the client/NetClient code. This should discover game on the server.