Unity3d and UdpClient

Question

I want to read UDP Packages into Unity3d using Sockets. The UDP Packages are sent by another C# App, which is not a Unity App. Therefore, I attach the following script ( original source ) to one of my game objects. Unfortunately, when I run my project, Unity freezes. Can anyone tell me why?

using UnityEngine;
using System.Collections;
using System;
using System.Threading;
using System.Net;
using System.Net.Sockets;
using System.Text;

public class InputUDP : MonoBehaviour
{
    // read Thread
    Thread readThread;

    // udpclient object
    UdpClient client;

    // port number
    public int port = 9900;

    // UDP packet store
    public string lastReceivedPacket = "";
    public string allReceivedPackets = ""; // this one has to be cleaned up from time to time

    // start from unity3d
    void Start()
    {
        // create thread for reading UDP messages
        readThread = new Thread(new ThreadStart(ReceiveData));
        readThread.IsBackground = true;
        readThread.Start();
    }

    // Unity Update Function
    void Update()
    {
        // check button "s" to abort the read-thread
        if (Input.GetKeyDown("q"))
            stopThread();
    }

    // Unity Application Quit Function
    void OnApplicationQuit()
    {
        stopThread();
    }

    // Stop reading UDP messages
    private void stopThread()
    {
        if (readThread.IsAlive)
        {
            readThread.Abort();
        }
        client.Close();
    }

    // receive thread function
    private void ReceiveData()
    {
        client = new UdpClient(port);
        while (true)
        {
            try
            {
                // receive bytes
                IPEndPoint anyIP = new IPEndPoint(IPAddress.Any, 0);
                byte[] data = client.Receive(ref anyIP);

                // encode UTF8-coded bytes to text format
                string text = Encoding.UTF8.GetString(data);

                // show received message
                print(">> " + text);

                // store new massage as latest message
                lastReceivedPacket = text;

                // update received messages
                allReceivedPackets = allReceivedPackets + text;

            }
            catch (Exception err)
            {
                print(err.ToString());
            }
        }
    }

    // return the latest message
    public string getLatestPacket()
    {
        allReceivedPackets = "";
        return lastReceivedPacket;
    }
}

Note: I want to use IPC to connect our game logic with Unity (using unity as nothing but a rendering engine). The C# application contains the game logic. The data that I need to transfer comprises all possible control states, such as position/orientation of different players/objects etc. Both applications are running on the same machine.

Answer 1

Your Receive is blocking by default - so the Update call is waiting on Receive to complete.

Add this after you create your client:

client.Client.Blocking = false;

Answer 2

添加接收超时

client.Client.ReceiveTimeout = 1000;