Unity 与C#服务器 Socket的UDP通信
前言
这几天简单的研究了下Unity和服务器有关Socket的UDP通信，因为帧同步当中，UDP相比TCP是更适合的那种，因为UDP在网络环境较差时，波动更小，实时性也更高，可以更好的解决卡顿的问题（具体的小伙伴们可自行查阅资料）。当然使用UDP造成的开发量与开发难度会更大。在这里，我就先记录下自己这几天实现的udp简单的客户端与服务器的发送与接收功能的demo代码。
注意
1.本文是接着之前Socket通信的demo继续的，所以有些用的的东西可能在上一篇文章当中，大家需要的可以看一下：https://blog.csdn.net/wangjiangrong/article/details/80844392
2.相对tcp的强链接，udp是弱连接，客户端用udp给服务器发消息的时候，不需要和tcp那样先建立连接（connect）再发送，而是直接向服务器地址发送消息即可。类似我们发短信，知道对方手机号即可直接发送，而不用关心对方是否开机等信息。
3.目前研究下来，有两种写法，一种是用Socket对象，另一种是用UdpClient对象。两种写法我都试了，其中UdpClient可以成功的实现客户端和服务器的接收和发送，但是Socket只实现了客户端像服务器发送消息且服务器成功接收，但是客户端接收服务器消息则遇见了问题还没解决，有大佬懂的请指教一下。（研究下来是，Socket调用ReceiveFrom方法接收前，需要调用Bind方法，但是调用了Bind方法之后，SendTo方法那就报错了，因为SendTo方法不能调用前Bind。）
Socket.ReceiveFrom 方法：https://msdn.microsoft.com/zh-cn/library/7t7fzd26(v=vs.110).aspx
Socket.SendTo 方法：https://msdn.microsoft.com/zh-cn/library/1h691da7(v=vs.110).aspx?cs-save-lang=1&cs-lang=csharp#code-snippet-2
4.现在的代码只实现了一对一的通信，若要一对多，小伙伴们可以先研究研究多加些逻辑判断，后续补充有时间。
代码
下面就直接上代码了，大致思路就是，客户端和服务器都建立好Socket，并且服务器建立一个定时器用来给客户端定时发消息，，然后客户端像服务器发送消息，当服务器接收到消息的时候就开始向客户端定时发送消息。
因为没有连接，所以服务器也不知道客户端什么时候停止向客户端发送消息，向客户端发送消息的定时器需要何时停止，所以我目前的思路是，客户端要停止发送消息的时候可以给服务器发送一个指定消息，当服务器接收到指定消息的时候就停止再向客户端的消息发送，关掉定时器，这段功能暂时没有加。
首先是UdpClient写法的：
UdpClient
服务器代码
先上用一个类来存放常量
namespace Tool {
class SocketDefine {
public const int port = 8078;//端口号
public const string ip = "127.0.0.1";
}
}然后建立一个单例类来管理UdpClient
using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
namespace Tool {
class UdpManager : SingleClass {
UdpClient m_udpClient;
IPEndPoint m_clientIpEndPoint;//存放客户端地址
Thread m_connectThread;//接收客户端消息的线程
byte[] m_result = new byte[1024];//存放接收到的消息
bool m_isStartSend;//接收到客户端消息的时候才可以发送
//初始化
public void Start() {
m_isStartSend = false;
IPEndPoint ipEnd = new IPEndPoint(IPAddress.Parse(SocketDefine.ip), SocketDefine.port);
m_udpClient = new UdpClient(ipEnd);
//定义客户端
m_clientIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
Console.WriteLine("等待连接数据");
//开启一个线程连接
m_connectThread = new Thread(new ThreadStart(Receive));
m_connectThread.Start();
System.Timers.Timer t = new System.Timers.Timer(3000);//实例化Timer类，设置间隔时间为10000毫秒
t.Elapsed += new System.Timers.ElapsedEventHandler(SendToClient);//到达时间的时候执行事件
t.AutoReset = true;//设置是执行一次（false）还是一直执行(true)
t.Enabled = true;//是否执行System.Timers.Timer.Elapsed事件
}
public void SendToClient(object source, System.Timers.ElapsedEventArgs e) {
if(m_isStartSend) {
Send("server msg 111");
}
}
public void Send(string data) {
try {
Console.WriteLine("send to " + m_clientIpEndPoint + " " + data);
NetBufferWriter writer = new NetBufferWriter();
writer.WriteString(data);
m_udpClient.Send(writer.Finish(), writer.finishLength, m_clientIpEndPoint);
} catch(Exception ex) {
Console.WriteLine("send error " + ex.Message);
}
}
//服务器接收
void Receive() {
while(true) {
try {
m_result = new byte[1024];
m_result = m_udpClient.Receive(ref m_clientIpEndPoint);
NetBufferReader reader = new NetBufferReader(m_result);
string data = reader.ReadString();
Console.WriteLine(m_clientIpEndPoint + " 数据内容：{0}", data);
m_isStartSend = true;
} catch(Exception ex) {
Console.WriteLine("receive error " + ex.Message);
Close();
}
}
}
//连接关闭
void Close() {
m_isStartSend = false;
//关闭线程
if(m_connectThread != null) {
m_connectThread.Interrupt();
m_connectThread.Abort();
}
if(m_udpClient != null) {
m_udpClient.Close();
m_udpClient.Dispose();
}
Console.WriteLine("断开连接");
}
}
} 最后我们在程序主入口调用即可
using System;
using Tool;
namespace MyApp {
class Program {
static void Main(string[] args) {
UdpManager.instance.Start();
Console.ReadLine();
}
}
}客户端代码
因为所有的通信都涉及连接，发送，接收，断开连接（当然udp不存在连接，所以连接和断开连接只是做一些初始化和清理操作），所以定义一个接口ISocket如下
namespace Tool {
public interface ISocket {
//是否已连接的标识
bool IsConnected();
//连接指定IP和端口的服务器
void Connect(string ip, int port);
//发送数据给服务器
void SendMessage(string data);
//断开连接
void Disconnect();
//接收服务器端Socket的消息
void RecieveMessage();
}
}然后一样是我们的客户端UdpClient管理单例类，这里需要注意一点的是UdpClient初始化的时候UdpClient(0)端口要设置为0，不然后面接收的时候会报错提供了一个无效的参数
using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using UnityEngine;
namespace Tool {
public class UdpManager : SingleClass, ISocket {
public delegate void OnGetReceive(string message);//接收到消息的委托
public OnGetReceive onGetReceive;
byte[] m_result = new byte[1024];
Thread m_connectThread;
UdpClient m_udpClient;
IPEndPoint m_serverIPEndPoint;
IPEndPoint m_recieveIPEndPoint;
bool m_isConnected;
//是否已连接的标识
public bool IsConnected() {
return m_isConnected;
}
//udp是无连接的，所以方法里只做了一些初始化操作
public void Connect(string ip, int port) {
m_serverIPEndPoint = new IPEndPoint(IPAddress.Parse(ip), port);
m_udpClient = new UdpClient(0);//!!!!!主要一定要设置port为0，不然无法接收到服务器的消息
m_isConnected = true;
m_recieveIPEndPoint = new IPEndPoint(IPAddress.Any, 0);
//开启一个线程连接
m_connectThread = new Thread(new ThreadStart(RecieveMessage));
m_connectThread.Start();
}
public void SendMessage(string data) {
if(IsConnected()) {
NetBufferWriter writer = new NetBufferWriter();
Debug.Log("SendMessage " + data);
writer.WriteString(data);
m_udpClient.Send(writer.Finish(), writer.finishLength, m_serverIPEndPoint);
}
}
public void Disconnect() {
if(IsConnected()) {
m_isConnected = false;
}
if(m_connectThread != null) {
m_connectThread.Interrupt();
m_connectThread.Abort();
}
if(m_udpClient != null) {
m_udpClient.Close();
}
}
public void RecieveMessage() {
while(IsConnected()) {
try {
m_result = new byte[1024];
//m_udpClient的port不是0的时候，会报错，无效参数
m_result = m_udpClient.Receive(ref m_recieveIPEndPoint);
NetBufferReader reader = new NetBufferReader(m_result);
string msg = reader.ReadString();
Debug.Log("RecieveMessage " + msg);
} catch(Exception e) {
Debug.Log("recieve error " + e.Message);
Disconnect();
}
}
}
}
} 最后我们调用UdpManager.instance.Connect("127.0.0.1", 8078);和UdpManager.instance.SendMessage(content);即可。
效果图如下：
Socket
代码也贴一下，又需要的朋友可以看看，基本类似，使用方法也一样。
服务器代码
using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
namespace Tool {
class UdpSocketManager : SingleClass {
Socket m_serverSocket;
EndPoint m_clientEndPoint;
byte[] m_result = new byte[1024];
int m_resultLength;
Thread m_connectThread;
bool m_isStartSend;
public void Start() {
m_isStartSend = false;
IPEndPoint ipEnd = new IPEndPoint(IPAddress.Parse(SocketDefine.ip), SocketDefine.port);
m_serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
m_serverSocket.Bind(ipEnd);
//定义客户端
IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
m_clientEndPoint = (EndPoint)sender;
Console.WriteLine("等待连接数据");
//开启一个线程连接
m_connectThread = new Thread(new ThreadStart(Receive));
m_connectThread.Start();
System.Timers.Timer t = new System.Timers.Timer(1000);//实例化Timer类，设置间隔时间为10000毫秒
t.Elapsed += new System.Timers.ElapsedEventHandler(SendToClient);//到达时间的时候执行事件
t.AutoReset = true;//设置是执行一次（false）还是一直执行(true)
t.Enabled = true;//是否执行System.Timers.Timer.Elapsed事件
}
public void SendToClient(object source, System.Timers.ElapsedEventArgs e) {
if(m_isStartSend) {
Send("server msg 111");
}
}
public void Send(string data) {
try {
Console.WriteLine("send to " + m_clientEndPoint + " " + data);
NetBufferWriter writer = new NetBufferWriter();
writer.WriteString(data);
m_serverSocket.SendTo(writer.Finish(), SocketFlags.None, m_clientEndPoint);
} catch(Exception ex) {
Console.WriteLine("send error " + ex.Message);
}
}
//服务器接收
void Receive() {
while(true) {
try {
m_result = new byte[1024];
m_resultLength = m_serverSocket.ReceiveFrom(m_result, ref m_clientEndPoint);
NetBufferReader reader = new NetBufferReader(m_result);
string data = reader.ReadString();
Console.WriteLine(m_clientEndPoint + " 数据内容：{0}", data);
m_isStartSend = true;
} catch(Exception ex) {
Console.WriteLine("receive error " + ex.Message);
}
}
}
//连接关闭
public void Close() {
m_isStartSend = false;
//关闭线程
if(m_connectThread != null) {
m_connectThread.Interrupt();
m_connectThread.Abort();
}
//最后关闭socket
if(m_serverSocket != null) {
m_serverSocket.Close();
}
Console.WriteLine("断开连接");
}
}
}
客户端代码
using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using UnityEngine;
namespace Tool {
public class UdpSocketManager : SingleClass, ISocket {
Socket m_clientSocket;
EndPoint serverEnd;
IPEndPoint m_ipEndPoint;
Thread m_connectThread;
byte[] m_result = new byte[1024];
int m_resultLength = 0;
bool m_isConnected;
public UdpSocketManager() {
m_clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
}
public bool IsConnected() {
return m_isConnected;
}
IPEndPoint endPoint;
public void Connect(string ip, int port) {
m_ipEndPoint = new IPEndPoint(IPAddress.Parse(ip), port);
m_isConnected = true;
IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
serverEnd = (EndPoint)sender;
//RecieveMessage需要bind https://msdn.microsoft.com/zh-cn/library/7t7fzd26(v=vs.110).aspx
//string ip4 = "";
//IPAddress[] ips = Dns.GetHostAddresses(Dns.GetHostName()); //Dns.GetHostName()获取本机名Dns.GetHostAddresses()根据本机名获取ip地址组
//foreach(IPAddress ipp in ips) {
// if(ipp.AddressFamily == AddressFamily.InterNetwork) {
// ip4 = ipp.ToString();
// }
//}
//IPEndPoint endPoint = new IPEndPoint(IPAddress.Parse(ip4), 11000);
//m_clientSocket = new Socket(endPoint.Address.AddressFamily, SocketType.Dgram, ProtocolType.Udp);
//m_clientSocket.Bind(endPoint);
//m_connectThread = new Thread(new ThreadStart(RecieveMessage));
//m_connectThread.Start();
}
public void Disconnect() {
if(IsConnected()) {
m_isConnected = false;
}
if(m_connectThread != null) {
m_connectThread.Interrupt();
m_connectThread.Abort();
}
if(m_clientSocket != null) {
m_clientSocket.Close();
}
}
//udp不需要先于对方建立连接关系，直接向对方ip发送消息即可
public void SendMessage(string data) {
if(IsConnected()) {
Debug.Log("SendMessage " + data);
NetBufferWriter writer = new NetBufferWriter();
writer.WriteString(data);
m_clientSocket.SendTo(writer.Finish(), SocketFlags.None, m_ipEndPoint);
}
}
public void RecieveMessage() {
while(IsConnected()) {
try {
m_result = new byte[1024];
m_resultLength = m_clientSocket.ReceiveFrom(m_result, ref serverEnd);
NetBufferReader reader = new NetBufferReader(m_result);
string ss = reader.ReadString();
Debug.Log("RecieveMessage " + ss);
} catch(Exception ex) {
Debug.Log("RecieveMessage error " + ex.Message);
Disconnect();
break;
}
}
}
}
}