SocketException: 由于套接字没有连接并且(当使用一个 sendto 调用发送数据报套接字时)没有提供地址，发送或接收数据的请求没有被接受。

yuanyuanluoluo 2019-03-14 05:45:50

服务器往客户端发送消息的时候报这个错：
错误定在：//异步发送消息请求
server_socket.BeginSend(sendData, 0, sendData.Length, SocketFlags.None, new System.AsyncCallback(SendToServer), server_socket);

但是这是我按着客户端发消息的代码一点点改的不应该有错啊，百思不得原因，希望大佬助我！！！

贴上代码：

using UnityEngine;

using System.Collections;

using System.Net.Sockets;

using System.Net;

using System.Text;



public class ServerScript : MonoBehaviour

{

	//收到消息后的委托回调

	public delegate void ReceiveCallBack(string content);

	private string receive_str;

	Socket server;

	string msg = "";

	//服务器端收到消息的存储空间

	byte[] ReceiveBuffer = new byte[1024];

	//服务器收到消息后的回调委托

	private ReceiveCallBack callback;

	private Socket server_socket;



	private readonly object locker = new object();

	// Use this for initialization

	void Start()

	{

		//初始化服务器

		InitServer((string content) => {

			receive_str = content;

		});

	}

	

	//初始化服务器信息

	public void InitServer(ReceiveCallBack cb)

	{

		this.callback = cb;

		// 1.

		 server_socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

		// 2.

		IPEndPoint endPoint = new IPEndPoint(IPAddress.Any, 5001);

		// 3.

		server_socket.Bind(endPoint);

		// 4.

		server_socket.Listen(10);

		// 5.开始异步等待客户端的请求链接

		server_socket.BeginAccept(new System.AsyncCallback(Accept), server_socket);



		this.callback("开启服务器" + endPoint.ToString());

	}

	

	void OnGUI()

	{

		if (receive_str != null)

		{

			GUILayout.Label(receive_str);

		}

		msg = GUI.TextField(new Rect(0, 0, 500, 40), msg);

		if (GUI.Button(new Rect(0, 50, 100, 30), "Send"))

		{

			SendMessage(msg);

		}

	}

	//接受到客户端的链接请求后的回调函数

	void Accept(System.IAsyncResult ar)

	{

		//获取正在工作的Socket对象 

		Socket socket = ar.AsyncState as Socket;

		//存储异步操作的信息，以及用户自定义的数据  

		Socket worker = socket.EndAccept(ar);

		SocketError error;

		//开始异步接收客户端发送消息内容

		worker.BeginReceive(ReceiveBuffer, 0, ReceiveBuffer.Length, SocketFlags.None, new System.AsyncCallback(Receive), worker);

		//继续异步等待新的客户端链接请求

		socket.BeginAccept(new System.AsyncCallback(Accept), socket);

	}

	//服务端收到客户端的消息后的回调函数

	void Receive(System.IAsyncResult ar)

	{

			//获取正在工作的Socket对象

			Socket worker = ar.AsyncState as Socket;

			int ByteRead = 0;

			try

			{

				ByteRead = worker.EndReceive(ar);

			}

			catch (System.Exception ex)

			{

				this.callback(ex.ToString());

			}

			if (ByteRead > 0)

			{

				string Content = Encoding.Default.GetString(ReceiveBuffer);

				this.callback(Content);

			}

			//继续异步等待客户端的发送消息请求

			worker.BeginReceive(ReceiveBuffer, 0, ReceiveBuffer.Length, SocketFlags.None, new System.AsyncCallback(Receive), worker);

	}

	public void SendMessage(string message)

	{

		if (message == null)

			return;



		message += "\r\n";

		byte[] sendData = Encoding.UTF8.GetBytes(message);

		//异步发送消息请求

		server_socket.BeginSend(sendData, 0, sendData.Length, SocketFlags.None, new System.AsyncCallback(SendToServer), server_socket);

	}

	//发送消息结束的回调函数

	void SendToServer(System.IAsyncResult ar)

	{

		Socket worker = ar.AsyncState as Socket;

		worker.EndSend(ar);

	}

}