----tcp（傳輸 控制 協議）是可靠消息：三次握手（發給對方，對方發給自己，證明對方接到消息，在發給對方，說明自己能接到對方消息，這樣就都知道了）：tcp:每發送一次消息，對方都會回復，證明接受到了所以是可靠地；包含許多校驗，效率差；

---（UDP：用戶 數據報 協議）數據報文服務：消息發送給對方就完事了，不管你是否接收到；

不可靠，但是效率高；

-----應用層協議：Http,Ftp,Popj SMTp

-----傳輸層：TCP，ICMP，UDP

-----網絡層：IP,ARP ;

socket是應用層和傳輸層之間的交互；

---端口：三類：工人端口、注冊端口、動態私有端口（這些可以用）

---套接字指的是socket;封裝的網絡插口；

----服務端：1創建socket,綁定端口和ip;打開監聽，接受客戶端；

----客戶端：創建socket,鏈接服務器，創建ip端口，進行鏈接；

--服務器端接受科幻段消息時，創建socketProxy對象，占用系統自動分配的

一個端口，發送消息時重新占用新的端口，原來端口繼續監聽；

--說白了，監聽端口收到消息創建新的socket對象，并綁定新的端口進行通信

--這個端口就幫死了，傳遞接受都用這一個端口），

而監聽端口繼續監聽，

? public partial class Form1 : Form

??? {

??????? List<Socket> list = new List<Socket>();

??????? public Form1()

??????? {

??????????? InitializeComponent();

??????? }

??????? private void Form1_Load(object sender, EventArgs e)

??????? {

?

??????? }

?

??????? private void button1_Click(object sender, EventArgs e)

??????? {

??????????? string ip = "192.168.1.1";

??????????? //創建ip地址：

??????????? IPAddress ipAddress = IPAddress.Parse(ip);

??????????? //創建端口

??????????? IPEndPoint ipPoint = new IPEndPoint(ipAddress, 3030);

??????????? //穿點套接字：

??????????? //參數1：尋址方式；參數2：socket傳輸方式:stream tcp方式，Dgram:數據報方式，第三個參數：協議

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

??????????? //綁定端口和ip

??????????? s.Bind(ipPoint);

??????????? //開始監聽：（請求最大連接長度）,s為委托參數；

??????????? ThreadPool.QueueUserWorkItem(new WaitCallback(Accept), s);

?

??????? }

??????? public void Accept(object obj)

??????? {

??????????? Socket socket = (Socket)obj;

??????????? while (true)

??????????? {

??????????????? //接受客戶端的一個連接創建代理套接字

??????????????? Socket proxys = socket.Accept();

??????????????? //存儲這些通信管道；

??????????????? list.Add(proxys);

??????????????? //獲取套接字端口和ip；

??????????????? // proxys.RemoteEndPoint.ToString();

??????????? ????ThreadPool.QueueUserWorkItem(new WaitCallback(AcceptStarts), proxys);

??????????? }

??????? }

??????? public void AcceptStarts(object obj)

??????? {

??????????? Socket socket = (Socket)obj;

??????????? while (true)

??????????? {

??????????????? //通過判斷異常來判斷，是否客戶端已中斷，來關閉服務端的socket;

??????????????? try

??????????????? {

??????????????????? byte[] buffer = new byte[1024 * 1024];

??????????????????? int realLength = socket.Receive(buffer, 0, buffer.Length, SocketFlags.None);

??????????????????? string strResult = Encoding.Default.GetString(buffer, 0, buffer.Length);

??????????????? }

??????????????? catch

??????????????? {

??????????????????? socket.Close();

??????????????????? //異常已失效斷開的socket;

??????????????????? list.Remove(socket);

??????????????? }

???? ???????}

??????? }

?

??????? private void button2_Click(object sender, EventArgs e)

??????? {

??????????? //發送消息

??????????? foreach (Socket s in list)

??????????? {

??????????????? //防止socket斷開失效；

??????????????? try

??????????????? {

??????????????????? string str = "發送內容";

??????????????????? byte[] bytes = Encoding.Default.GetBytes(str);

??????????????????? s.Send(bytes, SocketFlags.None);

??????????????? }

??????????????? catch

??????????????? {

??????????????????? s.Close();

????? ??????????????//異常已失效斷開的socket;

??????????????????? list.Remove(s);

??????????????? }

??????????? }

??????? }

??? }

--------------------客戶端

?public partial class 客戶端 : Form

??? {

??????? public Socket CurrentSocket { get; set; }

??????? public 客戶端()

????? ??{

??????????? InitializeComponent();

??????? }

??????? private void button1_Click(object sender, EventArgs e)

??????? {

??????????? Socket socket =null;

??????????? try

??????????? {

??????????????? IPAddress ipAddress = IPAddress.Parse("192.168.1.1");

??????????????? IPEndPoint endpoint = new IPEndPoint(ipAddress, 8080);

??????????????? //創建socket;

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

??????????????? socket.Connect(endpoint);

????????????? ??CurrentSocket = socket;

??????????? }

??????????? catch

??????????? {

??????????????? if (socket != null)

??????????????? {

??????????????????? socket.Dispose();

??????????????? }

??????????? }

??????? }

?

??????? private void button2_Click(object sender, EventArgs e)

??????? {

??????????? byte[] bytes = Encoding.Default.GetBytes("sdfsdfd");

??????????? if (CurrentSocket != null)

??????????? {

??????????????? try

??????????????? {

??????????????????? CurrentSocket.Send(bytes, 0, bytes.Length, 0);

??????????????? }

??????????????? catch

??????????????? {

??????????????????? CurrentSocket.Dispose();

??????????????? }

??????????? }

??????? }

??? }

socket傳遞的數據都是byte[]數組類型；

服務器端通過捕獲異常來知道客戶端關閉連接；

? Encoding.Default.GetBytes();

----503錯誤：訪問人數過多

--------

-------------字節塊拷貝： //字節塊拷貝：

??????????????? byte[] a = new byte[1024];

??????????????? byte[] b = new byte[1025];

??????????????? b[0] =1;//這樣可以說是自定義協議；第一個位代表什么意思；接受時根據第一個字節判斷是傳送的什么數據文件（比如1代表圖片）

??????????????? Buffer.BlockCopy(a, 0, b,1,a.Length);

---魔鬼數字：1代表什么2代表什么，千萬別使用，通常使用枚舉；

C# socket通信隨記回顧