C# Socket 入门5 UPD 结构体 与 C++ 通信

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1. 同样， 我们先看看这一个比简单的 结构体


代码




using System;

using System.Collections.Generic;

using System.Text;

using System.Runtime.InteropServices;

namespace CSharp_Socket_5

{

/// <summary>

/// 通信消息格式

/// </summary>

[Serializable]

[StructLayout(LayoutKind.Sequential, Pack = 1)]

public struct CP2PMessage

{

public ushort id;

}

}




C++ 版本

struct CP2PMessage

{

WORD id;

};

2. C# 服务端， 和之前的一样滴~~ 看来是不是很亲切也~


代码




using System;

using System.Collections.Generic;

using System.Text;

using System.Net.Sockets;

using System.Net;

using System.Runtime.InteropServices;

namespace CSharp_Socket_5

{

class Program

{

/// <summary>

/// 服务端

/// </summary>

/// <param name="args"></param>

static void Main(string[] args)

{

// 1.创建套节字

Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

// 2.填充IP

IPEndPoint ipe = new IPEndPoint(IPAddress.Any, 4321);

// 3.绑定

socket.Bind(ipe);

// 等待客户机连接

Console.WriteLine("这个服务器, host name is {0}", Dns.GetHostName());

Console.WriteLine("等待客户端连接....");

// 4.得客户机IP

IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);

EndPoint remote = (EndPoint)sender;

// 5.接收客户机数据

byte[] buffer = new byte[1024];

socket.ReceiveFrom(buffer, ref remote);

CP2PMessage msg = new CP2PMessage();

msg = (CP2PMessage)BytesToStruct(buffer, msg.GetType());

Console.WriteLine("接C++收的值为:{0}", msg.id);

Console.ReadKey();

}

public static byte[] StructToBytes(object obj)

{

int size = Marshal.SizeOf(obj);

byte[] bytes = new byte[size];

IntPtr structPtr = Marshal.AllocHGlobal(size); //分配结构体大小的内存空间

Marshal.StructureToPtr(obj, structPtr, false); //将结构体拷到分配好的内存空间

Marshal.Copy(structPtr, bytes, 0, size); //从内存空间拷到byte数组

Marshal.FreeHGlobal(structPtr); //释放内存空间

return bytes;

}

public static object BytesToStruct(byte[] bytes, Type type)

{

int size = Marshal.SizeOf(type);

if (size > bytes.Length)

return null;

IntPtr structPtr = Marshal.AllocHGlobal(size); //分配结构大小的内存空间

Marshal.Copy(bytes, 0, structPtr, size); //将byte数组拷到分配好的内存空间

object obj = Marshal.PtrToStructure(structPtr, type);

Marshal.FreeHGlobal(structPtr);

return obj;

}

}

}




3. 重点了，，C++ 客户端


代码




#include <winsock2.h>

#include <stdio.h>

#pragma comment(lib, "WS2_32.lib")

struct CP2PMessage

{

WORD id;

};

void main()

{

//初始化 WS2_32.dll

WSADATA wsaData;

::WSAStartup(MAKEWORD(2,2), & wsaData);

// 1.创建套节字

SOCKET s = ::socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);

// 2.填写服务器IP

sockaddr_in sin;

sin.sin_family = AF_INET;

sin.sin_port = ::htons(4321);

sin.sin_addr.S_un.S_addr = ::inet_addr("127.0.0.1");

// 3. 向服务器发送消息

CP2PMessage msg;

msg.id = 10;

::sendto(s, (char*)&msg, sizeof(msg), 0, (sockaddr*)&sin, sizeof(sin));

}




4. 完成了，，，