C#进程间通信（共享内存）进程间通信的⽅式有很多，常⽤的⽅式有：1.共享内存（内存映射⽂件，共享内存DLL）。
2.命名管道和匿名管道。
3.发送消息本⽂是记录共享内存的⽅式进⾏进程间通信，⾸先要建⽴⼀个进程间共享的内存地址，创建好共享内存地址后，⼀个进程向地址中写⼊数据，另外的进程从地址中读取数据。
在数据的读写的过程中要进⾏进程间的同步。
进程间数据同步可以有以下的⽅式1. 互斥量Mutex2. 信号量Semaphore3. 事件Event本⽂中进程间的同步采⽤信号量Semaphore的⽅式同步思想类似于操作系统中⽣产者和消费者问题的处理⽅式。
在A进程中创建共享内存，并开启⼀个线程⽤来读取B进程向共享内存中写⼊的数据，定义两个信号量进⾏读写互斥同步A进程中的程序代码using System;using System.Collections.Generic;using ponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Runtime.InteropServices;using System.Threading;using System.Diagnostics;namespace AppOne{public partial class AppOneMain : Form{const int INVALID_HANDLE_VALUE = -1;const int PAGE_READWRITE = 0x04;[DllImport("User32.dll")]private static extern bool ShowWindowAsync(IntPtr hWnd, int cmdShow);[DllImport("User32.dll")]private static extern bool SetForegroundWindow(IntPtr hWnd);//共享内存[DllImport("Kernel32.dll", EntryPoint = "CreateFileMapping")]private static extern IntPtr CreateFileMapping(IntPtr hFile, //HANDLE hFile,UInt32 lpAttributes,//LPSECURITY_ATTRIBUTES lpAttributes, //0UInt32 flProtect,//DWORD flProtectUInt32 dwMaximumSizeHigh,//DWORD dwMaximumSizeHigh,UInt32 dwMaximumSizeLow,//DWORD dwMaximumSizeLow,string lpName//LPCTSTR lpName);[DllImport("Kernel32.dll", EntryPoint = "OpenFileMapping")]private static extern IntPtr OpenFileMapping(UInt32 dwDesiredAccess,//DWORD dwDesiredAccess,int bInheritHandle,//BOOL bInheritHandle,string lpName//LPCTSTR lpName);const int FILE_MAP_ALL_ACCESS = 0x0002;const int FILE_MAP_WRITE = 0x0002;[DllImport("Kernel32.dll", EntryPoint = "MapViewOfFile")]private static extern IntPtr MapViewOfFile(IntPtr hFileMappingObject,//HANDLE hFileMappingObject,UInt32 dwDesiredAccess,//DWORD dwDesiredAccessUInt32 dwFileOffsetHight,//DWORD dwFileOffsetHigh,UInt32 dwFileOffsetLow,//DWORD dwFileOffsetLow,UInt32 dwNumberOfBytesToMap//SIZE_T dwNumberOfBytesToMap);[DllImport("Kernel32.dll", EntryPoint = "UnmapViewOfFile")]private static extern int UnmapViewOfFile(IntPtr lpBaseAddress);[DllImport("Kernel32.dll", EntryPoint = "CloseHandle")]private static extern int CloseHandle(IntPtr hObject);private Semaphore m_Write; //可写的信号private Semaphore m_Read; //可读的信号private IntPtr handle; //⽂件句柄private IntPtr addr; //共享内存地址uint mapLength; //共享内存长//线程⽤来读取数据Thread threadRed;public AppOneMain(){InitializeComponent();init();}///<summary>///初始化共享内存数据创建⼀个共享内存///</summary>privatevoid init(){m_Write = new Semaphore(1, 1, "WriteMap");//开始的时候有⼀个可以写m_Read = new Semaphore(0, 1, "ReadMap");//没有数据可读mapLength = 1024;IntPtr hFile = new IntPtr(INVALID_HANDLE_VALUE);handle = CreateFileMapping(hFile, 0, PAGE_READWRITE, 0, mapLength, "shareMemory"); addr = MapViewOfFile(handle, FILE_MAP_ALL_ACCESS, 0, 0, 0);//handle = OpenFileMapping(0x0002, 0, "shareMemory");//addr = MapViewOfFile(handle, FILE_MAP_ALL_ACCESS, 0, 0, 0);threadRed = new Thread(new ThreadStart(ThreadReceive));threadRed.Start();}///<summary>///线程启动从共享内存中获取数据信息///</summary>private void ThreadReceive(){myDelegate myI = new myDelegate(changeTxt);while (true){try{//m_Write = Semaphore.OpenExisting("WriteMap");//m_Read = Semaphore.OpenExisting("ReadMap");//handle = OpenFileMapping(FILE_MAP_WRITE, 0, "shareMemory");//读取共享内存中的数据：//是否有数据写过来m_Read.WaitOne();//IntPtr m_Sender = MapViewOfFile(handle, FILE_MAP_ALL_ACCESS, 0, 0, 0);byte[] byteStr = new byte[100];byteCopy(byteStr, addr);string str = Encoding.Default.GetString(byteStr, 0, byteStr.Length);/////调⽤数据处理⽅法处理读取到的数据m_Write.Release();}catch (WaitHandleCannotBeOpenedException){continue;//Thread.Sleep(0);}}}//不安全的代码在项⽬⽣成的选项中选中允许不安全代码static unsafe void byteCopy(byte[] dst, IntPtr src){fixed (byte* pDst = dst){byte* pdst = pDst;byte* psrc = (byte*)src;while ((*pdst++ = *psrc++) != '\0');}}}}B进程向共享内存中写⼊的数据using System;using System.Collections.Generic;using ponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Runtime.InteropServices;using System.Threading;namespace AppTwo{public partial class AppTwoMain : Form{const int INVALID_HANDLE_VALUE = -1;const int PAGE_READWRITE = 0x04;//共享内存[DllImport("Kernel32.dll", EntryPoint = "CreateFileMapping")]private static extern IntPtr CreateFileMapping(IntPtr hFile, //HANDLE hFile,UInt32 lpAttributes,//LPSECURITY_ATTRIBUTES lpAttributes, //0UInt32 flProtect,//DWORD flProtectUInt32 dwMaximumSizeHigh,//DWORD dwMaximumSizeHigh,UInt32 dwMaximumSizeLow,//DWORD dwMaximumSizeLow,string lpName//LPCTSTR lpName);[DllImport("Kernel32.dll", EntryPoint = "OpenFileMapping")]private static extern IntPtr OpenFileMapping(UInt32 dwDesiredAccess,//DWORD dwDesiredAccess,int bInheritHandle,//BOOL bInheritHandle,string lpName//LPCTSTR lpName);const int FILE_MAP_ALL_ACCESS = 0x0002;const int FILE_MAP_WRITE = 0x0002;[DllImport("Kernel32.dll", EntryPoint = "MapViewOfFile")]private static extern IntPtr MapViewOfFile(IntPtr hFileMappingObject,//HANDLE hFileMappingObject,UInt32 dwDesiredAccess,//DWORD dwDesiredAccessUInt32 dwFileOffsetHight,//DWORD dwFileOffsetHigh,UInt32 dwFileOffsetLow,//DWORD dwFileOffsetLow,UInt32 dwNumberOfBytesToMap//SIZE_T dwNumberOfBytesToMap);[DllImport("Kernel32.dll", EntryPoint = "UnmapViewOfFile")]private static extern int UnmapViewOfFile(IntPtr lpBaseAddress);[DllImport("Kernel32.dll", EntryPoint = "CloseHandle")]private static extern int CloseHandle(IntPtr hObject);private Semaphore m_Write; //可写的信号private Semaphore m_Read; //可读的信号private IntPtr handle; //⽂件句柄private IntPtr addr; //共享内存地址uint mapLength; //共享内存长Thread threadRed;public AppTwoMain(){InitializeComponent();//threadRed = new Thread(new ThreadStart(init));//threadRed.Start();mapLength = 1024;}private void button1_Click(object sender, EventArgs e){try{m_Write = Semaphore.OpenExisting("WriteMap");m_Read = Semaphore.OpenExisting("ReadMap");handle = OpenFileMapping(FILE_MAP_WRITE, 0, "shareMemory");addr = MapViewOfFile(handle, FILE_MAP_ALL_ACCESS, 0, 0, 0);m_Write.WaitOne();byte[] sendStr = Encoding.Default.GetBytes(textBox1.Text.ToString() + '\0');//如果要是超长的话，应另外处理，最好是分配⾜够的内存if (sendStr.Length < mapLength)Copy(sendStr, addr);m_Read.Release();}catch (WaitHandleCannotBeOpenedException){MessageBox.Show("不存在系统信号量!");return;}}static unsafe void Copy(byte[] byteSrc, IntPtr dst) {fixed (byte* pSrc = byteSrc){byte* pDst = (byte*)dst;byte* psrc = pSrc;for (int i = 0; i < byteSrc.Length; i++){*pDst = *psrc;pDst++;psrc++;}}}}}。
