C#操作共享内存

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Runtime.InteropServices;

namespace ConsoleApplication2

{

class Program

{

[DllImport("kernel32", SetLastError = true, CharSet = CharSet.Auto)]

public static extern IntPtr CreateFile(string lpFileName,

int dwDesiredAccess, int dwShareMode, IntPtr lpSecurityAttributes,

int dwCreationDisposition, int dwFlagsAndAttributes,

IntPtr hTemplateFile);

[DllImport("kernel32", SetLastError = true, CharSet = CharSet.Auto)]

public static extern IntPtr CreateFileMapping(IntPtr hFile,

IntPtr lpAttributes, int flProtect,

int dwMaximumSizeLow, int dwMaximumSizeHigh, string lpName);

[DllImport("Kernel32.dll", CharSet = CharSet.Auto)]

private static extern IntPtr OpenFileMapping(int dwDesiredAccess, [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle, string lpName);

[DllImport("Kernel32.dll", CharSet = CharSet.Auto)]

private static extern IntPtr MapViewOfFile(IntPtr hFileMapping, uint dwDesiredAccess, uint dwFileOffsetHigh, uint dwFileOffsetLow, uint dwNumberOfBytesToMap);

[DllImport("kernel32", EntryPoint = "GetLastError")]

public static extern int GetLastError();

[DllImport("Kernel32.dll", CharSet = CharSet.Auto)]

public static extern IntPtr CreateFileMapping(int hFile, IntPtr lpAttributes, uint flProtect, uint dwMaxSizeHi, uint dwMaxSizeLow, string lpName);

[DllImport("Kernel32.dll", CharSet = CharSet.Auto)]

public static extern bool UnmapViewOfFile(IntPtr pvBaseAddress);

[DllImport("Kernel32.dll", CharSet = CharSet.Auto)]

public static extern bool CloseHandle(IntPtr handle);

//原文链接：https://blog.csdn.net/gao271003105/article/details/81014094

public const int FILE_MAP_READ = 0x0004;

public static IntPtr fileMapping = IntPtr.Zero;

public static IntPtr mapView = IntPtr.Zero;

const int FILE_MAP_COPY = 0x0001;

const int FILE_MAP_WRITE = 0x0002;

// const int FILE_MAP_READ = 0x0004;

const int FILE_MAP_ALL_ACCESS = 0x0002 | 0x0004;

const int PAGE_READWRITE = 0x04;

const int INVALID_HANDLE_VALUE = -1;

const int ERROR_ALREADY_EXISTS = 183;

private bool bValid;

static bool m_bAlreadyExist = false;

static bool m_bInit = false;

static long m_MemSize = 0;

public void ShareMemoryHelper(string name, uint length)

{

bValid = GetShareMemoryMap(name, length);

}

public void ShareMemoryHelper()

{

}

// ~ShareMemoryHelper()

// {

// Close();

// }

public bool GetShareMemoryMap(string name, uint length)

{

m_MemSize = length;

fileMapping = OpenFileMapping(PAGE_READWRITE, false, name);

if (fileMapping == IntPtr.Zero)

{

return false;

}

mapView = MapViewOfFile(fileMapping, (uint)FILE_MAP_READ, 0, 0, length);

if (mapView == IntPtr.Zero)

{

int a = GetLastError();

return false;

}

m_bInit = true;

return true;

}

public static int CreateShareMemoryMap(string strName, long lngSize)

{

if (lngSize 0x00800000) lngSize = 0x00800000;

m_MemSize = lngSize;

if (strName.Length > 0)

{

fileMapping = CreateFileMapping(INVALID_HANDLE_VALUE, IntPtr.Zero, (uint)

PAGE_READWRITE, 0, (uint)lngSize, strName);

if (fileMapping == IntPtr.Zero)

{

return 2;

}

if (GetLastError() == ERROR_ALREADY_EXISTS)

{

m_bAlreadyExist = true;

}

else

{

m_bAlreadyExist = false;

}

mapView = MapViewOfFile(fileMapping, FILE_MAP_WRITE, 0, 0, (uint)lngSize);

if (mapView == IntPtr.Zero)

{

m_bInit = false;

CloseHandle(fileMapping);

return 3;

}

else

{

m_bInit = true;

if (m_bAlreadyExist == false)

{

}

}

}

else

{

return 1;

}

return 0;

}

public static int Write(byte[] bytData, int lngAddr, int lngSize)

{

if (lngAddr + lngSize > m_MemSize) return 2;

if (m_bInit)

{

Marshal.Copy(bytData, lngAddr, mapView, lngSize);

}

else

{

return 1;

}

return 0;

}

public static int Read(ref byte[] bytData, int lngAddr, int lngSize)

{

if (lngAddr + lngSize > m_MemSize) return 2;

if (m_bInit)

{

Marshal.Copy(mapView, bytData, lngAddr, lngSize);

}

else

{

return 1;

}

return 0;

}

public static void Close()

{

if (m_bInit)

{

UnmapViewOfFile(mapView);

CloseHandle(fileMapping);

}

}

static void Main(string[] args)

{

CreateShareMemoryMap("sss", 200);

byte[] ss = { 0,0,0,0,0 };

//Write(ss, 0, 2);

int k= Read(ref ss, 0, 5);

int st = ss[1];

Console.ReadLine();

Close();

}

}

}