C# 共享内存（转）

以下是一个C#操作内存的一个类，只要将下面的类添加到相应的项目中，该项目就可以对内存进行直接操作！

using System.Runtime.InteropServices;    //添加如下命名空间 需要是用 DllImport

public class ShareMemLib
    {

[DllImport("user32.dll", CharSet = CharSet.Auto)]

public static extern IntPtr SendMessage(IntPtr hWnd, int Msg, int wParam, IntPtr lParam);

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

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

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

[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);

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

public static extern int GetLastError();

const int ERROR_ALREADY_EXISTS = 183;

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_READONLY = 0x02;

const int PAGE_READWRITE = 0x04;

const int PAGE_WRITECOPY = 0x08;

const int PAGE_EXECUTE = 0x10;

const int PAGE_EXECUTE_READ = 0x20;

const int PAGE_EXECUTE_READWRITE = 0x40;

const int SEC_COMMIT = 0x8000000;

const int SEC_IMAGE = 0x1000000;

const int SEC_NOCACHE = 0x10000000;

const int SEC_RESERVE = 0x4000000;

const int INVALID_HANDLE_VALUE = -1;

IntPtr m_hSharedMemoryFile = IntPtr.Zero;

IntPtr m_pwData = IntPtr.Zero;

bool m_bAlreadyExist = false;

bool m_bInit = false;

long m_MemSize = 0;

public ShareMemLib()

{

}

~ShareMemLib()

{

Close();

}

//初始化内存

public int Init(string strName, long lngSize)

{

if (lngSize <= 0 || lngSize > 0x00800000) lngSize = 0x00800000;

m_MemSize = lngSize;

if (strName.Length > 0)

{

//创建内存共享体(INVALID_HANDLE_VALUE)

m_hSharedMemoryFile = CreateFileMapping(INVALID_HANDLE_VALUE, IntPtr.Zero, (uint)PAGE_READWRITE, 0, (uint)lngSize, strName);

if (m_hSharedMemoryFile == IntPtr.Zero)

{

m_bAlreadyExist = false;

m_bInit = false;

return 2; //创建共享体失败

}

else

{

if (GetLastError() == ERROR_ALREADY_EXISTS)  //已经创建

{

m_bAlreadyExist = true;

}

else

{

m_bAlreadyExist = false;

}

}

//创建内存映射

m_pwData = MapViewOfFile(m_hSharedMemoryFile, FILE_MAP_WRITE, 0, 0, (uint)lngSize);

if (m_pwData == IntPtr.Zero)

{

m_bInit = false;

CloseHandle(m_hSharedMemoryFile);

return 3; //创建内存映射失败

}

else

{

m_bInit = true;

if (m_bAlreadyExist == false)

{

}

}

}

else

{

return 1;

}

return 0;

}

//关闭共享内存

public void Close()

{

if (m_bInit)

{

UnmapViewOfFile(m_pwData);

CloseHandle(m_hSharedMemoryFile);

}

}

///读数据

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

{

if (lngAddr + lngSize > m_MemSize) return 2; //超出数据区

if (m_bInit)

{

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

}

else

{

return 1;

}

return 0;

}

//将数据写入共享内存中

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

{

if (lngAddr + lngSize > m_MemSize) return 2; //超出数据区

if (m_bInit)

{

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

}

else

{

return 1;

}

return 0;

}

｝

调用方法：

声明   ShareMemery.ShareMemLib MemDB = new ShareMemLib();  为公共的变量

//用下面这句话调用上面类中的初始化共享内存的方法

if (MemDB.Init("YFMemTest", 10240) != 0)

将需要写在内存中的数据：转化成为byte[]

MemDB.Write(bytData, 0, bb.Length);   //将数据写入到共享内存中

byte[] bytData = new byte[16];
            int intRet = MemDB.Read(ref bytData, 0, 16);

以上方法是读出内存中的16个字节的内容

以上方法在VS2008中经过测试。