using System; using System.Collections.Generic; using System.Text; using System.Runtime.InteropServices;namespace ShareMemLib { public class ShareMem { [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 ShareMem() { } ~ShareMem() { Close(); } /// <summary> /// 初始化共享内存 /// </summary> /// <param name="strName">共享内存名称</param> /// <param name="lngSize">共享内存大小</param> /// <returns></returns> 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 //新创建 { 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) { //初始化 } } //---------------------------------------- } else { return 1; //参数错误 } return 0; //创建成功 } /// <summary> /// 关闭共享内存 /// </summary> public void Close() { if (m_bInit) { UnmapViewOfFile(m_pwData); CloseHandle(m_hSharedMemoryFile); } } /// <summary> /// 读数据 /// </summary> /// <param name="bytData">数据</param> /// <param name="lngAddr">起始地址</param> /// <param name="lngSize">个数</param> /// <returns></returns> 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; //共享内存未初始化 } return 0; //读成功 } /// <summary> /// 写数据 /// </summary> /// <param name="bytData">数据</param> /// <param name="lngAddr">起始地址</param> /// <param name="lngSize">个数</param> /// <returns></returns> 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; //共享内存未初始化 } return 0; //写成功 } } }
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;namespace ShareMemLib
{
public class ShareMem
{
[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 ShareMem()
{
}
~ShareMem()
{
Close();
} /// <summary>
/// 初始化共享内存
/// </summary>
/// <param name="strName">共享内存名称</param>
/// <param name="lngSize">共享内存大小</param>
/// <returns></returns>
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 //新创建
{
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)
{
//初始化
}
}
//----------------------------------------
}
else
{
return 1; //参数错误
} return 0; //创建成功
}
/// <summary>
/// 关闭共享内存
/// </summary>
public void Close()
{
if (m_bInit)
{
UnmapViewOfFile(m_pwData);
CloseHandle(m_hSharedMemoryFile);
}
} /// <summary>
/// 读数据
/// </summary>
/// <param name="bytData">数据</param>
/// <param name="lngAddr">起始地址</param>
/// <param name="lngSize">个数</param>
/// <returns></returns>
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; //共享内存未初始化
}
return 0; //读成功
} /// <summary>
/// 写数据
/// </summary>
/// <param name="bytData">数据</param>
/// <param name="lngAddr">起始地址</param>
/// <param name="lngSize">个数</param>
/// <returns></returns>
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; //共享内存未初始化
}
return 0; //写成功
}
}
}
MemDB.Init("Test", 10240);//不同程序用一个共享内存 ,名字要一样
MemDB.Write(data[], 0, data.length);
CreateFileMapping
MapViewOfFile
WriteFile
API会不会帮我后台自动保存?
你要是保存成文件的话
直接用FileStrem保存内存中的数据就可以了。
MemDB.Read(data[],0,data.lenth);
FileStream.Writer(data,0,data.lenth);
MemDB.Read(data[],0,data.lenth);
FileStream.Writer(data,0,data.lenth);
将内存中的数据保存到文件中了。我的意思是在使用前面那些API创建内存映射文件的时候,
是否有某个参数可以指定我在操作文件的时候,另外有个后台线程在帮我把内存中的数据自动保存到文件中?
就像Microsoft Word软件中的自动保存一样。
MemDB.Read(data[],0,data.lenth);
FileStream.Writer(data,0,data.lenth);
将内存中的数据保存到文件中了。 我的意思是在使用前面那些API创建内存映射文件的时候,
是否有某个参数可以指定我在操作文件的时候,另外有个后台线程在帮我把内存中的数据自动保存到文件中?
就像Microsoft Word软件中的自动保存一样。
是否此时已经自动加载到内存中了?如果此时硬盘文件中的数据没有自动加载到内存共享体中,是否需要打开硬盘文件,将文件中的内容读入内存共享体中?谢谢!