原文 C#共享内存类改进版
改进说明及源码实例下载见：http://blog.****.net/zzh8845/archive/2008/11/22/3349963.aspx
ShareMem.cs
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using System.Threading;
using System.IO;
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;
IntPtr m_pwDataWrite = IntPtr.Zero;
IntPtr m_pwDataRead = IntPtr.Zero;
bool m_bAlreadyExist = false;
bool m_bInit = false;
long m_MemSize = 0;
int m_length = 0;
int m_count = 0;
const int infoSize = 50;
Semaphore semRead;
Semaphore semWrite;
Semaphore semWriteLength;
String m_pathMSGCSV = "Messages.csv";
public ShareMem()
{
}
~ShareMem()
{
Close();
}
///
/// 初始化共享内存
///
/// 共享内存名称
/// 共享内存大小
///
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 (GetLastError() == ERROR_ALREADY_EXISTS) //已经创建
{
m_bAlreadyExist = true;
m_hSharedMemoryFile = OpenFileMapping(FILE_MAP_ALL_ACCESS, false, 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_ALL_ACCESS, 0, 0, (uint)lngSize);
m_pwDataWrite = m_pwData;
m_pwDataRead = (IntPtr)(m_pwData.GetHashCode() + infoSize);
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
}
SetSemaphore();
if (m_bAlreadyExist == false)
{
WriteLengthAndCount(0, 0);
}
return 0; //创建成功
}
///
/// 关闭共享内存
///
public void Close()
{
if (m_bInit)
{
UnmapViewOfFile(m_pwData);
CloseHandle(m_hSharedMemoryFile);
}
}
public bool SetSemaphore()
{
try
{
semRead = Semaphore.OpenExisting("ReadShareMemory");
semWrite = Semaphore.OpenExisting("WriteShareMemory");
semWriteLength = Semaphore.OpenExisting("WriteLengthShareMemory");
}
catch (Exception)
{
semRead = new Semaphore(0, 1, "ReadShareMemory");
semWrite = new Semaphore(1, 1, "WriteShareMemory");
semWriteLength = new Semaphore(1, 1, "WriteLengthShareMemory");
}
return true;
}
/**
public int ReadLength()
{
Byte[] bytData = new Byte[infoSize];
if (infoSize > m_MemSize) return 2; //超出数据区
if (m_bInit)
{
Marshal.Copy(m_pwData, bytData, 0, infoSize);
}
else
{
return 1; //共享内存未初始化
}
String str = System.Text.Encoding.Unicode.GetString(bytData).Trim('/0');
m_length = System.Convert.ToInt32(str);
return 0; //读成功
}
public int WriteLength(int length)
{
semWriteLength.WaitOne();
if (infoSize > m_MemSize) return 2; //超出数据区
String strLength = System.Convert.ToString(length);
Byte[] bytData = System.Text.Encoding.Unicode.GetBytes(strLength);
if (m_bInit)
{
Marshal.Copy(bytData, 0, m_pwData, bytData.Length);
}
else
{
semWriteLength.Release();
return 1; //共享内存未初始化
}
semWriteLength.Release();
return 0;
}
**/
public int ReadLengthAndCount()
{
Byte[] bytData = new Byte[infoSize];
if (infoSize > m_MemSize) return 2; //超出数据区
if (m_bInit)
{
Marshal.Copy(m_pwData, bytData, 0, infoSize);
}
else
{
return 1; //共享内存未初始化
}
String str = System.Text.Encoding.Unicode.GetString(bytData).Trim('/0');
String[] strs = System.Text.RegularExpressions.Regex.Split(str, "/0");
m_length = System.Convert.ToInt32(strs[0]);
m_count = System.Convert.ToInt32(strs[1]);
return 0; //读成功
}
public int WriteLengthAndCount(int length, int count)
{
semWriteLength.WaitOne();
if (infoSize > m_MemSize) return 2; //超出数据区
String strLengthAndCount = System.Convert.ToString(length) + "/0" + System.Convert.ToString(count);
Byte[] bytData = System.Text.Encoding.Unicode.GetBytes(strLengthAndCount);
if (m_bInit)
{
/**
Byte[] byteZero = new Byte[infoSize];
for (int i = 0; i < infoSize; i++)
{
byteZero[i] = (Byte)'/0';
}
Marshal.Copy(byteZero, 0, m_pwData, infoSize);
* **/
Marshal.Copy(bytData, 0, m_pwData, bytData.Length);
}
else
{
semWriteLength.Release();
return 1; //共享内存未初始化
}
semWriteLength.Release();
return 0;
}
///
/// 读数据
///
/// 数据
/// 起始地址
/// 个数
///
public int Read(ref byte[] bytData)
{
ReadLengthAndCount();
if (m_length > m_MemSize) return 2; //超出数据区
if (m_bInit)
{
Marshal.Copy(m_pwDataRead, bytData, 0, m_length);
}
else
{
return 1; //共享内存未初始化
}
return 0; //读成功
}
///
/// 写数据
///
/// 数据
/// 起始地址
/// 个数
///
public int Write(byte[] bytData, int lngSize)
{
semWrite.WaitOne();
ReadLengthAndCount();
if (m_length + lngSize > m_MemSize)
{
System.Windows.Forms.MessageBox.Show("Share memory is full. " + (m_length + lngSize) + ">" + m_MemSize);
semWrite.Release();
return 2; //超出数据区
}
if (m_bInit)
{
m_pwDataWrite = (IntPtr)(m_pwData.GetHashCode() + m_length + infoSize);
Marshal.Copy(bytData, 0, m_pwDataWrite, lngSize);
m_length += lngSize;
m_count++;
}
else
{
semWrite.Release();
return 1; //共享内存未初始化
}
WriteLengthAndCount(m_length, m_count);
semWrite.Release();
return 0; //写成功
}
public int GetLength()
{
ReadLengthAndCount();
return this.m_length;
}
public int GetCount()
{
ReadLengthAndCount();
return this.m_count;
}
public int ReadCSV()
{
try
{
if (!File.Exists(m_pathMSGCSV))
File.CreateText(m_pathMSGCSV).Close();
StreamReader sr = System.IO.File.OpenText(m_pathMSGCSV);
while (!sr.EndOfStream)
{
String strLine = sr.ReadLine();
if (!System.String.IsNullOrEmpty(strLine))
{
strLine += "/0";
Byte[] data = System.Text.Encoding.Unicode.GetBytes(strLine);
Write(data, data.Length);
}
}
sr.Close();
}
catch (Exception e)
{
System.Windows.Forms.MessageBox.Show("Error:ReadCSV()" + e);
return 1;
}
return 0;
}
public int WriteCSV()
{
try
{
StreamWriter sw = System.IO.File.AppendText(m_pathMSGCSV);
ReadLengthAndCount();
Byte[] btydata = new Byte[m_length];
Read(ref btydata);
String strOut = System.Text.Encoding.Unicode.GetString(btydata).Trim('/0');
String[] sArray = System.Text.RegularExpressions.Regex.Split(strOut, "/0");
foreach (String str in sArray)
{
if (!String.IsNullOrEmpty(str))
sw.WriteLine(str);
}
sw.Flush();
sw.Close();
}
catch (Exception)
{
System.Windows.Forms.MessageBox.Show("Error:WriteCSV()");
return 1;
}
return 0;
}
public int Clear()
{
ReadLengthAndCount();
if (infoSize + m_length > m_MemSize) return 2; //超出数据区
if (m_bInit)
{
Byte[] byteZero = new Byte[infoSize + m_length];
for (int i = 0; i < infoSize; i++)
{
byteZero[i] = (Byte)'/0';
}
Marshal.Copy(byteZero, 0, m_pwData, infoSize + m_length);
m_pwDataWrite = m_pwData;
m_length = 0;
m_count = 0;
WriteLengthAndCount(0, 0);
}
return 0;
}
}
}
Form1.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using ShareMemLib;
namespace ShareMemory
{
public partial class frmMain : Form
{
ShareMem MemDB = new ShareMem();
const int m_memSize = 4096000;
public frmMain()
{
InitializeComponent();
btnInit.Enabled = true;
btnWrite.Enabled = false;
btnRead.Enabled = false;
txtInput.Text = "AAA";
}
private void ReadTest()
{
String str = ReadToStr();
String[] strArray = System.Text.RegularExpressions.Regex.Split(str, "/0");
lstData.Items.Clear();
foreach (String s in strArray)
{
lstData.Items.Add(s);
}
}
private String ReadToStr()
{
int currentLength = MemDB.GetLength();
int currentCount = MemDB.GetCount();
Byte[] data = new Byte[currentLength];
MemDB.Read(ref data);
lblUsedSize.Text = currentLength.ToString();
lblCount.Text = currentCount.ToString();
return System.Text.Encoding.Unicode.GetString(data);
}
private void WriteStr(String str)
{
btnWrite.Enabled = false;
try
{
Byte[] data = System.Text.Encoding.Unicode.GetBytes(str);
MemDB.Write(data, data.Length);
}
catch (Exception)
{
MessageBox.Show("Error in WriteStr");
}
btnWrite.Enabled = true;
}
private void btnInit_Click(object sender, EventArgs e)
{
if (MemDB.Init("YFMemTest", m_memSize) != 0)
{
//初始化失败
MessageBox.Show("初始化失败");
}
else
{
btnInit.Enabled = false;
btnWrite.Enabled = true;
btnRead.Enabled = true;
}
lblTotalSize.Text = m_memSize.ToString();
}
private void btnClear_Click(object sender, EventArgs e)
{
MemDB.Clear();
ReadTest();
}
private void btnReadCSV_Click(object sender, EventArgs e)
{
MemDB.ReadCSV();
ReadTest();
}
private void btnWriteCSV_Click(object sender, EventArgs e)
{
MemDB.WriteCSV();
MemDB.Clear();
ReadTest();
}
private void btnRead_Click(object sender, EventArgs e)
{
ReadTest();
}
private void btnWrite_Click(object sender, EventArgs e)
{
//String str = "B000" + (i++) + ",1,1,2008,success/0";
String str = txtInput.Text + System.DateTime.Now.ToString(",yyyMMdd,HHmmss,fff/0");
WriteStr(str);
ReadTest();
}
}
}