C#共享内存类改进版

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.csdn.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();
        }
    }
}