建站
咨詢
售后
建站咨詢
新聞中心
這里有您想知道的互聯(lián)網(wǎng)營銷解決方案
C#共享內(nèi)存操作類實例淺析
C#共享內(nèi)存操作是如何實現(xiàn)的呢？VC++的共享內(nèi)存操作代碼實現(xiàn)起來相對比較容易，但是用C#語言來實現(xiàn)，就有一定難度，由于工作需要，把以前VC開發(fā)的共享內(nèi)存代碼要用C#實現(xiàn)，別說，還費了不少周折，畢竟C#操作API函數(shù)和地址指針不是那么直接，還好，總算完成了，效果還不錯。
C#共享內(nèi)存操作類實例：
- 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﹥
- /// 初始化共享內(nèi)存
- /// ﹤/summary﹥
- /// ﹤param name="strName"﹥共享內(nèi)存名稱﹤/param﹥
- /// ﹤param name="lngSize"﹥共享內(nèi)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)
- {
- //創(chuàng)建內(nèi)存共享體(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; //創(chuàng)建共享體失敗
- }
- else
- {
- if (GetLastError() == ERROR_ALREADY_EXISTS) //已經(jīng)創(chuàng)建
- {
- m_bAlreadyExist = true;
- }
- else //新創(chuàng)建
- {
- m_bAlreadyExist = false;
- }
- }
- //---------------------------------------
- //創(chuàng)建內(nèi)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; //創(chuàng)建內(nèi)存映射失敗
- }
- else
- {
- m_bInit = true;
- if (m_bAlreadyExist == false)
- {
- //初始化
- }
- }
- //----------------------------------------
- }
- else
- {
- return 1; //參數(shù)錯誤
- }
- return 0; //創(chuàng)建成功
- }
- /// ﹤summary﹥
- /// 關(guān)閉共享內(nèi)存
- /// ﹤/summary﹥
- public void Close()
- {
- if (m_bInit)
- {
- UnmapViewOfFile(m_pwData);
- CloseHandle(m_hSharedMemoryFile);
- }
- }
- /// ﹤summary﹥
- /// 讀數(shù)據(jù)
- /// ﹤/summary﹥
- /// ﹤param name="bytData"﹥數(shù)據(jù)﹤/param﹥
- /// ﹤param name="lngAddr"﹥起始地址﹤/param﹥
- /// ﹤param name="lngSize"﹥個數(shù)﹤/param﹥
- /// ﹤returns﹥﹤/returns﹥
- public int Read(ref byte[] bytData,
- int lngAddr, int lngSize)
- {
- if (lngAddr + lngSize ﹥ m_MemSize) return 2;
- //超出數(shù)據(jù)區(qū)
- if (m_bInit)
- {
- Marshal.Copy(m_pwData, bytData, lngAddr, lngSize);
- }
- else
- {
- return 1; //共享內(nèi)存未初始化
- }
- return 0; //讀成功
- }
- /// ﹤summary﹥
- /// 寫數(shù)據(jù)
- /// ﹤/summary﹥
- /// ﹤param name="bytData"﹥數(shù)據(jù)﹤/param﹥
- /// ﹤param name="lngAddr"﹥起始地址﹤/param﹥
- /// ﹤param name="lngSize"﹥個數(shù)﹤/param﹥
- /// ﹤returns﹥﹤/returns﹥
- public int Write(byte[] bytData, int lngAddr, int lngSize)
- {
- if (lngAddr + lngSize ﹥ m_MemSize) return 2; //超出數(shù)據(jù)區(qū)
- if (m_bInit)
- {
- Marshal.Copy(bytData, lngAddr, m_pwData, lngSize);
- }
- else
- {
- return 1; //共享內(nèi)存未初始化
- }
- return 0; //寫成功
- }
- }
- }
C#共享內(nèi)存操作類實例測試例程：
- using System;
- using System.Collections.Generic;
- using System.ComponentModel;
- using System.Data;
- using System.Drawing;
- using System.Text;
- using System.Windows.Forms;
- using ShareMemLib;
- namespace YFShareMem
- {
- public partial class frmShareMem : Form
- {
- ShareMem MemDB=new ShareMem();
- public frmShareMem()
- {
- InitializeComponent();
- }
- private void btnOpen_Click(object sender, EventArgs e)
- {
- if (MemDB.Init("YFMemTest", 10240) != 0)
- {
- //初始化失敗
- MessageBox.Show("初始化失敗");
- }
- else
- {
- btnOpen.Enabled = false;
- chkWrite.Enabled = true;
- tmrTime.Enabled = true;
- }
- }
- private void tmrTime_Tick(object sender, EventArgs e)
- {
- byte[] bytData = new byte[16];
- int intRet = MemDB.Read(ref bytData, 0, 16);
- lstData.Items.Clear();
- if (intRet == 0)
- {
- for (int i = 0; i ﹤ 16; i++)
- {
- lstData.Items.Add(bytData[i].ToString());
- }
- if (chkWrite.Checked)
- {
- bytData[0]++;
- bytData[1] += 2;
- if (bytData[0] ﹥ 200) bytData[0] = 0;
- if (bytData[1] ﹥ 200) bytData[1] = 0;
- MemDB.Write(bytData, 0, 16);
- }
- }
- }
- }
- }
C#共享內(nèi)存操作類的基本內(nèi)容就向你介紹到這里，希望對你了解和學(xué)習(xí)C#共享內(nèi)存操作類有所幫助。
【編輯推薦】
- C#操作文本文件應(yīng)用實例簡析
- C#操作文本文件演練實例淺析
- C#操作內(nèi)存之指針淺析
- C#操作內(nèi)存讀寫方法淺析
- C#操作內(nèi)存實例詳解
新聞標題：C#共享內(nèi)存操作類實例淺析
鏈接分享：http://www.dlmjj.cn/article/cdpcdhi.html
