using System; using System.Collections.Generic; using System.Text; using System.Runtime.InteropServices; using System.IO; using System.Data.SqlClient; namespace WinApp { public class Sequence { [DllImport("kernel32.dll")] public static extern IntPtr CreateFileMapping(IntPtr hFile,IntPtr lpFileMappingAttributes, uint flProtect,uint dwMaximumSizeHigh, uint dwMaximumSizeLow, string lpName); [DllImport("kernel32.dll")] public static extern IntPtr MapViewOfFile(IntPtr hFileMappingObject, uint dwDesiredAccess, uint dwFileOffsetHigh, uint dwFileOffsetLow, IntPtr dwNumberOfBytesToMap); [DllImport("kernel32.dll")] public static extern bool UnmapViewOfFile(IntPtr lpBaseAddress); [DllImport("kernel32.dll")] public static extern bool CloseHandle(IntPtr hObject); [DllImport("kernel32.dll")] public static extern IntPtr CreateFile(string lpFileName,int dwDesiredAccess, FileShare dwShareMode, IntPtr securityAttrs, FileMode dwCreationDisposition, int dwFlagsAndAttributes, IntPtr hTemplateFile); [DllImport("kernel32.dll")] public static extern uint GetFileSize(IntPtr hFile, IntPtr lpFileSizeHigh); public const int GENERIC_READ = -2147483648; //0x80000000 public const int GENERIC_WRITE = 0x40000000; public const int GENERIC_EXECUTE = 0x20000000; public const int GENERIC_ALL = 0x10000000; public const int FILE_ATTRIBUTE_NORMAL = 0x80; public const int FILE_FLAG_SEQUENTIAL_SCAN = 0x8000000; public const int INVALID_HANDLE_VALUE = -1; public const int PAGE_NOACCESS = 1; public const int PAGE_READONLY = 2; public const int PAGE_READWRITE = 4; public const int FILE_MAP_COPY = 1; public const int FILE_MAP_WRITE = 2; public const int FILE_MAP_READ = 4; public static string MappingFileRead() { string result = ""; try { IntPtr vFileHandle = CreateFile(@"c:/test.txt", GENERIC_READ | GENERIC_WRITE, FileShare.Read | FileShare.Write,IntPtr.Zero, FileMode.Open, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, IntPtr.Zero); if (INVALID_HANDLE_VALUE != (int)vFileHandle) { IntPtr vMappingHandle = CreateFileMapping(vFileHandle, IntPtr.Zero, PAGE_READWRITE, 0, 0, "~MappingTemp"); if (vMappingHandle != IntPtr.Zero) { IntPtr vHead = MapViewOfFile(vMappingHandle, FILE_MAP_COPY | FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, IntPtr.Zero); if (vHead != IntPtr.Zero) { uint vSize = GetFileSize(vFileHandle, IntPtr.Zero); byte[] res = new byte[vSize]; Marshal.Copy(vHead, res, 0, (int)vSize); result = ASCIIEncoding.Default.GetString(res); string[] _str = result.Split('|'); result = _str[0]; /* //*************************************** //_IntPtr = Marshal.ReadIntPtr(vHead); byte[] contentbyte1 = new byte[vSize]; for (int i = 0; i < vSize; i++) { byte vTemp = Marshal.ReadByte((IntPtr)((int)vHead + i)); contentbyte1[i] = vTemp; } Console.WriteLine(ASCIIEncoding.Default.GetString(contentbyte1));//全部值 //*************************************** byte[] contentbyte = new byte[vSize]; for (int i = 0; i < vSize; i++) { byte vTemp = Marshal.ReadByte((IntPtr)((int)vHead + i)); contentbyte[i] = vTemp; if (vTemp == '|')//設定標識結束符合 { break; } } Console.WriteLine(ASCIIEncoding.Default.GetString(contentbyte));//要取的值 result = ASCIIEncoding.Default.GetString(contentbyte); //*************************************** */ UnmapViewOfFile(vHead); } CloseHandle(vMappingHandle); } CloseHandle(vFileHandle); } } catch { } return result; } public static IntPtr InvalidHandleValue = new IntPtr(-1); public static void MappingFileWrite(string val) { try { IntPtr vFileHandle = CreateFile(@"c:/test.txt", GENERIC_READ | GENERIC_WRITE, FileShare.Read | FileShare.Write, IntPtr.Zero, FileMode.Open, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, IntPtr.Zero); if (INVALID_HANDLE_VALUE != (int)vFileHandle) { IntPtr vMappingHandle = CreateFileMapping(vFileHandle, IntPtr.Zero, PAGE_READWRITE, 0, (UInt32)(val.Length + 1), "~MappingTemp"); if (vMappingHandle != IntPtr.Zero) { IntPtr vHead = MapViewOfFile(vMappingHandle, FILE_MAP_COPY | FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, IntPtr.Zero); if (vHead != IntPtr.Zero) { byte[] by = ASCIIEncoding.Default.GetBytes(val + "|"); //設定標識結束符合 | Marshal.Copy(by, 0, vHead, by.Length); UnmapViewOfFile(vHead); } CloseHandle(vMappingHandle); } CloseHandle(vFileHandle); } } catch { } } public static void MappingWrite1(string val) { try { IntPtr vMappingHandle = CreateFileMapping(InvalidHandleValue, IntPtr.Zero, PAGE_READWRITE, 0, (UInt32)(val.Length + 1), "~MappingTemp"); if (vMappingHandle != IntPtr.Zero) { IntPtr vHead = MapViewOfFile(vMappingHandle, FILE_MAP_COPY | FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, IntPtr.Zero); if (vHead != IntPtr.Zero) { byte[] by = ASCIIEncoding.Default.GetBytes(val + "|"); //設定標識結束符合 | Marshal.Copy(by, 0, vHead, by.Length); UnmapViewOfFile(vHead); } //CloseHandle(vMappingHandle); } } catch { } } public static string MappingRead1() { string result = ""; try { IntPtr vMappingHandle = CreateFileMapping(InvalidHandleValue, IntPtr.Zero, PAGE_READWRITE, 0, 7, "~MappingTemp"); if (vMappingHandle != IntPtr.Zero) { IntPtr vHead = MapViewOfFile(vMappingHandle, FILE_MAP_COPY | FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, IntPtr.Zero); if (vHead != IntPtr.Zero) { byte[] bytData = new byte[7]; Marshal.Copy(vHead, bytData, 0, 7); result = ASCIIEncoding.Default.GetString(bytData); UnmapViewOfFile(vHead); } CloseHandle(vMappingHandle); } } catch { } return result; } } }

使用Win32 API.
大概步驟是:
1. 首先CreateFile開啟檔案獲得一個檔案的控制代碼,然後CreateFileMaping建立對映並獲得對映的控制代碼,CloseHandle關閉檔案控制代碼.
2. 對映檢視(MapViewOfFile),注意對映檢視不應該太大,採取多次進行,並獲得檢視記憶體地址,然後就可以針對這段檢視進行操作了,操作完成,使用UnMapViewOfFile來清除資源.
3. 關閉對映,使用CloseHandle關閉對映的控制代碼.