.NET进程通信机制——内存映像文件

 对win32api的封装

using  System;
using  System.Runtime.InteropServices;

namespace  WindowsApplication1
... {
    internal class Win32
    ...{ 
        public static readonly IntPtr InvalidHandleValue = new IntPtr(-1);
        public const UInt32 FILE_MAP_WRITE = 2;
        public const UInt32 PAGE_READWRITE = 0x04;

        [DllImport("Kernel32")]
        public static extern IntPtr CreateFileMapping(IntPtr hFile,
            IntPtr pAttributes, UInt32 flProtect,
            UInt32 dwMaximumSizeHigh, UInt32 dwMaximumSizeLow, String pName);

        [DllImport("Kernel32")]
        public static extern IntPtr MapViewOfFile(IntPtr hFileMappingObject,
            UInt32 dwDesiredAccess,
            UInt32 dwFileOffsetHigh, UInt32 dwFileOffsetLow,
            IntPtr dwNumberOfBytesToMap);

        [DllImport("Kernel32")]
        public static extern Boolean UnmapViewOfFile(IntPtr address);
    
    }
}

测试用的winform设计界面

写入内存映射文件的代码

private   void  Write_Click( object  sender, System.EventArgs e)
         ... {
            IntPtr hFileMap = IntPtr.Zero;
            IntPtr address;

            hFileMap = Win32.CreateFileMapping(Win32.InvalidHandleValue,
                IntPtr.Zero, Win32.PAGE_READWRITE,
                0, 0x100, "MYSHARE");

            
            if (hFileMap == IntPtr.Zero)
                throw new Exception("CreateFileMapping()：无法创建内存映像文件");

            address = Win32.MapViewOfFile(hFileMap, Win32.FILE_MAP_WRITE,
                0, 0, IntPtr.Zero);

            byte[] bs = System.Text.Encoding.GetEncoding("gb2312").GetBytes(this.textBox1.Text);

            for(int i=0;i<bs.Length;i++)
            ...{
                Marshal.WriteByte(address,i,bs[i]);
            }
            Marshal.WriteByte(address,bs.Length,0);


            Win32.UnmapViewOfFile(address);

        }

从内存映射文件读出的代码

private   void  Read_Click( object  sender, System.EventArgs e)
         ... {
            IntPtr hFileMap = IntPtr.Zero;
            IntPtr address;

            hFileMap = Win32.CreateFileMapping(Win32.InvalidHandleValue,
                IntPtr.Zero, Win32.PAGE_READWRITE,
                0, 0x100, "MYSHARE");

            if (hFileMap == IntPtr.Zero)
                throw new Exception("CreateFileMapping()：无法创建内存映像文件");

            address = Win32.MapViewOfFile(hFileMap, Win32.FILE_MAP_WRITE,
                0, 0, IntPtr.Zero);

            byte[] bs = new byte[0x100];
            int i;
            for(i=0;i<bs.Length;i++)
            ...{
                byte temp = Marshal.ReadByte(address,i);
                if(temp==0)
                    break;
                bs[i] = temp;
            
            }

            Win32.UnmapViewOfFile(address);

            this.textBox2.Text = System.Text.Encoding.GetEncoding("gb2312").GetString(bs,0,i);

        }

测试结果截图