.NET进程通信机制——邮槽

 win32api包装

using System;
using System.Runtime.InteropServices;

namespace WindowsApplication2
...{
    /**//// <summary>
    /// Win32 的摘要说明。
    /// </summary>
    internal class Win32
    ...{
        public static readonly IntPtr MAILSLOT_WAIT_FOREVER = new IntPtr(-1);
        public static readonly IntPtr INVALID_HANDLE_VALUE = new IntPtr(-1);

        [DllImport("kernel32.dll")]
        public static extern IntPtr CreateMailslot(string lpName, uint nMaxMessageSize,
            IntPtr lReadTimeout, IntPtr lpSecurityAttributes);

        [DllImport("kernel32.dll", SetLastError=true, CharSet=CharSet.Auto)]
        public static extern IntPtr CreateFile(
            string lpFileName,
            EFileAccess dwDesiredAccess,
            EFileShare dwShareMode,
            IntPtr lpSecurityAttributes,
            ECreationDisposition dwCreationDisposition,
            EFileAttributes dwFlagsAndAttributes,
            IntPtr hTemplateFile);

        [DllImport("kernel32.dll")]
        public static extern bool ReadFile(IntPtr hFile, byte[] lpBuffer,
            uint nNumberOfBytesToRead, out uint lpNumberOfBytesRead, IntPtr lpOverlapped);

        [DllImport("kernel32.dll")]
        static extern bool WriteFile(IntPtr hFile, byte [] lpBuffer,
            uint nNumberOfBytesToWrite, out uint lpNumberOfBytesWritten,
            [In] ref System.Threading.NativeOverlapped lpOverlapped);

        [Flags]
            public enum EFileAccess : uint
        ...{
            GenericRead = 0x80000000,
            GenericWrite = 0x40000000,
            GenericExecute = 0x20000000,
            GenericAll = 0x10000000
        }

        [Flags]
            public enum EFileShare : uint
        ...{
            None = 0x00000000,
            Read = 0x00000001,
            Write = 0x00000002,
            Delete = 0x00000004
        }

        public enum ECreationDisposition : uint
        ...{
            New = 1,
            CreateAlways = 2,
            OpenExisting = 3,
            OpenAlways = 4,
            TruncateExisting = 5
        }

        [Flags]
            public enum EFileAttributes : uint
        ...{
            Readonly         = 0x00000001,
            Hidden           = 0x00000002,
            System           = 0x00000004,
            Directory        = 0x00000010,
            Archive          = 0x00000020,
            Device           = 0x00000040,
            Normal           = 0x00000080,
            Temporary        = 0x00000100,
            SparseFile       = 0x00000200,
            ReparsePoint     = 0x00000400,
            Compressed       = 0x00000800,
            Offline          = 0x00001000,
            NotContentIndexed= 0x00002000,
            Encrypted        = 0x00004000,
            Write_Through    = 0x80000000,
            Overlapped       = 0x40000000,
            NoBuffering      = 0x20000000,
            RandomAccess     = 0x10000000,
            SequentialScan   = 0x08000000,
            DeleteOnClose    = 0x04000000,
            BackupSemantics  = 0x02000000,
            PosixSemantics   = 0x01000000,
            OpenReparsePoint = 0x00200000,
            OpenNoRecall     = 0x00100000,
            FirstPipeInstance= 0x00080000
        }
    }
}

服务器设计界面

服务器端代码

private IntPtr mailslot;
        private Thread t_ReadingProc = null;
        private void button1_Click_1(object sender, System.EventArgs e)
        ...{
            this.mailslot = Win32.CreateMailslot("//./Mailslot/Myslot",0,Win32.MAILSLOT_WAIT_FOREVER,new IntPtr(0));
            if(this.mailslot == Win32.INVALID_HANDLE_VALUE)
            ...{
                this.textBox1.Text = "创建邮槽失败";
            }
            else
            ...{
                this.textBox1.Text += System.DateTime.Now.ToLongTimeString()+"成功创建邮槽//./Mailslot/Myslot ";
                t_ReadingProc= new Thread(new ThreadStart(Reading));
                t_ReadingProc.Start();
                this.textBox1.Text += System.DateTime.Now.ToLongTimeString()+"启动读邮槽线程 ";
            }
            
        }

        private void Reading()
        ...{
            byte[] buffer = new byte[256];
            uint bn = 0;
            while(Win32.ReadFile(this.mailslot,buffer,256,out bn,new IntPtr(0)))
            ...{
                this.textBox1.Text += System.DateTime.Now.ToLongTimeString()+"邮槽接收到如下数据："+System.Text.Encoding.GetEncoding("gb2312").GetString(buffer,0,Convert.ToInt32(bn))+" ";
            }
        }

客户端设计界面

客户端代码

        private IntPtr mailslot;
        private void button2_Click(object sender, System.EventArgs e)
        ...{
            this.mailslot = Win32.CreateFile(
                "//./Mailslot/Myslot",
                Win32.EFileAccess.GenericWrite,
                Win32.EFileShare.Read,
                new IntPtr(0),
                Win32.ECreationDisposition.OpenExisting,
                Win32.EFileAttributes.Normal,
                new IntPtr(0));
            if(this.mailslot==Win32.INVALID_HANDLE_VALUE)
            ...{
                MessageBox.Show("连接邮槽失败");
            }
            else
            ...{
                this.button2.Text = "已连接";
                this.button2.Enabled = false;
                this.button1.Enabled = true;
            }
        }
        private void button1_Click(object sender, System.EventArgs e)
        ...{
            
                byte[] b = System.Text.Encoding.GetEncoding("gb2312").GetBytes(this.textBox1.Text);
                uint bl;
                
                System.Threading.NativeOverlapped lp = new System.Threading.NativeOverlapped();
                
                if(Win32.WriteFile(
                    this.mailslot,b,Convert.ToUInt16(b.Length),out bl,ref lp))
                ...{
                    //MessageBox.Show("发送成功");
                }
                else
                ...{
                    MessageBox.Show("发送失败");
                }

        }

测试结果截图