Named pipes between Delphi win32 and C#

It helps if you show you're code. Are you sure that you are using the same name for the pipes. Maybe a ansi / unicode string problem (dot net is always unicode, older delphi versions always ansi)

Please tell more about what works and doesn';t work. Can they 'open' each others pipes? Or is the actually sending of data a problem?

Hi! I get an error from windows but the fatal one "xxx has stopped working...Check online, close, debug"
I can connect, and the server is invoked, but the length of the message is always zero.
When I press OK on the showDialog("com") the Delphi exe crashes out to windows.

The code is just copy an paste from the above to links, but here is what I test with.

Client.cs:

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using Microsoft.Win32.SafeHandles;
using System.Threading;
using System.IO;

namespace PipeClient
{
    class Client
    {
        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern SafeFileHandle CreateFile(
          String pipeName,
          uint dwDesiredAccess,
          uint dwShareMode,
          IntPtr lpSecurityAttributes,
          uint dwCreationDisposition,
          uint dwFlagsAndAttributes,
          IntPtr hTemplate);

        public const uint GENERIC_READ = (0x80000000);
        public const uint GENERIC_WRITE = (0x40000000);
        public const uint OPEN_EXISTING = 3;
        public const uint FILE_FLAG_OVERLAPPED = (0x40000000);

        public delegate void MessageReceivedHandler(string message);
        public event MessageReceivedHandler MessageReceived;

        public const int BUFFER_SIZE = 4096;

        string pipeName;
        private FileStream stream;
        private SafeFileHandle handle;
        Thread readThread;
        bool connected;

        public bool Connected
        {
            get { return this.connected; }
        }

        public string PipeName
        {
            get { return this.pipeName; }
            set { this.pipeName = value; }
        }

        /// <summary>
        /// Connects to the server
        /// </summary>
        public void Connect()
        {
            this.handle =
              CreateFile(
                  this.pipeName,
                  GENERIC_READ | GENERIC_WRITE,
                  0,
                  IntPtr.Zero,
                  OPEN_EXISTING,
                  FILE_FLAG_OVERLAPPED,
                  IntPtr.Zero);

            //could not create handle - server probably not running
            if (this.handle.IsInvalid)
                return;

            this.connected = true;

            //start listening for messages
            this.readThread = new Thread(new ThreadStart(Read));
            this.readThread.Start();
        }

        /// <summary>
        /// Reads data from the server
        /// </summary>
        public void Read()
        {
            this.stream = new FileStream(this.handle, FileAccess.ReadWrite, BUFFER_SIZE, true);
            byte[] readBuffer = new byte[BUFFER_SIZE];
            ASCIIEncoding encoder = new ASCIIEncoding();
            while (true)
            {
                int bytesRead = 0;

                try
                {
                    bytesRead = this.stream.Read(readBuffer, 0, BUFFER_SIZE);
                }
                catch
                {
                    //read error occurred
                    break;
                }

                //server has disconnected
                if (bytesRead == 0)
                    break;

                //fire message received event
                if (this.MessageReceived != null)
                    this.MessageReceived(encoder.GetString(readBuffer, 0, bytesRead));
            }

           

            //clean up resource
            this.stream.Close();
            this.handle.Close();
        }

        /// <summary>
        /// Sends a message to the server
        /// </summary>
        /// <param name="message"></param>
        public void SendMessage(string message)
        {
            ASCIIEncoding encoder = new ASCIIEncoding();
            byte[] messageBuffer = encoder.GetBytes(message);

            this.stream.Write(messageBuffer, 0, messageBuffer.Length);
            this.stream.Flush();
        }
    }
}


Form1.cs:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace PipeClient
{
    public partial class Form1 : Form
    {
        private Client pipeClient;

        public Form1()
        {
            InitializeComponent();
            this.pipeClient = new Client();
            this.pipeClient.MessageReceived +=
                new Client.MessageReceivedHandler(pipeClient_MessageReceived);
        }

        void pipeClient_MessageReceived(string message)
        {
            this.Invoke(new Client.MessageReceivedHandler(DisplayReceivedMessage),
                new object[] { message });
        }

        void DisplayReceivedMessage(string message)
        {
            this.tbReceived.Text += message + "\r\n";
        }

        private void btnStart_Click(object sender, EventArgs e)
        {
            if (!this.pipeClient.Connected)
            {
                this.pipeClient.PipeName = this.tbPipeName.Text;
                this.pipeClient.Connect();
                this.btnStart.Enabled = false;
            }
            else
                MessageBox.Show("Already connected.");
        }

        private void btnSend_Click(object sender, EventArgs e)
        {
            this.pipeClient.SendMessage(this.tbSend.Text);
        }
    }
}


formNamedPipes_server

unit formNamedPipe_server;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

const
  cShutDownMsg = 'shutdown pipe ';
  cPipeFormat = '\\%s\pipe\%s';

type
  RPIPEMessage = record
    Size: DWORD;
    Kind: Byte;
    Count: DWORD;
    Data: array[0..8095] of Char;
  end;

  TPipeServer = class(TThread)
  private
    FHandle: THandle;
    FPipeName: String;

  protected
  public
    constructor CreatePipeServer(aServer, aPipe: String; StartServer: Boolean);
    destructor Destroy; override;

    procedure StartUpServer;
    procedure ShutDownServer;
    procedure Execute; override;
  end;


type
  TfrmNamedPipe_server = class(TForm)
    Memo1: TMemo;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  frmNamedPipe_server: TfrmNamedPipe_server;

implementation

{$R *.dfm}

var
    FServer:    TPipeServer;


procedure CalcMsgSize(var Msg: RPIPEMessage);
begin
  Msg.Size :=
    SizeOf(Msg.Size) +
    SizeOf(Msg.Kind) +
    SizeOf(Msg.Count) +
    Msg.Count +
    3;
end;

{ TPipeServer }

constructor TPipeServer.CreatePipeServer(
  aServer, aPipe: String; StartServer: Boolean
);
begin
  if aServer = '' then
    FPipeName := Format(cPipeFormat, ['.', aPipe])
  else
    FPipeName := Format(cPipeFormat, [aServer, aPipe]);
  // clear server handle
  FHandle := INVALID_HANDLE_VALUE;
  if StartServer then
    StartUpServer;
  // create the class
  Create(not StartServer);
end;

destructor TPipeServer.Destroy;
begin
  if FHandle <> INVALID_HANDLE_VALUE then
    // must shut down the server first
    ShutDownServer;
  inherited Destroy;
end;

procedure TPipeServer.Execute;
var
  I, Written: Cardinal;
  InMsg, OutMsg: RPIPEMessage;
begin
  while not Terminated do
  begin
    if FHandle = INVALID_HANDLE_VALUE then
    begin
      // suspend thread for 250 milliseconds and try again
      Sleep(250);
    end else begin
      if ConnectNamedPipe(FHandle, nil) then
      try
        // read data from pipe
        InMsg.Size := SizeOf(InMsg);
        ReadFile(FHandle, InMsg, InMsg.Size, InMsg.Size, nil);
        if
          (InMsg.Kind = 0) and
          (StrPas(InMsg.Data) = cShutDownMsg + FPipeName)
        then
        begin
          // process shut down
          OutMsg.Kind := 0;
          OutMsg.Count := 3;
          OutMsg.Data := 'OK'#0;
          Terminate;
        end else begin
            // data send to pipe should be processed here
          OutMsg := InMsg;
          frmNamedPipe_server.Memo1.Lines.Add('Command: '+{StrPas(InMsg.Data)+}' length: '+intToStr(InMsg.Count));
          // we'll just reverse the data sent, byte-by-byte
          for I := 0 to Pred(InMsg.Count) do
            OutMsg.Data[Pred(InMsg.Count) - I] := InMsg.Data[I];
        end;
showmessage('COM');
        CalcMsgSize(OutMsg);
        WriteFile(FHandle, OutMsg, OutMsg.Size, Written, nil);
        frmNamedPipe_server.Memo1.Lines.Add('Result: '+StrPas(OutMsg.Data));
      finally
        DisconnectNamedPipe(FHandle);
      end;
    end;
  end;
end;

procedure TPipeServer.ShutDownServer;
var
  BytesRead: Cardinal;
  OutMsg, InMsg: RPIPEMessage;
  ShutDownMsg: String;
begin
  if FHandle <> INVALID_HANDLE_VALUE then
  begin
    // server still has pipe opened
    OutMsg.Size := SizeOf(OutMsg);
    // prepare shut down message
    with InMsg do
    begin
      Kind := 0;
      ShutDownMsg := cShutDownMsg + FPipeName;
      Count := Succ(Length(ShutDownMsg));
      StrPCopy(Data, ShutDownMsg);
    end;
    CalcMsgSize(InMsg);
    // send shut down message
    CallNamedPipe(
      PChar(FPipeName), @InMsg, InMsg.Size, @OutMsg, OutMsg.Size, BytesRead, 100
    );
    // close pipe on server
    CloseHandle(FHandle);
    // clear handle
    FHandle := INVALID_HANDLE_VALUE;
  end;
end;

procedure TPipeServer.StartUpServer;
begin
  // check whether pipe does exist
  if WaitNamedPipe(PChar(FPipeName), 100 {ms}) then
    raise Exception.Create('Requested PIPE exists already.');
  // create the pipe
  FHandle := CreateNamedPipe(
    PChar(FPipeName), PIPE_ACCESS_DUPLEX,
    {PIPE_TYPE_MESSAGE or PIPE_READMODE_MESSAGE or PIPE_WAIT} 0,
    PIPE_UNLIMITED_INSTANCES, SizeOf(RPIPEMessage), SizeOf(RPIPEMessage),
    NMPWAIT_USE_DEFAULT_WAIT, nil
  );
  // check if pipe was created
  if FHandle = INVALID_HANDLE_VALUE then
    raise Exception.Create('Could not create PIPE.');
end;


procedure TfrmNamedPipe_server.FormCreate(Sender: TObject);
begin
    try
        FServer:=TPipeServer.CreatePipeServer('', 'testpipe', True);
    except
        on E: Exception do begin
            ShowMessage(E.Message);
        end;
    end
end;

end.

I found a new example and I got it to work, I think that FILE_FLAG_OVERLAPPED mainly did the thrick.
Thx for showing interrest MvanderKooij.

BTW: I will (try to) use the right zone next time.

Great that you got it working, can be real pain...