UDP send /recieve problem... well mainly recieve - C# Discussion Boards

convert to an array? send it and then convert it back to a list? Any way to just access the list in form1 from form2?

Kendall

I have this method:

public static List<PartModel> QueryInventoryParts(List<<SearchItemModel>> SearchTerms, int ProducId = 0)
{
    using (SparesDataContext context = getDataContext())
    {
        List<<PartModel>> retVal = new List<<PartModel>>();

        foreach (SearchItemModel searchModel in SearchTerms)
        { 
            List<<PartModel>> results = (from pp in context.mmlProductsParts
                                        join pa in context.tblParts on pp.PartId equals pa.PartId
                                        where pa.PartNumber.Contains(searchModel.SearchTerm) ||
                                                pa.Keyword.Contains(searchModel.SearchTerm)
                                        select new PartModel
                                        {
                                            PartId = pa.PartId,
                                            Category = GetCategory(pa.CategoryId),
                                            PartNumber = pa.PartNumber,
                                            Keywords = pa.Keyword,
                                            PartDescription = pa.Description,
                                            Price = pa.Price.Value,
                                            Ratio = pa.Ratio.Value,
                                            Tribal = pa.Tribal
                                        }).ToList();

            foreach (var result in results)
            {
                retVal.Add(result);
            }
        }
        return retVal;
    }
}

If the ProductId is passed in, then I was to add "&& pp.ProductId = ProductId" to the WHERE clause,
however, if Zero is passed in, I want to return all products.

I'm not sure of the syntax on this. Can someone show me?

Thanks

Everything makes sense in someone's mind

where (...) && ((pp.ProductId == ProductId) || (ProductId == 0))

Or am I missing something?

Hi, probably not the best solution but off the top of my head i can think of 2 methods.

1. Use a switch on ProductID - case 0: --> do query to return all
default: --> do other query to return specifics matching ProductId

2.

List<< PartModel>>  results = ((ProductId != 0) ?  (from pp in context.mmlProductsParts
                                       join pa in context.tblParts on pp.PartId equals pa.PartId
                                       where pa.PartNumber.Contains(searchModel.SearchTerm) ||
                                               pa.Keyword.Contains(searchModel.SearchTerm)
                                               && pp.ProductId == ProductId
                                       select new PartModel
                                       {
                                           PartId = pa.PartId,
                                           Category = GetCategory(pa.CategoryId),
                                           PartNumber = pa.PartNumber,
                                           Keywords = pa.Keyword,
                                           PartDescription = pa.Description,
                                           Price = pa.Price.Value,
                                           Ratio = pa.Ratio.Value,
                                           Tribal = pa.Tribal
                                       }).ToList()
                                       : (from pp in context.mmlProductsParts
                                       join pa in context.tblParts on pp.PartId equals pa.PartId
                                       where pa.PartNumber.Contains(searchModel.SearchTerm) ||
                                               pa.Keyword.Contains(searchModel.SearchTerm)
                                        select new PartModel
                                        {
                                           PartId = pa.PartId,
                                           Category = GetCategory(pa.CategoryId),
                                           PartNumber = pa.PartNumber,
                                           Keywords = pa.Keyword,
                                           PartDescription = pa.Description,
                                           Price = pa.Price.Value,
                                           Ratio = pa.Ratio.Value,
                                           Tribal = pa.Tribal
                                       }).ToList());

Hope that helps

What's the right way to do this:

var temp = (from pr in context.tblProducts
                join pp in context.mmlProductsParts on pr.ProductId equals pp.ProductId
                join pa in context.tblParts on pp.PartId equals pa.PartId
                where pr.ProductSeries.Contains(searchModel.SearchTerm) ||
                        pr.ProductNumber.Contains(searchModel.SearchTerm)
                select new ProductModel
                {
                    ProductId = pr.ProductId,
                    ProductNumber = pr.ProductNumber,
                    ProductSeries = pr.ProductSeries,
                    Parts = (new PartModel
                            {
                                PartId = pa.PartId,
                                Category = GetCategory(pa.CategoryId),
                                PartNumber = pa.PartNumber,
                                Keywords = pa.Keyword,
                                PartDescription = pa.Description,
                                Price = pa.Price.Value,
                                Ratio = pa.Ratio.Value,
                                Tribal = pa.Tribal
                            }).ToList())
                }).ToList();

The property Parts on the Product model is of type List<partmodel>. The compiler is complaining telling me that PartModel does not contain a definition fo "ToList".

What's the right way to do this??

Everything makes sense in someone's mind

While I can't understand the depths of this code, I think I can ask an obvious question:

If 'Parts is a list, I assume a generic list of 'PartModel, then why, when you create a new 'PartModel, and assign values to its inner fields, are you not adding it to the 'Parts list ?

"I have always wished for my computer to be as easy to use as my telephone; my wish has come true because I can no longer figure out how to use my telephone." Bjarne Stroustrop circa 1990

Hi - I just converted an ASP.Net web app from 2.0 to 4.0 and the XslTransform code that I inherited no longer works in 4.0. I'm told I need to change the code to use XslCompiledTransform. Fine - but I can't figure out how to get XslCompiledTransform to do exactly what I need it to do. I have an XSL file in my project. I do not have an XML or HTML file. The old code read as follows:

C#

using (DataSet data = DataGateway.getAbsence(TripNum)) 
{ 
  data.DataSetName = "Absence"; 
  data.Tables[0].TableName = "Employee"; 
  XmlDataDocument xmldoc = new XmlDataDocument(Data); 
  XslTransform xslt = new XslTransform; 
  string xsltfile = "myfile.xsl"; 
  xslt.Load(xsltfile); 
  TextWriter writer = new StringWriter(); 
  xslt.Transform(xmldoc, null, writer, null); 
  MailMessage mail = new MailMessage(); 
  mail.Body = writer.ToString(); 
  mail.From = "me"; 
  mail.To = "you"; 
  //more code to send mail...... 
}

I've tried to rewrite this by substituting and XsltCompiledTransform object for the XslTransform object, and an XmlWriter object for the TextWriter object, but the xslt.Transform line complains about my using an XmlDataDocument as input. It suggests an XmlReader instead, but I don't know how to pass the data from my DataSet into an XmlReader. Or perhaps XslCompiledTransform is not the way to go Does anyone know?

Thanks!

Give me the codezzzzzzzzz Poke tongue | ;-P

No no seriously now I have a piece of code that joins a group, sends data and awaits response.
I fore up Whireshark and see the data I send, I see the data that is being send back but I never get the data in my code.

Here is the code with

C#

UDPClient

(which I copied from MS) and I also have code which I made with sockets and both behave the same way so I stick with the

UDPClient

one

C#

    // This constructor arbitrarily assigns the local port number.
    UdpClient udpClient = new UdpClient("224.0.1.1", 3333);
    try
    {
  //      udpClient.Connect("224.0.1.1", 3333);

        // Sends a message to the host to which you have connected.

        MemoryStream ms = new MemoryStream();
        BinaryWriter bw = new BinaryWriter(ms);

        Int32 b = 0x01;
        bw.Write(b); //MsgOpCode = 0x01
        string str = "FF:FF:FF:FF:FF:FF";
        bw.Write(Encoding.ASCII.GetBytes(str.ToCharArray()));//mac
        bw.Write('\0');//-ip
        bw.Write('\0');//-mask

        byte[] byteArray = ms.GetBuffer();

        udpClient.Send(byteArray, byteArray.Length);

        // Sends a message to a different host using optional hostname and port parameters.

        //IPEndPoint object will allow us to read datagrams sent from any source.
        IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);

        // Blocks until a message returns on this socket from a remote host.
        Byte[] receiveBytes = udpClient.Receive(ref RemoteIpEndPoint);
        string returnData = Encoding.ASCII.GetString(receiveBytes);

        // Uses the IPEndPoint object to determine which of these two hosts responded.
        Console.WriteLine("This is the message you received " +
                                     returnData.ToString());
        Console.WriteLine("This message was sent from " +
                                    RemoteIpEndPoint.Address.ToString() +
                                    " on their port number " +
                                    RemoteIpEndPoint.Port.ToString());

        udpClient.Close();
    }
    catch (Exception e)
    {
        Console.WriteLine(e.ToString());
    }
}

Any insights on why I am not getting the data I requested (although I see it in wireshark?)

In case you ask I have been at it all day Sniff | :^)

Alberto Bar-Noy
---------------
“The city’s central computer told you? R2D2, you know better than to trust a strange computer!”
(C3PO)

Do you by any chance have one or more firewalls blockting UDP port 3333?

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Firewalls off. Unsure | :~

Alberto Bar-Noy
---------------
“The city’s central computer told you? R2D2, you know better than to trust a strange computer!”
(C3PO)

Alberto Bar-Noy wrote:
why I am not getting the data

Please describe the expected and actual behavior properly. Is your program hanging? throwing an exception? returning an empty string? or what?

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

It just blocks on the receive for ever while the other side transmits data on a loop for ever (with a 30 second sleep in between)

Alberto Bar-Noy
---------------
“The city’s central computer told you? R2D2, you know better than to trust a strange computer!”
(C3PO)

Hmm. Looks ok to me. Can you see what port the return messages are being sent to on WireShark?

Regards,
Rob Philpott.

Given I use IPAddress.Any and 0 in the endpoint does it matter?

Alberto Bar-Noy
---------------
“The city’s central computer told you? R2D2, you know better than to trust a strange computer!”
(C3PO)

They get set on the way out so I don't think that actually has any effect.

My only hunch is that the return message isn't coming back on port 3333. Here's an alternative bit of code I used to to DNS queries using UDP. You could try this instead:

C#

Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, 1000);
socket.SendTo(requestMessage, requestMessage.Length, SocketFlags.None, server); // requestMessage is a byte[], server is an IPEndPoint
byte[] responseMessage = new byte[512];
socket.Receive(responseMessage);

Regards,
Rob Philpott.

Have you tried googling udpclient receive not working? It offers a number of hints...

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Oh yes before I cme to the board. This was the first thing to do. Tried the hints, the codes the whatnots

Alberto Bar-Noy
---------------
“The city’s central computer told you? R2D2, you know better than to trust a strange computer!”
(C3PO)

Bloody hell bloody Microsoft.

I made RT app developer (and I tried form another PC as well not only from RT device) send me a response not from where he got my message to his 3333 port but back to my 3334 port and WHAM it worked Mad | :mad:

So why give the any port option to begin with!!!! Mad | :mad:

Thanks for the help guys!

Alberto Bar-Noy
---------------
“The city’s central computer told you? R2D2, you know better than to trust a strange computer!”
(C3PO)

Hi All,

I have a winform application connected with a sql server 2005/2008 database. Now i have about 200 stored procedures which i would like to distribute with the application and execute as soon as the user creates a new datbase.

i do not want to make use of the specific dll like sqldmo and sqlserver.management, etc.. I want it to have it as clean as possible.

Below the function i use for testing ( forget the fixed file path Smile | :)

). Creating datbase and tables are no problem. However creation of the storedprocedure returns errors.

************** Exception Text **************
System.Data.SqlClient.SqlException (0x80131904): Incorrect syntax near the keyword 'TO'.
Incorrect syntax near the keyword 'TO'.
Incorrect syntax near '0'.
   at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)
   at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
   at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning()
   at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
   at System.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean async)
   at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe)
   at System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
   at AgentBase.Business.clsDataModel.fncCreateNewDatabase(String DBNAME, String FILELOCATION) in C:\AgentBase.2010\AgentBase.Business\clsDataModel.cs:line 91
   at AgentBase.Gui.usxConnections.butCreateDB_Click(Object sender, EventArgs e) in C:\AgentBase.2010\AgentBase.Gui\usxConnections.cs:line 293
   at System.Windows.Forms.Control.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ButtonBase.WndProc(Message& m)
   at System.Windows.Forms.Button.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Any suggestions, tips, tricks.

C#

using System;
using System.IO;
using System.Data.SqlClient;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using AgentBase.Datalayer;
public static void fncCreateNewDatabase(string DBNAME, string FILELOCATION )
		{
		
			SqlConnection myConn = new SqlConnection(Globals.ConnectionString);		  

			string str = "CREATE DATABASE " + DBNAME + " ON PRIMARY " +
				"(NAME = " + DBNAME + "_Data, " +
				"FILENAME = '" + FILELOCATION + "\\DATA\\" + DBNAME + "_Data.mdf', " +
				"SIZE = 10MB, MAXSIZE = 10000MB, FILEGROWTH = 10%) " +
				"LOG ON (NAME = " + DBNAME + "_Log, " +
				"FILENAME = '" + FILELOCATION + "\\DATA\\" + DBNAME + "_Log.ldf', " +
				"SIZE = 5MB, " +
				"MAXSIZE = 50000MB, " +
				"FILEGROWTH = 10%)";

            string myServer = myConn.DataSource.ToString();

            SqlCommand myCommand = new SqlCommand(str, myConn);
			myConn.Open();
			myCommand.ExecuteNonQuery();
           
            myConn.Close();
            myConn = new SqlConnection("Server=" + myServer + ";Integrated security=SSPI;database=" + DBNAME + "");
            myConn.Open();
            SqlCommand cmd = new SqlCommand();
            //SqlDataReader reader;
            string sourceDir = "C:\\AgentBase.2010\\AgentBase\\bin\\Debug\\database\\";
            string[] fileEntries = Directory.GetFiles(sourceDir);
            foreach (string fileName in fileEntries)
            {

                // do something with fileName
                //FileInfo file = new FileInfo("C:\\AgentBase.2010\\AgentBase\\bin\\Debug\\database\\CreateDBStructure.sql");
                FileInfo file = new FileInfo(fileName.ToString());
                string script = file.OpenText().ReadToEnd();

                cmd.CommandText = script;
                //cmd.CommandType = System.Data.CommandType.Text;            //cmd.CommandType = cmd.CommandType.Text;
                cmd.Connection = myConn;
                cmd.ExecuteNonQuery();
			
            }
"

SQL

IF exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[sptblPersonGetAll]') and OBJECTPROPERTY(id, N'IsProcedure') = 1)
BEGIN
   PRINT 'Dropping procedure sptblPersonGetAll ...'
   DROP PROCEDURE [dbo].[sptblPersonGetAll]
END
GO
PRINT 'Creating procedure sptblPersonGetAll ...'
GO


CREATE PROCEDURE [dbo].[sptblPersonGetAll]
(@PE_ID int
,@PE_RE_ID bigint
,@PE_TYPE bigint
,@PE_LASTNAME nvarchar(50)
,@PE_FIRSTNAME nvarchar(50)
,@PE_INITIALS nvarchar(50)
,@PE_CONFIRMATIONS bit
,@PE_INVOICES bit
,@PE_NEWORDER bit
)
AS
/* *********************************************************************************
**   Database:    REZON4V9
**   Project:     REZON4V9
**
**   Name:        [sptblPersonGetAll]
**   Decription:  Gets all the records in the '[tblPerson]' that match
**                the specified critieria. 
**
**   Remarks:     Any parameters passed as NULL will not affect the records returned.
**                They will effectively be ignored in the WHERE clause.
**
**   Called From: daltblPerson 
**
************************************************************************************
**                     CHANGE HISTORY
**  Change No:   Date:          Author:   Description:
**  _________    ___________    ______    ______________________________________
**     001       2/4/2011     V        Created.                                
**
** ****************************************************************************** */

SET NOCOUNT ON
SET XACT_ABORT OFF -- Allow procedure to continue after error

DECLARE @ProcName    varchar(30)       -- Name of this procedure
DECLARE @Error       integer           -- Local variable to capture the error code.
DECLARE @RowCnt      integer           -- Number of rows returned 
DECLARE @ErrMsg      nvarchar(1000)    -- Error message to return
DECLARE @Parameters  nvarchar(4000)    -- String representing parameters



-- *******************
-- Set local variables
-- *******************
SELECT @ProcName  = object_name(@@procid)
     , @Error     = 0
     , @RowCnt    = 0



-- *****************************************
-- Parameter string. Used for error handling
-- *****************************************
SET @Parameters = '' 
                + ' PE_ID:' + COALESCE(CONVERT(VARCHAR, @PE_ID), 'NULL')
                + ' PE_RE_ID:' + COALESCE(CONVERT(VARCHAR, @PE_RE_ID), 'NULL')
                + ' PE_TYPE:' + COALESCE(CONVERT(VARCHAR, @PE_TYPE), 'NULL')
                + ' PE_LASTNAME:' + COALESCE(CONVERT(VARCHAR, @PE_LASTNAME), 'NULL')
                + ' PE_FIRSTNAME:' + COALESCE(CONVERT(VARCHAR, @PE_FIRSTNAME), 'NULL')
                + ' PE_INITIALS:' + COALESCE(CONVERT(VARCHAR, @PE_INITIALS), 'NULL')
                + ' PE_CONFIRMATIONS:' + COALESCE(CONVERT(VARCHAR, @PE_CONFIRMATIONS), 'NULL')
                + ' PE_INVOICES:' + COALESCE(CONVERT(VARCHAR, @PE_INVOICES), 'NULL')
                + ' PE_NEWORDER:' + COALESCE(CONVERT(VARCHAR, @PE_NEWORDER), 'NULL')



-- ************
-- Get the data
-- ************
SELECT [PE_ID]
      ,[PE_RE_ID]
      ,[PE_TYPE]
      ,[PE_LASTNAME]
      ,[PE_FIRSTNAME]
      ,[PE_INITIALS]
      ,[PE_SEX]
      ,[PE_FUNCTION]
      ,[PE_PHONE]
      ,[PE_FAX]
      ,[PE_MOBILE]
      ,[PE_WEBSITE]
      ,[PE_EMAIL]
      ,[PE_SKYPE]
      ,[PE_LINKEDIN]
      ,[PE_FACEBOOK]
      ,[PE_BIRTHDAY]
      ,[PE_MEMO]
      ,[IS_DATECREATED]
      ,[IS_WHO]
      ,[IS_DATECHANGED]
      ,[PE_CONFIRMATIONS]
      ,[PE_INVOICES]
      ,[PE_NEWORDER]
      ,[PE_CONTACTFOR]
      ,[PE_SPEAKSLANGUAGE]
  FROM [dbo].[tblPerson]
 WHERE (([PE_ID] = @PE_ID) OR (@PE_ID IS NULL))
   AND (([PE_RE_ID] = @PE_RE_ID) OR (@PE_RE_ID IS NULL))
   AND (([PE_TYPE] = @PE_TYPE) OR (@PE_TYPE IS NULL))
   AND (([PE_LASTNAME] LIKE @PE_LASTNAME + '%') OR (@PE_LASTNAME IS NULL))
   AND (([PE_FIRSTNAME] = @PE_FIRSTNAME) OR (@PE_FIRSTNAME IS NULL))
   AND (([PE_INITIALS] = @PE_INITIALS) OR (@PE_INITIALS IS NULL))
   AND (([PE_CONFIRMATIONS] = @PE_CONFIRMATIONS) OR (@PE_CONFIRMATIONS IS NULL))
   AND (([PE_INVOICES] = @PE_INVOICES) OR (@PE_INVOICES IS NULL))
   AND (([PE_NEWORDER] = @PE_NEWORDER) OR (@PE_NEWORDER IS NULL))

SELECT @Error  = @@Error
     , @RowCnt = @@RowCount 
IF (@Error != 0)
BEGIN
   SELECT @ErrMsg = 'Error getting records. Parameters' + @Parameters
   GOTO ENDERROR
END



-- **************
-- Error Handling
-- **************
GOTO ENDOK

ENDERROR:
   BEGIN
      EXEC spErrorLogInsert 'DB Layer', @ProcName, @Error, @ErrMsg
      RAISERROR 25000 @ErrMsg
      RETURN 1
   END

ENDOK:
   RETURN 0
GO



IF ( object_id('dbo.sptblPersonGetAll') IS NOT NULL )
BEGIN
   PRINT 'Success: Created procedure sptblPersonGetAll.'
END
IF ( object_id('dbo.sptblPersonGetAll') IS NULL )
BEGIN
   PRINT 'ERROR: sptblPersonGetAll was not created successfully.'
END
GO

Kind regards,

Marcel Vreuls

AgentBase

<<A good idea can change your life>>

How about using the sql command utility. See this http://www.sqlservercentral.com/Forums/Topic572280-8-1.aspx[^]

Hi All,

I have an image on which I'm drawing elements ("masks") using a Graphics object (g.DrawCurve, g.FillRectangle, g.DrawPolygon etc.).

Now, when hovering with the mouse over the image, I need to know whether I'm hovering over a mask (a part that was drawn using the Graphics object).

I couldn't find a way to get a Graphic's drawing pixels... any ideas?

Thanks!

One thing you could do is this:
- have a bitmap ("bm") the same size as the object you are drawing on, then get its graphics ("gbm") and fill with a white backcolor;
- mimic all your drawing on gbm too, using any color but white;
- when you need to know whether a point (x,y) is mask or not, look at bm.GetPixel(x,y) and the color will tell you.

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Hi Guys,

Just a quick question I have c# code working for communicating with a Serial device using the SerialPort Class (see code below):

private void SendEnq(bool blnIncStep)
     {
         if (blnIncStep)
         {
             iStep++;
         }

         byte[] c = new byte[]
         {
             0x05,
         };

         spBPDione.Write(c, 0, c.Length);
         Console.WriteLine("OUT:  " + ByteToHex(c));

     }

     private void DataRecvEvent()
     {
         int bytes = spBPDione.BytesToRead;

         byte[] comBuffer = new byte[bytes];

         spBPDione.Read(comBuffer, 0, bytes);

         Console.WriteLine("IN:  " + ByteToHex(comBuffer));
         Console.WriteLine("STEP:" + iStep);

         if (ByteToHex(comBuffer).Trim() == "06")
         {
             if (iStep >= 2)
             {
                 //All good to here
             }
             else
             {
                 byte[] c = new byte[] {
                    0x02, 0x31, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x31, 0x30, 0x31, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x31,
                    0x30, 0x30, 0x30, 0x30, 0x31, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x31, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
                    0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x31, 0x20, 0x20, 0x20,
                    0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x03,
                    0x02 /*LRC*/
                 };

                 spBPDione.Write(c, 0, c.Length);
                 Console.WriteLine("OUT:  " + ByteToHex(c));
                 iStep++;
             }
         }
         else if (ByteToHex(comBuffer).Trim() == "07")
         {
             byte[] c = new byte[] {
                0x04,
             };

             spBPDione.Write(c, 0, c.Length);
             Console.WriteLine("OUT:  " + ByteToHex(c));
             iStep++;
         }
         else if (ByteToHex(comBuffer).Trim() == "05")
         {
             if (iStep >= 2)
             {
                 byte[] c = new byte[] {
                     0x06,
                 };

                 //spBPDione.ReceivedBytesThreshold = 29;

                 spBPDione.Write(c, 0, c.Length);
                 Console.WriteLine("OUT:  " + ByteToHex(c));
             }
         }
         else if (ByteToHex(comBuffer).Trim().StartsWith("02"))
         {
             if (iStep >= 2)
             {
                 byte[] c = new byte[] {
                     0x07,
                 };

                 spBPDione.Write(c, 0, c.Length);
                 Console.WriteLine("OUT:  " + ByteToHex(c));
             }
         }
         else if (ByteToHex(comBuffer).Trim() == "04")
         {
             if (iStep >= 2)
             {
                 byte[] c = new byte[] {
                     0x06,
                 };

                 spBPDione.Write(c, 0, c.Length);
                 Console.WriteLine("OUT:  " + ByteToHex(c));
             }
         }
     }

Now this works and will do what its supposed to on the device it is not very nice clean maintainable code, could i refactor this into a class that follows the following protocol to make the code more readable and OO.

My System      			DIRECTION    	 Physical Device
ENQ (05)             	        ->            
	           		<-		 ACK0 (06)
STX (message) ETX LRC		->
				<-		 ACK1 (07)
EOT (04)			->
				<-		 ACK0 (06)
				<-		 ENQ (05)
ACK0 (06)			->
				<-		 STX (message) ETX LRC
ACK1 (07)			->
				<-		EOT (04)
ACK0 (06) 			->

There are many ways to implement a comm protocol, the best one very much depends on the requirements on reliability, robustness and performance. Here are two extremes:

1.
A very easy approach would do everything in a synchronous way, which means NOT using events (e.g. DataReceived); e.g. have a separate thread that basically does what your protocol diagram shows, including some explicit delays:

Write ENQ
Wait 100
Read 1 and check for ACK0
Write STX msg ETX LRC
Wait 100
Read 1 and check for ACK1
...

The waits are necessary if you want a good chance of getting the next input all in one read(buf); if you read too early, you might get a partial message.

Warning: You have to decide what should happen when something unexpected is read!

2.
The general approach would be completely asynchronous, and it would use a state machine, so the DataReceived handler would consist of a big switch on the state variable, and a number of cases each handling one input line of your protocol diagram. Here too you must make sure your diagram is complete, i.e. in each state what should happen if arbitrary stuff is received?

And then you should also take care of time-outs: what when no data at all, or an insufficient amount of data, is received? Your app probably doesn't want to wait forever...

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Thanks Luc.

Is the If / Else block in my code not already doing what you talk about with the State Machine pattern?