Re: Packet issues - C# Discussion Boards

Re: How can we remove specific node in the XML file by LINQ?

20-Jun-08 8:05

To be honest I have never used XLINQ, but your example looks ok (I really just being pedantic about your subject question Poke tongue | ;-P

).

I just had a look at it, and I cannot see why you code should not work.

If I do see why, I will let you know Smile | :)

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IronScheme - 1.0 alpha 4a out now (29 May 2008)

Mohammad Dayyan20-Jun-08 9:09

Mohammad Dayyan

20-Jun-08 9:09

All right.

Sorry for my English. I'm a freshman .

Re: How can we remove specific node in the XML file by LINQ?

Mohammad Dayyan20-Jun-08 9:13

Mohammad Dayyan

20-Jun-08 9:13

Who can help me ?

Sorry for my English. I'm a freshman .

Packet issues

see_seA20-Jun-08 5:15

20-Jun-08 5:15

I've highly modified the code found here http://www.codeproject.com/KB/IP/ChatAsynchTCPSockets.aspx.

When creating a packet, I give the following class the info it needs onto which is converts it into a byte[] and visa versa which can then be sent and received by a socket respectively.

public class Data
{
    //Default constructor
    public Command cmdCommand; //Command type (login, logout, send message, etcetera)
    public string strMessage; //Message text
    public string strName; //Name by which the client logs into the room

    public Data()
    {
        cmdCommand = Command.Null;
        strMessage = null;
        strName = null;
    }

    //Converts the bytes into an object of type Data
    public Data(byte[] data)
    {
        //The first four bytes are for the Command
        cmdCommand = (Command)BitConverter.ToInt32(data, 0);

        //The next four store the length of the name
        int nameLen = BitConverter.ToInt32(data, 4);

        //The next four store the length of the message
        int msgLen = BitConverter.ToInt32(data, 8);

        //This check makes sure that strName has been passed in the array of bytes
        if (nameLen > 0)
            strName = Encoding.UTF8.GetString(data, 12, nameLen);
        else
            strName = null;

        //This checks for a null message field
        if (msgLen > 0)
            strMessage = Encoding.UTF8.GetString(data, 12 + nameLen, msgLen);
        else
            strMessage = null;
    }

    //Converts the Data structure into an array of bytes
    public byte[] ToByte()
    {
        List<byte> result = new List<byte>();

        //First four are for the Command
        result.AddRange(BitConverter.GetBytes((int)cmdCommand));

        //Add the length of the name
        if (strName != null)
            result.AddRange(BitConverter.GetBytes(strName.Length));
        else
            result.AddRange(BitConverter.GetBytes(0));

        //Length of the message
        if (strMessage != null)
            result.AddRange(BitConverter.GetBytes(Encoding.UTF8.GetByteCount(strMessage)));
        else
            result.AddRange(BitConverter.GetBytes(0));

        //Add the name
        if (strName != null)
            result.AddRange(Encoding.UTF8.GetBytes(strName));

        //And, lastly we add the message text to our array of bytes
        if (strMessage != null)
            result.AddRange(Encoding.UTF8.GetBytes(strMessage));

        return result.ToArray();
    }
}</byte></byte>

However on some occasions of high traffic I get the following error:

Index and count must refer to a location within the buffer.
Parameter name: bytes
A first chance exception of type 'System.ArgumentOutOfRangeException' occurred in mscorlib.dll

I feel the constructor which takes a byte array is the cause here. Can anyone suggest a better way of sending this data or point out the problem in the code which I cannot see? Sniff | :^)

Help would be greatly appreciated.

leppie20-Jun-08 5:34

20-Jun-08 5:34

Please fix the generics in the post. I am pretty sure that is a List of byte.

xacc.ide - now with TabsToSpaces support
IronScheme - 1.0 alpha 4a out now (29 May 2008)

leppie20-Jun-08 5:37

20-Jun-08 5:37

At which point do you get this error?

I suspect, the byte[] you pass to the constructor does not contain the correct data.

Add a check in the beginning of the constructor to ensure the byte[] is long enough at least.

xacc.ide - now with TabsToSpaces support
IronScheme - 1.0 alpha 4a out now (29 May 2008)

see_seA20-Jun-08 5:52

20-Jun-08 5:52

As far as I can tell, I get the error after executing the following commands:

In the OnAccept method..

byte[] bufData = new byte[1024];
clientSocket.BeginReceive(bufData, 0, bufData.Length, SocketFlags.None, new AsyncCallback(OnReceive),
                          new object[] {clientSocket, bufData});

In the OnReceive method..

Socket clientSocket = null;
            Data msgReceived = null;
            byte[] bufData = new byte[1024];
            bool bypass = false;
            ClientInfo cInfo = null;

            try
            {
                bool blInvalidClient = false;

                try
                {
                    object[] oData = (object[]) ar.AsyncState;
                    clientSocket = (Socket) oData[0];
                    bufData = (byte[]) oData[1];
                    clientSocket.EndReceive(ar);

                    //Console.WriteLine(clientList.Count);
                }
                catch (SocketException)
                {
                    blInvalidClient = true;
                }

                if (!blInvalidClient)
                {
                    //Transform the array of bytes received from the user into an
                    //intelligent form of object Data
                    msgReceived = Packet.PacketReceived(bufData);
...

The Packet.PacketReceived method returns new Data(bufData). I've added traces in that constructor and there is something incorrect happening. All clients that communicate use the same Data class to convert the info into a byte[] so it's not as if I'm sending an arb string of bytes to the socket.

But the weird thing is that this only ever happens when I sent lots of packets to the socket at once.

see_seA20-Jun-08 6:04

20-Jun-08 6:04

Problem seems to be here. Not sure I understand why...

if (nameLen > 0)
    strName = Encoding.UTF8.GetString(data, 12, nameLen);
else
    strName = null;

leppie20-Jun-08 7:01

20-Jun-08 7:01

It probably does not allow you to read zero strings (assuming it needs a 0 terminator).

xacc.ide - now with TabsToSpaces support
IronScheme - 1.0 alpha 4a out now (29 May 2008)

see_seA20-Jun-08 7:05

20-Jun-08 7:05

Packets are lost due to this under high load. I'm out of ideas.

see_seA20-Jun-08 7:56

Transparency On Parent Form .

20-Jun-08 7:56

Hmmm. I increased the buffer size from 1024 to 4096 and everything seems to work perfectly now.

unitecsoft20-Jun-08 4:58

unitecsoft

20-Jun-08 4:58

Hi everyone

I am trying to use the Form property TranseparencyKey on a form which is a child for a MidParent from . The result should make the selected color area transparent and so the image of the MidParent form apears .
this feature doe not work , it works only if the form is not owned by a MidParent . any Ideas ?

Thanx .

Re: Transparency On Parent Form .

see_seA20-Jun-08 5:16

inserting data SQLCommand C# - am I missing something?

20-Jun-08 5:16

Forms do weird things when you make them transparent from my experiences.

laziale20-Jun-08 4:18

Re: inserting data SQLCommand C# - am I missing something?

20-Jun-08 4:18

hi guys! I am building an app, and at one point I want to insert data in local DB, everything goes ok, connString is opening, but the data is not going in to the DB, am I missing something in the code?

string query = "INSERT INTO Orders(Order_Name, Order_Data, DateInserted, OrderStatus) VALUES ('"+ Name + "','" + Data + "','" + DateTime.Now + "','" + City + "')";
SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\App_Data\OStorage.mdf;Integrated Security=True;User Instance=True;Trusted_Connection=Yes");
conn.Open();
SqlCommand comm = new SqlCommand(query, conn);
comm.ExecuteNonQuery();

I am executing the same query with SSMSE, and it is working without any problem, so I really don't know where I am making a mistake. Thanks ahead for any help

User 665820-Jun-08 4:25

Re: inserting data SQLCommand C# - am I missing something?

20-Jun-08 4:25

How many rows affected does ExecuteNonQuery() return? Do you use a SqlTransaction[^] to Commit the changes to the database?

regards

modified 12-Sep-18 21:01pm.

laziale20-Jun-08 4:32

Re: inserting data SQLCommand C# - am I missing something?

20-Jun-08 4:32

It is affecting one row each time the query is executed

User 665820-Jun-08 4:36

Re: inserting data SQLCommand C# - am I missing something?

20-Jun-08 4:36

So do you commit the insert using the SqlTransaction.Commit method?

modified 12-Sep-18 21:01pm.

laziale20-Jun-08 4:39

Re: inserting data SQLCommand C# - am I missing something?

20-Jun-08 4:39

no, how should I do that? I haven't used that method at all for now, can you pls give me some help how should i use it? Thx

User 665820-Jun-08 4:39

Re: inserting data SQLCommand C# - am I missing something?

20-Jun-08 4:39

I posted a link to MSDN in my orignal post, there's an example how to use transactions:

http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqltransaction(VS.80).aspx[^]

modified 12-Sep-18 21:01pm.

laziale20-Jun-08 4:43

Re: inserting data SQLCommand C# - am I missing something?

20-Jun-08 4:43

thx, I will check it out now...

laziale20-Jun-08 5:01

Re: inserting data SQLCommand C# - am I missing something?

20-Jun-08 5:01

I use it the informations what you provide me, and it gives me error after the ExecuteNonQuery line, here is how I tried to solve:

SqlTransaction transaction;
transaction = conn.BeginTransaction("BeginTransaction");
SqlCommand command = conn.CreateCommand();
try
{

command.CommandText = query;
command.ExecuteNonQuery();
transaction.Commit();
}
catch (Exception ex)
{
throw new Exception(ex.ToString(), ex);
}
finally
{
conn.Close();
}

This is the exception:
System.InvalidOperationException: ExecuteNonQuery requires the command to have a transaction when the connection assigned to the command is in a pending local transaction. The Transaction property of the command has not been initialized.

User 665820-Jun-08 5:11

Re: inserting data SQLCommand C# - am I missing something?

20-Jun-08 5:11

You forgot to insert command.Transaction = transaction before executing the query.

modified 12-Sep-18 21:01pm.

leppie20-Jun-08 4:29

Re: inserting data SQLCommand C# - am I missing something?

20-Jun-08 4:29

So do you get an error?

Are you attaching the correct database file when you look for the data?

xacc.ide - now with TabsToSpaces support
IronScheme - 1.0 alpha 4a out now (29 May 2008)

laziale20-Jun-08 4:31