C# Socket.BeginReceive/EndReceive - C# Discussion Boards

Eddy Vluggen7-Sep-09 1:22

7-Sep-09 1:22

CSV isn't meant as a database, just as XML or Excell-files. That something is possible, doesn't mean that it's a good idea.

XML and CSV are slow if you treat them as a database, since the layout isn't optimized for that kind of access. Your best bet would be to use database, and export the pieces you need to CSV. If you're looking for something free and simple, consider SQLCE.

That being said, it is possible to read/write CSV data as if it were a database. You'll only need a connectionstring[^] Smile | :)

"Always code as if the guy who ends up maintaining your code will be a violent psychopath who knows where you live."

-- Martin Golding

Thanks a lot

Abbas_here7-Sep-09 1:37

Abbas_here

7-Sep-09 1:37

Abbas

Re: CSV file

Vivek Vijayan7-Sep-09 1:25

Vivek Vijayan

7-Sep-09 1:25

if u r new in C#, better dont use CSV for database..

This code was posted by me...

Re: CSV file

DaveyM697-Sep-09 1:35

DaveyM69

7-Sep-09 1:35

CSV can be a useful format for importing/exporting data, but although it's possible to do so, I wouldn't recommend using it as a DB.

Dave

Generic BackgroundWorker - My latest article!
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Why are you using VB6? Do you hate yourself? (Christian Graus)

Re: CSV file

Henry Minute9-Sep-09 11:40

Henry Minute

9-Sep-09 11:40

If you must use a CSV file take a look at this[^] utility.

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

Re: CSV file

Abbas_here9-Sep-09 20:30

Abbas_here

9-Sep-09 20:30

Thanks a lot

How to stream an FLV vdo on a device application

Vivek Vijayan7-Sep-09 1:00

Vivek Vijayan

7-Sep-09 1:00

I am working on a device application using Visual Studio 2005 (C#). in the application i need an option to stream vdos within the application. i tried the web browser component by giving embed code as its document text to embed an flv player. no error is shown.. but i guess compact framework is not supporting ActiveX... it just displays a blank browser.. when i tried the same embed code on an HTML page... it is working........is there any way i can do this on a device application? Frown | :(

This code was posted by me...

C# Socket.BeginReceive/EndReceive

staticv7-Sep-09 0:24

staticv

7-Sep-09 0:24

In what order is the Socket.BeginReceive/EndReceive functions called?

For instance, I call BeginReceive twice, once to get the message length and the second time to get the message itself. Now the scenario is like that, for every message I send, I start waiting for its completion (actually acknowledgment of the message sent, also I wait for the action's completion after receiving the acknowledgment), so I call BeginReceive with each BeginSend, but in each BeginReceive's callback, I check if I'm receiving the length or the message. If I'm receiving the message and have received it completely, then I call another BeginReceive to receive the completion of the action. Now this is where things get out of sync. Because one of my receive callback is receiving bytes which it interprets as the length of them message when in fact it is the message itself.

Now how do I resolve it?

Here is the code, basically it is too big, sorry for that

public void Send(string message)
        {
                try
                {
                        bytesSent = 0;

                        writeDataBuffer = System.Text.Encoding.ASCII.GetBytes(message);
                        writeDataBuffer = WrapMessage(writeDataBuffer);
                        messageSendSize = writeDataBuffer.Length;

                        clientSocket.BeginSend(writeDataBuffer, bytesSent, messageSendSize, SocketFlags.None,
                                                                new AsyncCallback(SendComplete), clientSocket);
                }
                catch (SocketException socketException)
                {
                        MessageBox.Show(socketException.Message);
                }
        }

        public void WaitForData()
        {
                try
                {
                        if (! messageLengthReceived)
                        {
                                clientSocket.BeginReceive(receiveDataBuffer, bytesReceived, MESSAGE_LENGTH_SIZE - bytesReceived,
                                                                                SocketFlags.None, new AsyncCallback(RecieveComplete), clientSocket);
                        }
        public void Send(string message)
{
    try
    {
        bytesSent = 0;

        writeDataBuffer = System.Text.Encoding.ASCII.GetBytes(message);
        writeDataBuffer = WrapMessage(writeDataBuffer);
        messageSendSize = writeDataBuffer.Length;

        clientSocket.BeginSend(writeDataBuffer, bytesSent, messageSendSize, SocketFlags.None,
                                                new AsyncCallback(SendComplete), clientSocket);
    }
    catch (SocketException socketException)
    {
        MessageBox.Show(socketException.Message);
    }
}

public void WaitForData()
{
    try
    {
        if (! messageLengthReceived)
        {
                clientSocket.BeginReceive(receiveDataBuffer, bytesReceived, MESSAGE_LENGTH_SIZE - bytesReceived,
                                                                SocketFlags.None, new AsyncCallback(RecieveComplete), clientSocket);
        }
        else 
        {
                clientSocket.BeginReceive(receiveDataBuffer, bytesReceived, messageLength - bytesReceived,
                                                                SocketFlags.None, new AsyncCallback(RecieveComplete), clientSocket);
        }
    }
    catch (SocketException socketException)
    {
        MessageBox.Show(socketException.Message);
    }
}

public void RecieveComplete(IAsyncResult result)
{
    try
    {
        Socket socket = result.AsyncState as Socket;
        bytesReceived = socket.EndReceive(result);

        if (! messageLengthReceived)
        {
                if (bytesReceived != MESSAGE_LENGTH_SIZE)
                {
                        WaitForData();
                        return;
                }

                // unwrap message length
                int length = BitConverter.ToInt32(receiveDataBuffer, 0);
                length = IPAddress.NetworkToHostOrder(length);

                messageLength = length;
                messageLengthReceived = true;

                bytesReceived = 0;

                // now wait for getting the message itself
                WaitForData();
        }
        else
        {
                if (bytesReceived != messageLength)
                {
                        WaitForData();
                }
                else
                {
                string message = Encoding.ASCII.GetString(receiveDataBuffer);

                MessageBox.Show(message);

                bytesReceived = 0;
                messageLengthReceived = false;

                // clear buffer
                receiveDataBuffer = new byte[AsyncClient.BUFFER_SIZE];

                WaitForData();
                }
        }
    }
    catch (SocketException socketException)
    {
        MessageBox.Show(socketException.Message);
    }

}

public void SendComplete(IAsyncResult result)
{
    try
    {
        Socket socket = result.AsyncState as Socket;
        bytesSent = socket.EndSend(result);

        if (bytesSent != messageSendSize)
        {
                messageSendSize -= bytesSent;

                socket.BeginSend(writeDataBuffer, bytesSent, messageSendSize, SocketFlags.None,
                                                new AsyncCallback(SendComplete), clientSocket);
                return;
        }

        // wait for data
        messageLengthReceived = false;
        bytesReceived = 0;

        WaitForData();
    }
    catch (SocketException socketException)
    {
        MessageBox.Show(socketException.Message);
    }
}

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Re: C# Socket.BeginReceive/EndReceive

Luc Pattyn7-Sep-09 2:31

Luc Pattyn

7-Sep-09 2:31

Hi,

According to the documentation, each BeginXxx needs a corresponding EndXxx, and typically that can be handled by the callback method.

I can't tell you what exactly is wrong in your code, however it is my impression your code is too complex and not sufficiently safe. I would code this more defensively, and avoid all the global variables your class seems to hold (receiveDataBuffer, bytesReceived, messageLengthReceived).

These are things I would do differently:

1.
I would create a little class holding clientSocket, the receive data buffer, an index into it;
then create two instances (one for length, one for data) of it for each length+data communication, and pass them as the last parameter to the BeginReceive calls (and retrieve it from the EndReceive calls).

2.
I would completely split the WaitForData() method into a WaitForLength method and a WaitForData method.
And I would completely split the RecieveComplete() method into a ReceivedLength method and a ReceivedData method.

(2) makes messageLengthReceived redundant.
(1) avoids the risk of receiveDataBuffer and bytesReceived to contain data belonging to another ongoing communication.

I am not saying the problem will be solved by doing this, I do claim the code would be more robust and easier to read, and either the problem is gone, or you'll have a better chance of locating the problem.

FWIW: I'm puzzled by AsyncClient.BUFFER_SIZE, it appears only once in the code shown; is it the size required to hold the length part only?

Hope this helps.

Luc Pattyn

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Re: C# Socket.BeginReceive/EndReceive

staticv7-Sep-09 22:02

staticv

7-Sep-09 22:02

Can you please provide example code, a tutorial, anything else?

Thanks

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Do, or do not. There is no 'try'.

Convert doc file to image file

Member 46007157-Sep-09 0:19

Member 4600715

7-Sep-09 0:19

Hello,

I need to convert the doc file into an image file.
I do not want to use the print functionality (Microsoft.office.interop) as the print out remains opened on the desktop
OR
I should say how can I close the print out of the file so that client do not come to know about that?

Thanks & Regards,
Sheetal Rawat

Re: Convert doc file to image file

Christian Graus7-Sep-09 0:36

Christian Graus

7-Sep-09 0:36

Member 4600715 wrote:
I need to convert the doc file into an image file.

I don't think there's anything built in to do that, not even in the interop stuff. Your best bet. I'd think, is in taking a screenshot. Or printing to PDF.

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

Please Help

itsravie6-Sep-09 23:59

itsravie

6-Sep-09 23:59

Please help me regarding this>>

I have a declaration of method like this

public ViewMethod([CreateClass] IInterfaceController controller)
{
this._controller = controller;
}

What does [CreateClass] mean/do here?

Ravie Busie
Coding is my birth-right and bugs are part of feature my code has!

Re: Please Help [modified]

DaveyM697-Sep-09 0:05

DaveyM69

7-Sep-09 0:05

~~I would imagine if you don't already have a class Controller that implements IInterfaceController then that's what you need to create.~~

[edit] See Nick's answer below. [/edit]

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)
Why are you using VB6? Do you hate yourself? (Christian Graus)

modified on Monday, September 7, 2009 6:23 AM

Re: Please Help

Nicholas Butler7-Sep-09 0:15

Nicholas Butler

7-Sep-09 0:15

It's an attribute.

Nick

----------------------------------
Be excellent to each other Smile | :)

Re: Please Help

itsravie7-Sep-09 0:17

itsravie

7-Sep-09 0:17

what kind of attribute could it be?
please help on same.

Ravie Busie
Coding is my birth-right and bugs are part of feature my code has!

Re: Please Help

Kevin McFarlane7-Sep-09 0:19

Kevin McFarlane

7-Sep-09 0:19

It looks like you're using a Dependency Injection framework such as Unity. Am I right? If so, the documentation should tell you.

Kevin

Re: Please Help

itsravie7-Sep-09 0:38

itsravie

7-Sep-09 0:38

the defination for createnew is

public sealed class CreateNewAttribute : ParameterAttribute
{
public CreateNewAttribute();

public override IParameter CreateParameter(Type annotatedMemberType);
}

what does it mean? i m not getting
Frown | :(

Ravie Busie
Coding is my birth-right and bugs are part of feature my code has!

Re: Please Help

Not Active7-Sep-09 2:59

Not Active

7-Sep-09 2:59

Take some time to actually learn, don't just copy and paste.

only two letters away from being an asset

Re: Please Help

Nicholas Butler7-Sep-09 0:20

Nicholas Butler

7-Sep-09 0:20

It's a custom attribute - you'll have to look for the class CreateClassAttribute in your source.

Nick

----------------------------------
Be excellent to each other Smile | :)

Re: Please Help

DaveyM697-Sep-09 0:23

DaveyM69

7-Sep-09 0:23

I never considered that as I've never used (or needed to) an attribute on a parameter, I didn't even know you could! Something new learned today Big Grin | :-D

Re: Please Help

Nicholas Butler7-Sep-09 0:39

Nicholas Butler

7-Sep-09 0:39

Me too

Nick

----------------------------------
Be excellent to each other Smile | :)

Problem in setup project [modified]

xodeblack6-Sep-09 23:55

xodeblack

6-Sep-09 23:55

Hi All

I am adding app.config file in application folder of setup project for creating installer.
after installing application when we run it ..if gives following error

The Key ConnectionString does not exist in the app setting configuration section

but when I run application in Dotnet.it runs fine but when run after installing then there is above error occurs

here is app.config file

<configuration>
  <appSettings>
    <add key="ConnectionString" value="data source=localhost\sqlexpress;initial catalog=SFM;integrated security=SSPI;persist security info=False;packet size=4096" />
  </appSettings>
</configuration>

Thankz in Advance
Regards
Kashif
Rose | [Rose]

modified on Monday, September 7, 2009 6:05 AM

Re: Problem in setup project

Keith Barrow7-Sep-09 0:02

Keith Barrow

7-Sep-09 0:02

Unless I misunderstand the error is correct:

The Key <big>ConnectionString</big> does not exist in the app setting configuration section

as in

<add key="<big>Main.ConnectionString</big>" value="...

the key is "Main.ConnectionString"

Hope this give you the answer you need!

Re: Problem in setup project

xodeblack7-Sep-09 0:09

xodeblack

7-Sep-09 0:09

First of all thankz for your reply
Sorry keefb
it is my written mistake in question .......In project I am using same key .........now I corrected my question ...please check it again ......In app.config the key is ConnectionString .........and I also use ConnectionString (Same variable) in Code file ............Now please check it and can you tell me where is problem ....
why error occurs that I mentioned in first post

Blush | :O

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