Check Packet Size Of TCP Data Before Reading Next Byte In Stream
May 25, 2009
I am sending data to server via TCP IP Connection. I am using a continuous loop at the server end - that accepts new clients and while streams can be read, it reads data stream.
The data is sent from the client with 2 leading bytes of data that represent the size of the packet of data sent and type of data.
My question is: how do I retrieve the size of the data packet and then check that this amount of data has been retrieved?
[Code].....
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May 25, 2009
I am sending data to server via TCP IP Connection. I am using a continuous loop at the server end - that accepts new clients and while streams can be read, it reads data stream.
The data is sent from the client with 2 leading bytes of data that represent the size of the packet of data sent and type of data.
My question is: how do I retrieve the size of the data packet and then check that this amount of data has been retrieved?[code]...
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Feb 2, 2011
I have a packet that I need to send to a client with an ID of 255. I've had no problems sending packets with IDs of 0, 1, and 2. The ID has to be 255. For some reason, after the translation has happened, both me with my server, and the client, get "63" for any Id greater than 127.
This is the code I am using:
Console.WriteLine(Asc(System.Text.ASCIIEncoding.ASCII.GetString(System.Text.ASCIIEncoding.ASCII.GetBytes(Chr("255")))))
Now, This is an overly complicated version of what the server does. You may consider this a bit unnecessary but the inverse functions performed are for your viewing reasons only.
Where it says "255" is the Packet Id I need sent in the format above. As I said, anything larger than 127 returns "63".
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May 23, 2011
I need to read signed and unsigned 8 bit, 16 bit and 32 bit values from a file stream which may be little-endian or big-endian (it happens to be a tiff file which carries the byte order indicator at the start).I initially started by writing my own functions to read the values and was able to do so for unsigned values. e.g.
Public Function ReadUInt32() As UInt32
Dim b(4) As Byte
input.Read(b, 0, 4)
[code]....
But then I started looking at signed values and my brain broke.As an alternative, I found the IO.BinaryReader which will let me read signed values directly but doesn't seem to have any way to indicate that the data is big-endian or little-endian.Is there a nice way of handling this? Failing that, can someone tell me how to convert multiple bytes into signed values (in both byte orders)?
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Mar 3, 2009
i need to read a large file stream binary my code is Dim sr As New IO.FileStream(srcFile,
[Code]..
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Jul 4, 2011
I'm writing a program which uses sockets, Now the issue I'm having is, If the packet received is over a certain size, the socket then fails to receive anymore packets/data after it.
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Dec 8, 2009
I just converted the following code from c# to vb.net. It is functional and works correctly with my company's firmware/devices. My next challenge. Previous serialport code used much more readable structs which where then converted (after building a packet) into byte() automatically as part of the serialport encoding. (this is my understanding)How could I
1. morph byte arrays 'ToSocket' and 'ToMTP' below into structs and
2. convert into byte array for Socket.BeginSend(byte(),.....) to stream out to remote devices?
Imports System.ComponentModel
Imports System.Text
Imports System.Net.Sockets
[Code]....
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Mar 7, 2012
basically I'm sending and receiving both images, strings and files over a client/server connection. I can easily use a protocol for string commands but I cannot distinguish between the incoming data [if data is image or whatever and then follow onward instructions].So how do I make a packet using Dim buffer as byte()?
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Aug 2, 2010
I've been using some code which I found on the net, and have noticed that the first byte is never recieved. Annoyingly, this contains the MAC addresses, which is the bit I want. Below is the relevant snippits:
Public Sub [Start]()
If m_Socket Is Nothing Then
Try
[Code].....
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Nov 11, 2010
I am having trouble with a socket client application written in vb.net using Visual Studio 2005. The client connects to a C language socket server that is running on OpenVMS. The problem that I have is that when the server sends a packet, the client does not receive the last byte (of every packet!). I can dump the packets on the network and the data is all there. My current solution is to keep my socket messages short (247 bytes) and send one extra byte past the end of my data.
I would like to include more information in my messages and I cannot find a way to make this work. If I knew 100% how long the packets will be on the network, I could work around this by including an extra byte in just the right places. However, I don't want to make any assumptions about the length of the packets.
Here is a sample of my client receive code:
Private Sub ReceiveMsg()
Dim nTotalBytes As Integer
Dim nNumBytes As Integer
[Code]....
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Feb 6, 2011
I'm working with the Minecraft Server To Client protocol documentation for a server I am making.It says the packet is 18+ bytes, but I can't seem to figure out what each byte is for.
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Feb 18, 2010
How to check the data inside this value anyone ?
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Feb 15, 2011
I have an .net application with 2 processes, communicating using a network stream.The protocol consists of a set of commands, some with parameters, which are sent through the stream to the server. The server processes the command, and sends a response.
The protocol for one of the commands looks like this:
[code]...
Usually, this works fine. Very rarely (probably once every few millions of calls), The reading side gets the wrong values. I added code to trace the values sent and received. This shows that occasionally, the reading side gets two extra bytes, with the value 0, which was not sent by the writing side. These extra bytes appear in different places, e.g. in one case they were between i1 and i2; in another they were between the first and second byte of s2. Does anyone have any idea where these 2 bytes could come from? I checked my code, and every place that writes to the stream is traced, so it doesn't look like they are actually written to the stream. It might be worth noting that s1 is always 0, in the current implementation.
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Aug 25, 2010
how to convert byte array to memory stream in vb.net.
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Mar 31, 2011
I'm working on a licensing system for my application. I'd like to put all licensing information (licensee name, expiration date, and enabled features) into an object, encrypt that object with a private key, then represent the encrypted data as a single text string which I can send via email to my customers.
I've managed to get the encrypted data into a byte stream, but I don't know how to convert that byte stream into a text value -- something that contains no control characters or whitespace. Can anyone offer advice on how to do that? I've been researching the Encoding class, but I can't find a text-only encoding.
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Jun 25, 2009
I try to read a stream and save it as byte array to add it later to zip file.this is the code that I use
Dim totalbytes As Byte() = Nothing
Dim iBytesRead As Integer
Dim sChunks As FileStream = File.OpenRead("c:myfile.wav")
Dim Totalread As Int64 = 0
[code]....
but there is something is not correct,
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May 25, 2012
in an winForm app in VS2010 win 7 compiling to x86, I try to do what Alvas.Audio seems to work. See (c# ex: [URL] for reference.
Dim data() As Byte = wr.ReadData(second * i, second)
The result give me data.length()=0. I do not have any exception, I can read format from it and whatever reader I use I got this problem.EDIT : After some tests, it seems like the uncompressed file I create in the first step (in PCM format, with .wav extension) can not be recognized by the Alvas.audio library for the second step. I must miss something around Audio file markups or something alike.
Here is the code that might be the source (basically this is step 1):
Dim functOut As String = String.Empty
Dim wr As Alvas.Audio.IAudioReader = Nothing
Dim fs As IO.FileStream = Nothing
[code]....
How can I write the resulted stream to be sure I can read it again later?
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Sep 26, 2011
How to convert memorystream byte array to csv file. I have GetExport method that converts rpt file to excelformatted memorystream and then returns that as a byte array. Is there a way to convert this byte array to a csv file? Due to some reasons I can only pass this byte array back to calling function.
Public Function GetExport(ByVal reportID As ReportID) As Byte()
Dim byteArray As Byte() = Nothing
Using expRptDoc As ReportDocument = New ReportDocument()
Dim rptFileName As String = Server.MapPath(ReportCommand.GetXMLReportPath(reportID))
expRptDoc.Load(rptFileName)
[Code] .....
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Mar 1, 2009
I am trying to play video files (atleast wmv, avi) from a byte stream in vb.net.Is it possible to direct this data at a wmp control?I have done this successfully with images & picture boxes, just need help with the video.
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Mar 29, 2010
I'm trying to read data from some local XML files and process data from them using VB.net.
The format is:
<?xml version='1.0' standalone='yes' ?>
<DataFeed>
[code].....
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May 16, 2011
Is it possible in VB to truncate a larger data type ( an int with a value greater than 255) to a smaller one, say a Byte (which only goes up to 255) in a way such that the 8LSBs of the integer are copied to the newly created byte. I have tried this using CType with the following code, however it does not work.
Dim TestByte As Byte = CType(Test, Byte)
Where the variable "Test" is an integer with a value of 419. This code always results in the Overflow exception.
[code].....
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Jul 1, 2009
I'm sending an http request through a proxy using tcp, and then using a streamreader to read the netstream...The streamreader is supposed read each line up to </html> , however it doesn't seem to be waiting for the packet/response to be fully received, as it always returns only the first 5-10 lines of HTML.If I add a breakpoint at the line "Using sr", and pause it there for a few seconds and then continue the execution, it will return the full HTML up to the </html> as it should.This is the part of my code which reads the response.
Dim sendbytes As Byte()
sendbytes = System.Text.Encoding.ASCII.GetBytes(ReqHeaders)
netstream = tcp.GetStream()
netstream.Write(sendbytes, 0, sendbytes.Length)
[code].....
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Jul 6, 2009
i am using visual studio 2008 using vb.net. I have opened an xml stream and am reading it using xmltextreader. So far so good. I am using the following code to parse the stream and to get an understanding of what it contains and how to use the info.
[Code]...
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Jun 12, 2009
My app is receiving data in blocks but I don't know what size data will be received until it is finished, unlike file reading. So my app loads the data in chunks of 1024 bytes and then stops when there is no data to read. My question is, is it possible to keep increasing the size of a byte array as the data is being received?
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Oct 29, 2009
I've got an XMLTextWriter writing to a Stream of a WebRequest. Everything works as it should:
Dim wr As WebRequest = WebRequest.Create("https://wwwcie.ups.com/ups.app/xml/ShipAccept")
With wr[code].....
How can I intercept this XML that's being written as an XMLDocument type? I tried snagging it from the stream but that gave me a 'The stream does not support reading.' exception
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Jul 20, 2011
How am I able to send a data packet from my program, to an IP Address on a certain port (using Udp).
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Jan 10, 2010
I am trying to read a packet of data which has come in from RS232. I need to be monitoring the port until data comes in to be actioned. I have been doing this fine for some time using the following code:
Dim strline As String = Nothing
Dim comPort As SerialPort
Dim bIsOpen As Boolean = False
[Code]....
The code above works without a problem unles byte 1 or two are greater than 127. Basically, all of the characters that are not converted seem to be 128-255.
I am using VB 2008 express. Clearly I need to read each byte individually and store it as a byte within an array instead of a string but i am not sure how to do this.
how to get around this either through reading bytes properly or through using a different encoding format
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Sep 24, 2010
What's the best way to convert a varying size byte array to a string, and then to convert it back?
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Dec 16, 2010
I inherited a project that includes a dialog between two applications. One in native C++ the other in VB.NET. The protocol is such that the first 4 bytes (32 bits) of the message encodes the size. However the VB.NET side never sets these first four bytes, however it does use the .net method BeginSendTo, which accepts an argument for size. Does the BeginSendTo method automatically add the size to the beginning of the message in the form of a 4 byte int?
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Jun 9, 2010
If i use a stream to modify few bytes in a file without changing the total number of bytes
does the stream rewrite all the file even if just few bytes have been replaced?
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