.net - Find Location Of A Short Sequence Of Bytes In Byte Array?
Jan 15, 2011
How can I efficiently find the location of the first instance of a four byte sequence within a byte array? Is there something more efficient than looping through the whole array, or a built-in method?
I'm searching through a byte array for a pair of CrLF. I can't convert it to string for an InStr first because I need the position of it in the original byte array.
I am trying to figure out the location of this, as it delimits between a string portion and a binary portion, similar (well, exactly like for this part of it) to an HTTP header. There is a string portion, and two CrLf before the content begins.
I have a byte array and I need to get 4 bytes from it at a certain location(16) but I don't want to convert it to a integer or anything just keep it as 4 bytes to store in a variable.
I have a byte array containing bytes from a file(see my last questionnow I want to get the second lot of 4 bytes from the array and convert them to an integersomething like bytearray.get(4[start],4[length])
I am trying to copy a byte array into a Class that is in a third party library
Dim usr As New RSI_USER_RECORD Dim ba(RSI_USER_RECORD.RSI_LEN_USER_REC - 1) As Byte 'populate ba here usr = ba 'how can I do this? Is this even possible?
Here is the definition of the class (from Reflector)
I create my algorthm and its finished but there is a problem, it encrypte all text and all text in a file but after decryption when i open my file (a video file)the player show all information about file(duration,size and ect) currectly but it dont play that my program encrypt and decrypt byte by byte and place a asci code in bytes(0 to 255)
Extract the most right &HxxFF as SByte (signed)Extract the left &H7Fxx as Byte (unsigned) Identify if the most left &H8xxx is positive or negative (bool result)?
From my Windows Service I am passing a well-formed XML string to a Java Web Service. The Java Web Service will process the data and return me a status code. Though I am passing a well formatted XML file. I am getting an error from the Java Web Service of:
1. i need to find the place / city / location from IP address. does anyone know about this?
2. I want to know if there is any way to get a short URL for the db entities(i.e; if i press my website and type a db content it should go to a new page)for ex i have a site called [URL] here in actual code if i press [URL], it redirect to new page to display the content of abc.Now, what i want is i need to type [URL] and it should redirect to new page with info abc.
I have a function that returns a byte(), the only problem is that the array most times is to long and has 4 or 5 excess null bytes. I want to remove them and tried everything, but I cant seem to find anything that works.
I need to read a binary file. The Byte-Ordering in this file is different from the Intel-Standard. In good old FORTRAN I've used Equivalence-Statement in such cases (For example Defining a 4-Byte-Integer-variable and 4 Bytes at the same memory location / read the file as bytes / store them in the neccessary order / access the memory using the Integer-Variable). In VB dotnet I programmed a solution using shift-operators:
The relevant code below is not achieving what I hoped it would. I intend for 1. SerialPortBufferTemp to be used as the container for each Serial Port Read. 2. _buffer should contain the resultant array from two separate Reads, the second appended directly after the first.
(E.g. 60 bytes read on the 2nd Read will be appended to the 168 bytes received on the first Read (228 total resultant byte length)) The problem with my code below is that _buffer has increase in size from 300 bytes to 600 bytes, skipped bytes 168 to 300 (leaving them all zeros) and added the remaining 60 bytes from the second read beginning at _buffer[300].
private List<byte> _buffer = new List<byte>(); byte[] SerialPortBufferTemp = new byte[300]; serialPort1.Read(SerialPortBufferTemp, 0, iBytesRead); if (iValidRecordCtr == 0) { _buffer.Clear(); [Code] .....
I am trying to Convert a data field stored as IMAGE ( SQL Server 2000) using Java to a byte array using VB.NET Java uses signed numbers for a Byte array where as VB dosent. Can somone point me to how I can covert java byte array to VB byte array?
I have 2 byte arrays. I want to merge these two byte array into 1 byte array.Usually, I just create a new byte array with length = byte array #1 + byte array #2. Then copy byte array #1 and #2 to the new byte array.do I have more efficient way to merge 2 byte array using VB.NET and .Net 4?
I would like to create a function so that I can pass a string and it will return me the binary value, I will use this later in other parts of the script but I am getting an error that I don't understand.
Private Function ConvertToMD5(ByVal OldPassword As String) As Byte Dim NewPassword As String = "" 'The string we wish to encrypt
[code]....
On the "Return hashedDataBytes I get "Value of type '1-dimensional array of Byte' cannot be converted to 'Byte'"
I have a byte array that I convert into a string like so Dim byt As Byte() = New Byte(255) {} s = New String(Encoding.ASCII.GetChars(byte))My question is when I look at the string in a debuger its clearly a normal string but when I compare it to what I know its supposed to be it doesnt equal. So i did a quick check and for some reason its return a string thats the length of 256 characters. So i did a s.trim and it still is 256 characters long.
given my code below, I'm trying to figure out how to create an array of 1 byte containing 7 bits. So the byte in the array would contain 0111111 to correspond to mData_Out's boolean values. How would I change the following code? [Code]
I am trying to get a count of all the times a byte sequences occurs in another byte sequences. It cannot however re-use a bytes if it already counted them. For example given the string let's assume the byte sequence was k.k it would then find only 3 occurrences rather than 5 because they would be broke down like: [k.k].[k.k].[k.k]. and not like [k.[k].[k].[k].[k].k] where they over lap and essentially just shift 2 to the right.
Ideally the idea is to get an idea how a compression dictionary or run time encoding might look. so the goal would be to get down to just 2 parts, as (k.k.k.) is the biggest and best symbol you can have.
Write a function that will take one integer input parameter, create a sequence of numbers stored in an array from 0 to that number, and the numbers are a summation. For example, given 7
I didn't think it fair to post a comment on Fredrik Mörk's answer in this 2 year old post, so I thought I'd just ask it as a new question instead..NB: This is not a critiscm of the answer in any way, I'm simply trying to understand this all before delving into memory management / the marshal class.
In that answer, the function GetByteArray allocates memory to each object within the given array, within a loop.Would the GetByteArray function on the aforementioned post have benefited at all from allocating memory for the total size of the provided array:
Dim arrayBufferPtr = Marshal.AllocHGlobal(Marshal.SizeOf(<arrayElement>) * <array>.Count)
I just wonder if allocating the memory, as shown in the answer, causes any kind of fragmentation? Assuming there may be fragmentation, would there be much of an impact to be concerned with? Would allocating the memory in the way I've shown force you to call IntPtr.ToInt## to obtain pointer offsets from the overall allocation pointer, and therefore force you to check the underlying architecture to ensure the correct method is used*1 or is there a better way? (ToInt32/ToInt64 depending on x86/64?)
*1 I read elsewhere that calling the wrong IntPtr.ToInt## will cause overflow exceptions. What I mean by that statement is would I use:
Dim anOffsetPtr As New IntPtr(arrayBufferPtr.ToInt## + (loopIndex * <arrayElementSize>))
I've read through a few articles on the VB.Net Marshal class and memory allocation; listed below, but if you know fo any other good articles I'm all ears![URL]..
is there is any direct method or function in array class that can check if any given byte array is a subarray of other array?or should i loop through the each byte of main array to see if smaller array exists in that or not?
given the following Sub, how would I initialize byte array 'temp'to zeros and give it the length of the incoming byte array passed into the subroutine?
Sub ReceivePacket(ByVal buffer As Byte()) Dim temp() As Byte 'initialize to zeros and length of buffer temp = buffer.Skip(17).ToArray() End Sub
I have a simple problem (I think). I would like to get the CRC of this array of bytes
0x0 0x7E or 0 7E or 0
Anyway the one calculator I use gives me: 78F0 or 78 F0 (Hex). Anyway, I think its CRC16 but im not sure. So if anyway can show me some code to give me a CRC calculation that matches (78 F0 or 78F0), that would be great, Im not sure if you have to include 7E or not
