I am working on a project and came to a junction. I have various data in a object array, myObj().
How can one convert Object Array to Byte Array
I dont know if i should be using Memory Stream, Buffer, etc.
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]..
in my project I use an Excel workbook as template. Right now, this workbook is located in the same directory as the exe-assembly and can be opened and manipulated by the user. To avoid this, I thought about adding the workbook to a ressource. That works. Problem: how can I convert the resulting byte-array/stream back to a workbook-object?I tried like this, but - obviously - the conversion fails:
Public Shared Sub test()
Dim wkb As Excel.Workbook
Dim bytes As Byte() = My.Resources.Template_1
[code]....
How do I convert between an image object and Byte Array?
View 1 RepliesI am needing to write data to a usb device. The USB device uses a byte array (DataArray() as byte) to store the data. How can I assign a struct object (myStruct(0)) to the byte array. I run into the error "Value of type byte cannot be converted to 1-dimensional array of byte" when I try to cast the struct as a byte.
View 10 RepliesI am getting this warning in my code, and for the most part I have ignored it.
Friend Sub StartTablet()
Dim success As Boolean
Dim eventObject As IntPtr = IntPtr.Zero
[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?
View 2 RepliesI have 9 1-dimensional arrays of bytes and 1 of them is empty, I want to make the empty one equal to the others put together like you would a string:
Dim bla As String = "bla" & "bla" & "bla"
'now bla = "blablabla"
but instead:
[Code]......
How do I read a raw byte array from any file, and write that byte array back into a new file?
View 3 RepliesA c# class's single dimension byte array contains socket level instrument sensor data as per:
public static byte[] frameData
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?
View 2 Repliesgiven 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 an array defined As string and the value stored in site is like "7E", "A1" and so on. But in order to send out this array through serial port. I need to change the the array to As Byte instead of using As String. How can I convert it?
View 8 RepliesThe following image or RTF file illustrates how I'm trying to transform an input Byte array into an output array of Booleans. This is basically what I have listed below. figure out how to get from one array to the next while shifting values of bytes within 8 byte groupings to shift low order to high order or vica versa. What I mean by that is best seen by looking at the illustration of actual input an required output. The reason for this is that the hardware devices have registers and the display which can be seen in the links above needs to convey the disabled sensor cable cell locations.
[Code]...
The code below contains the actual data I receive as input and the required output to send to a hardware device. The application requires incoming boolean values be processed in sets of 8, corresponding to their resultant Byte value. The first incoming boolean value must assume the least significant position of the resultant Byte Value. False, False, True, True, True, True, True, True will result in a Byte Value of 252 if viewing the resultant Byte value in the debugger. Those boolean values will be reversed in order to become True, True, True, True, True, True, False, False. What I can't figure out below is how to accomplish this in the form of masking or shifting the values to accomplish this.
[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.
Here is source so far:
[Code]...
Objective: Combine byte arrays, read specific sections, and then cut byte array at specified point.
Private Sub DataArrival(ByRef aBot As xyzSocket, ByRef theData As Byte())
Dim RDLength As Int32
If aBot.ReceivedData Is Nothing Then[code]....
I'm not sure if I have this right to begin with because I can't test it without having it completed.
how to upload file using fileupload control into sql database. I have class where i created insert function and getting info frm the .aspx.vb file
Class File
========
Imports System
Imports System.Data
Imports System.Data.SqlClient
[coe]....
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?
View 2 RepliesI 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'"
How could you convert a IntPrt to a Byte Array (Byte()) ?
View 19 RepliesI 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.
View 1 Repliesgiven 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]
View 8 RepliesI am creating a dll with all the functions and subroutines that I use all the time and I decided to create a function that I can pass different types of array to so the function obviously (or not) would have an array of type object. Now I no you can pass any type into an object type but when I pass an integer array into an object array I get an error.
value of type '1-dimensional array of integer' cannot be converted to '1-dimensional array of object' because 'integer' is not a reference type.
Shared Function CompareArray(ByVal FirstArray() As Object, ByVal SecondArray() As Object, Optional ByRef ErrorMessage As String = "") As Boolean
Dim IntArrayOne() As Integer = {1,2,3,4,5} Dim IntArrayTwo() As Integer = {1,2,3,5,6} Dim IsSame As Boolean = False IsSame = CompareArray(IntArrayOne(), IntArrayTwo())
what's the difference between variable array and object array?
View 7 RepliesI 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.
View 1 Repliesi'm working on something to get the average color from an image and the code i have puts all the rgb values into a byte array, so the values are being stored as (r,g,b,r,g,b,r,g,b,r,g,b,r,g,b,etc). how would i loop through each r value to add them to another array to then be able to calculate the average (and so forth for g and b as well).
View 4 RepliesHow to convert byte array to pdf using asp.net.
my code is
Response.Clear()
Response.ContentType = "application/pdf"
Response.AppendHeader("Content-Disposition", "inline;filename=data.pdf")
[Code].....
Dim B() As Byte = File.ReadAllBytes(o.FileName) 'do Work here.<br/> B = New Byte() {0}
View 11 Repliessince 2 week i'm stuck to do this thing. Actually i need to display image from oracle database into the picturebox. My oracle database got table name "STAFF_PHOTO" and the column of photo is "PICTURE". The image already converted into ByteArray. I'm already make a connection and success but the image stil cannot display. already refer to the tutorial but still stuck. I'm also try to use Memorystream but still can't.
View 11 Replies
