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 RepliesI need to search a Byte array for the existence of another Byte array. The first array is large, about 30,000 bytes and the second varies but is usually between 300 and 500 bytes. I need to know the start position of the second array inside the first. For example if these were the arrays:
Code:
Array 1 Array 2
00
34
00
23 23
00 00
64 64
00 00
41 41
00
45
92
33
I would need to know the start position is 3.
Code:
For x = 0 To UBound(Array1)
If Array1(x) = Array2(0) And Array1(x + 1) = Array2(1) And Array1(x + 2) = Array2(2) Then
' Found it
End If
Next
And loop through finding it by brute force but array 2 will be a different size on each system so doing the above, although I could make it work, isn't practical. I could even do multiple if's like if I find the first byte then find the second, then find the third, and make it a little more bearable but still. Is there a simple way to find a array inside another array?
I am trying to have my program check for the existence of a registry key so I do not get a null reference exception error. The key may or may not exist depending on the computer. How can I check to see if it exists and then change its value if it does exist or skip over it to the next one if it does not exist? (I already know how to change the value part of it) Im just not sure how to check for the existence of it for example would be trying to set the value of a key that does not exist called test below... this obviously would throw a null exception error so how do I check for the existence of the key before executing these instructions and then if it does not exist it skips this and keeps going to the next code ?
Dim testkey As RegistryKey = Registry.LocalMachine.OpenSubKey("SystemCurrentControlSetTEST", True)
Dim keyval As Int32
' Set to ON
keyval = 1
testkey.SetValue("ON", keyval)
I also check the status of the registry entry on form load
Dim Test As RegistryKey = Registry.LocalMachine.OpenSubKey("SystemCurrentControlSetMYTEST", False)
'Get the reg value.
Dim Testflag As Integer = CInt(Test.GetValue("ON"))
[code]....
The application I'm writing requires the user to select a certain directory on their hard-drive (a game directory), which is saved to the Settings. If the directory is not selected, my application can't work. So, when the program starts for the first time, the directory setting will not be present, and I want my application to ask the user to select the correct directory before the application starts (the main form is shown). I used the following code in the Form_Load event of my main form:
vb.net
If My.Settings.WolfPath = String.Empty Then
MessageBox.Show("Please select your root 'Wolfenstein - Enemy Territoryetmain' mapping installation.", "Select W:ET Path", MessageBoxButtons.OK, MessageBoxIcon.Information)
[code]....
It looks pretty complicated (probably too complicated) but I wanted to make sure that the user cannot continue until a valid directory has been selected. So when the user cancels the folder selection, my application should end. If the user selects an invalid directory (it should end in "etmain") it should display a messagebox and show the folder browser dialog again. It should keep doing this until the correct path has been chosen.The problem occurs when an invalid directory is first chosen. The messagebox does show, but it shows behind all other applications! It took me a minute to figure that out, because I could not find my application anywhere, but Visual Studio still said it was running... After finally finding the messagebox behind everything else, it seems that now everything comes up behind everything else! When I click OK on the messagebox, the new folder browser dialog also shows up in the background, etc, etc. If I then choose a valid directory, the application loads the main form in the background...
I thought at first the problem would be the fact that I am running this code in the Form_Load event. A better place perhaps would be a Sub Main() from which the main form would be loaded explicitly (Application.Run(mainForm)). However, I can only select Forms as the Startup Form. If I disable the "Enable application framework" checkbox I can select the Sub Main() as Startup Object, but all the visual styles are lost...?
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 RepliesI 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]..
A c# class's single dimension byte array contains socket level instrument sensor data as per:
public static byte[] frameData
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 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]...
i have a byte array in my code which contains hex values which is readed from a bin file. now what i want to do is cut this array into equal size of 4096 bytes and made new array,s at run time and assign first (4096) byte,s to first array and so own
View 6 RepliesComing up against a brick wall with sending items over the network using sockets. I'm using Chilkat rather than the built in TCP Client / listener but thats not the issue. From point a I send through a string converted to base64 as below
[Code]...
I need to explicitly convert my byte array into IntPtr to pass it to the third-party api. I've been looking through Runtime.InteropServices namespace but didn't find anything suitable.
View 2 RepliesIs there any way using existing .NET framework classes/methods that you can sequentially read a byte array? I dont mean just using a for loop to loop through from the beginning to the end, I mean having the kind of methods that you have when working with an IO.Stream subclass, such as ReadByte. I thought I would just be able to construct a new IO.Stream class and pass it in a byte array but it seems that Stream is just for inheriting and cannot actually be used itself. I could implement my own class that just has an internal position counter and a byte array and then each time you call ReadByte on that it advances the position and returns the byte at that index... but it seems odd to have to implement such a basic thing myself.
View 1 Repliesi have a list of byte array,s what i want to do is search for a element, replace that element ,add one more element after first element.
ex for element 7D i want to add 5d after . and for element 7E i want it to replaced it by 7D and need 5E after.
I'm calling a Windows API that gives me a byte array which represents a unicode string - the problem is that if I call Text.Encoding.ASCII.Get String on it I just get the first letter of the string. The reason for this is that byte array has an empty byte between each character. I've verified that removing these empty bytes resolves the problem by just using a simple For loop to add the bytes that do have a value in into a new byte array, then calling Text.Encoding.ASCII.GetString on that and that gives me the full string I'm expecting.I'm just wondering if there is any easier way of getting the working string though without having to do a loop and create a new byte array etc?
View 2 RepliesC++ DLL MiFare.h has
MIFAREAPI_API unsinged short MIFAREAPICC MF_ReadCardBlock( DWORD dwBlkAdr, DWORD dwRdrKey, DWORD dwKeyAB, DWORD dwRspBufSz, BYTE *pRspBuf );
my decalre in VB is
<DllImport("MifareAPI.dll")> _
Private Shared Function MF_ReadCardBlock(ByVal BlkAdr As ULong, _
ByVal RdrKey As ULong, _
[code]....
but i can't get the correct data?
VS 2008 Saving a Byte Array as a resource
View 5 RepliesI have a byte array with contents from a file in it, but I want to trim / remove the first element from it [byte(0)]. I've searched for days and experimented with a hundred different methods but they don't work.
[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.
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.
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 am looking for something that will convert a byte array to a string and back, anything in-build that does it as this method would:
To string:
vb
Dim b = ByteArrSerialize(Obj, Compress, EncryptKey)
Dim sb As New System.Text.StringBuilder
For Each item In b
sb.Append(Chr(item))
Next
To byte:
vb
Dim b(0 To Len(TheString) - 1) As Byte
Dim bCount As Long = 0
For Each item In TheString
b(bCount) = Asc(item)
bCount += 1
Next
I have found a lot of examples of this kind of thing on the web but cannot get one that works - basically i am serializing to a byte array and want to store it in a string i have tried all of the System.Text.** (ASCIIEncoding,UTF32Encoding,UTF7Encoding and UTF8Encoding) in the following way:
[Code]...
i've created a new access 2007 database + added a OLE Object field, that i've then pasted images into.
in vb2008 i've connected to the database + put the table into a datatable. so far it works ok.
when i try to convert the byte array to an image, it causes an error:
'A first chance exception of type 'System.ArgumentException' occurred in System.Drawing.dll'
heres the code i'm using:
vb
Dim arr() As Byte = DirectCast(record.Item(5), Byte())
pic.Image = Image.FromStream(New IO.MemoryStream(arr))
its loading the byte array properly, but the Image.FromStream line causes the error. i've used this method before with an earlier access database + it works.
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 Replies