I would like to know how to convert a unisgned byte to signed byte
Atm I got this
a
Function readSignedByte() As SByte
'-128/127
Dim b As SByte
[Code]....
it doesn't work one that well works for numbers positive over 127 if lets say ReadByte() has 128 it would give overflow error which I don't want it to give I would like it to overflow the number to negivate value aka its signed value.
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)?
I'm working with byte arrays and building and disassembling Int16/UInt16 and Int32/UInt32 from them. I'd like to not worry about the Sign bit until I return the final value and just have the code return the appropriate value for the data type that was requested to be converted to/from the byte array
View 3 RepliesI have an array of Bytes. Most of these are interpreted as Unsigned. On certain occasions I need to interprete the byte as signed. Why can't Byte convert to SByte? What I'm doing: I'm trying to program a disassembler for an 8-bit video game ROM. My program reads the ROM and processes each instruction. The instructions are interpreted as unsigned. Some arguments for instructions would be treated by two's complement in the original hardware, however, to make a signed number.
View 8 RepliesI need to be able to write signed bytes to a serial port using SerialPort.Write() method, except that method only takes byte[] arrays of unsigned bytes, how would i write a signed byte to the serial port?For what I'm working on the particular command takes values from -1700 to 1700.
View 1 RepliesHow can I write a signed byte (sbyte) to unmanaged memory using VB.NET? I can use Marshal.WriteByte() to write an unsigned byte, but there doesn't appear to be an overload for signed bytes.
View 1 RepliesWhy does C# define Byte+Byte=Int32 instead of Byte+Byte=Byte like VB?
View 1 RepliesI need to parse a binary stream in .NET to convert a 16 byte unsigned integer. I would like to use the BinaryReader.ReadUIntXX() functions but there isn't a BinaryReader.ReadUInt128() function available. I assume I will have to roll my own function using the ReadByte function and build an array but I don't know if this is the most efficient method?
View 3 Replieshow can i, for example add a datum from the rs232 with other variable here is my code:
Dim ii As Byte
Dim c(100) As Char
c = Me.SerialPort1.ReadExisting()
[Code]....
I'm creating an emulator for a device to simulate wave forms. My challenge is that when I try to convert the output of the following code, I can't convert the Math.Sin's double output into byte values that lend themselves to the byte array format required by an existing graphing control as listed at bottom below. I''m not sure how to handle this when the sin function creates negative values but the byte values will need to be positive and basically 'shifted up' so that anything over 127 is negative. (0 - 255) unsigned. BitConverter.GetBytes has been suggested but THIS is the result of that attempt.
[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 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)
View 12 RepliesI 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]....
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]....
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].....
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'"
Why does casting a boolean to a byte in .NET give the following output?
Code Snippit:
Dim x As Boolean = 1
Dim y As Byte = x 'Implicit conversion here from Boolean to Byte
System.Diagnostics.Debug.Print( _
[Code].....
Why does True (which commonly is referred to as an integer representation of 1) convert to 255 when casted to a byte?
I'm reading bytes from a serial port but need to convert them to signed, 8-bit integers (SByte).Unfortunately, the overflow checking in VB prevents a Byte value of 255 from becoming -1 in an SByte. So, essentially, I want to do the following:
[Code]...
I have the following code:
Private Function SizeLogo(ByVal logoBytes As Byte()) As Byte()
Using originalMemStream As MemoryStream = New MemoryStream(logoBytes),
originalImage As System.Drawing.Image = System.Drawing.Image.FromStream(originalMemStream)
[Code]....
What I am trying to do is
Create 300width and 200height white bitmap Draw and center image that was uploaded into center
My problem is I am unable to save the created image. Is this a conversion issue? I've highlighted code where I think I am failing at.
I am sending data to some microchips with a serial port control using:
Code:
well, it work up to the value 9, but anything with more that one decimal place sends a byte value of the rightmost digit. So, 16 in the text box will send 6. Basically, it appears to be sending just 6, or 1 followed by 6. Is this how the serial port sends data...one digital at a time? Or, is the conversion to a byte failing?
I have a Generic List of Bytes with Hexadecimal values stored in it. for example, elements 0 to 3 contain 42 9E D1 EC which as a single, is equal to 79.41. I've tried using:
dim foo as string = ""
for i as integer = 0 to 3
foo = foo + system.convert.tosingle(byteArray(i)).ToString
[code].....
I am using the .NET Framework 2.0, and I am trying to code a client bot for a game called Minecraft, Originally written in Java, there have been quite a few people who have made custom multi-player servers for this game, Primarily in C#, or in a language that i've never heard of, such as Pascal.I'm looking right now at sending this:
Packet ID: 0x00 (0) As Byte
Protocol Version: 0x07(7) As byte
Username: "umby25" As String
[code].....
"Byte cannot be converted to 1-Dimensional array of byte"
I don't understand why this whole thing would work in all of the other programming languages, but not Visual basic.I have tried converting the string using the same method that one of the open source C# servers used, and it failed, telling me that the dictionary does not contain that or something.
I'm converting a stream of bytes from a network packet into a specific struct, and vice versa. For example, when converting a short back and forth, my method looks like this:
myShort = buf(0) + (buf(1) * 256)
or the other direction:
buf(0) = myShort mod 256
buf(1) = myShort 256
When it comes to a 4 byte integer, after some experimentation I found that converting from the byte array to integer is done this way:
myInt = buf(0) + (buf(1) * 256) + buf(2) + (buf(3) * 256)
Basically adding two shorts together. I'm not quite sure to do the reverse of that, to fill the 4 bytes from myInt.
I am working on a mini project that requires me to take a 8 byte hex string that I received from the Serial Port and convert it into a Byte Array and display it on the screen.An example of the string that I receive is 01050001FFFF8FFB
I am currently using the System.Text.ASCIIEncoding.ASCII.GetBytes(str) to help me achieve this. However I realised that if this does not support extended ASCII so whatever byte that is > 7F, I will not get the right value.My current code is as follows:
vb
Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
Dim str As String
[code]....
I have a hexadecimal value
07A5953EE7592CE8871EE287F9C0A5FBC2BB43695589D95E76A4A9D37019C8
Which I want to convert to a byte array. Is there a built in function in .NET 3.5 that will get the job done or will I need to write a function to loop through each pair in the string and convert it to its 8-bit integer equivalent?
Is there a way to convert byte values to binary so i can read the values from the bits themselves? I have some byte whose values are 00 09 and I'd like to convert the values to bits to be like this : 0000 0000 0000 1001. Then I'd like to read the value of first 2 bits and the remaining 14 bits separately.
View 10 RepliesI have been trying to compute the checksum for a line of hex code. This is to create a hex file which will be loaded onto an embedded micro.Some of you guys may not know how this is done so very briefly:
a line of hex bytes:
: 10 01 00 00 21 46 01 36 01 21 47 01 36 00 7E FE 09 D2 19 01 40
The underlined bytes are taken and summed. (in this case the decimal 960). and the bold is the checksum Only the 8LSB (or single least significant byte) is needed to compute the checksum... which in this case, 960 = 03C0 in hex, so only C0 is needed.Two's complement is then taken:
step 1) logical not of C0 which is
step 2) add one (integer)
BIN...........DEC...HEX
[code]....
So here is the code I have been using: (quick mention that in the string passed, the hex bytes are all grouped together, there are no space characters)
Public Sub CreateLine(ByVal Data As String)
'Dim BDataArray(DataLength) As Byte
Dim IDataArray(Data.Length) As Integer
[code]....
where i get into trouble is where i commented 'i get into trouble'. My code works, but it's rather crude Now, in that line i first convert the hex value (string) "SChecksum" into an integer. I want to NOT this, so I get my step 2 from my explanation. However, the results appears to be a signed logical NOT. which gives me the wrong answer. My hashed togther version simply subtracts 256 before the not, in order to give me the correct answer.
Basically, I would love for someone to chime in and point out the flaws in my function, and push me towards figuring out the 'proper' way of doing this. Also I can't quite wrap my head around what would happen in the case a string were passed to my function that is over 16 bits, but I imagine I would have to subtract a larger value than 256, before doing the NOT in this case?(whilst we're on the subject of functions, I've used a 'sub', in which case should I used a sub, and which case should I use a function?).
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 Replies
