Finding HEX value at a specific offset in VB.net

Question

I'm trying to figure out how to read a section of bytes (Say 16) starting at a specific address, say 0x2050. I'd like to get the 16 bits output in hex values into a label.

I've been trying to figure out BinaryReader, and FileStreams but I'm not entirely sure what the difference is, or which one I should be using.

*I've seen a lot of threads mentioning file size could be an issue, and I'd like to point out that some files I'll be checking may be up to 4gb in size.

---

I've tried the following:

Dim bytes() As Byte = New Byte(OpenedFile.Length) {}
ListBox1.Items.Add(Conversion.Hex(OpenedFile.Read(bytes, &H2050, 6)))

But this simply writes 6 bytes to the file, and I'm not sure why. There is no output in the listbox.

Answer 1

How about something like the following?:

Sub Main()
    Dim pos As Long = 8272
    Dim requiredBytes As Integer = 2
    Dim value(0 To requiredBytes - 1) As Byte
    Using reader As New BinaryReader(File.Open("File.bin", FileMode.Open))
        ' Loop through length of file.
        Dim fileLength As Long = reader.BaseStream.Length
        Dim byteCount As Integer = 0
        reader.BaseStream.Seek(pos, SeekOrigin.Begin)
        While pos < fileLength And byteCount < requiredBytes
            value(byteCount) = reader.ReadByte()
            pos += 1
            byteCount += 1
        End While
    End Using

    Dim displayValue As String
    displayValue = BitConverter.ToString(value)
End Sub