Convert a binary file to hex code

[Asheekay]

Basically, how do you convert a binary file to its hex code in VB.NET just like this (VB6) thread on this forum: https://www.vbforums.com/showthread....t=binary%20hex

So what I need is:

1. Read a binary file.

2. Convert each byte of the file to its ASCII value. Note that since it is a binary file, there are going to be a lot of non-printable characters in there. So A becomes 65, backspace char becomes 8 etc.

3. Convert this array of ASCII values to the array of their 2 digit HEX conversions so that 65 becomes 41 and 8 becomes 08 etc.

4. Convert this array to a string.

5. Convert this whole string back to the original binary file. (Another function for this, obviously)

Right now I have:

Dim scr_filename As String = My.Computer.FileSystem.SpecialDirectories.Desktop + "\mypic.jpg"

Dim fdata = My.Computer.FileSystem.ReadAllBytes(scr_filename)

            Dim res As String = "", fstr As String, num As Integer
            'res = System.Text.Encoding.ASCII.GetBytes(fdata)

            fstr = System.Text.Encoding.Default.GetString(fdata)

            For i As Integer = 0 To (fstr.Length - 1)
                num = Asc(fstr.Substring(i, 1))
                res += num.ToString + " "
            Next
            MsgBox(res)

Running this unholy, wicked code for a 2 kb file generates the result within one second. For a 20 kb file, it takes around 4 seconds. For a 120 kb file ... well, I executed the code and went away from the computer for more than half an hour. When I returned, the messagebox had still not appeared and the form was stuck/disabled.

How do I exorcise this code, or, perhaps sacrifice it at the alter of Elder VB.NET and get a whole fresh code to do my bidding?

[dday9]

To read a binary file, use the IO.BinaryReader class: documentation

To convert each by to its respective ASCII value, use the Text.ASCIIEncoding.GetString method: documentation

To convert the bytes to their 2 digit hex value, you do not need to first convert them to their respective ASCII values, just convert the byte directly by calling ToString and passing the "X2" format: documentation

To convert the collection to a String, use String.Concat: documentation

To convert the 2 digit hex values back to their respective Byte values, you'd call Convert.ToByte: documentation

After reading the relevant documentation and working something up, if you still have any issues feel free to reach back here with what you tried and what's going wrong.

[Niya]

    Public Iterator Function ReadBin(ByVal fileName As String) As IEnumerable(Of String)
        Using fs As FileStream = File.OpenRead(fileName)
            Using br As New BinaryReader(fs)
                Do Until fs.Position = fs.Length
                    Yield br.ReadByte().ToString("X2").PadLeft(2, "0"c)
                Loop
            End Using
        End Using
    End Function

You can do it with the above function.

Example of its use:-

Debug.WriteLine(String.Join(" ", ReadBin("d:\ax.txt")))

Note that I wrote it as an iterator function for efficiency. This way you don't have to load the whole thing into memory and then process it byte by byte. You just have to iterate the object returned by the function and it will process it as you iterate it.