How can I improve my hex-based conversion - string

Question

I was facing a problem where I got data (String) from a database with Linebreaks as (Hex) 0D. I displayed this data in a Textbox, which did not use the 0D as a linbreak. I found that the Textbox needs 0D-0A (LF & CR, dont know which is which) to actually show the new line. To solve this problem I came up with the following code.
Private Function convertString(txt As String) As String
Dim data = System.Text.Encoding.Default.GetBytes(txt)
Dim hexString As String = BitConverter.ToString(data)
hexString = hexString.Replace("0D", "0D-0A")
Dim arr As [String]() = hexString.Split("-"c)
Dim array As Byte() = New Byte(arr.Length - 1) {}
For i As Integer = 0 To arr.Length - 1
array(i) = Convert.ToByte(arr(i), 16)
Next
Return System.Text.Encoding.Default.GetString(array)
End Function
Explanation/procedure:
1. Convert String to ByteArray
2. Convert ByteArray to Hex-String (Hex-Chars separated by '-' )
3. Adding the missing lf or cr by replacing the solo one
4. Convert Hex-String back to ByteArray
5. Convert ByteArray back to String
Now my question:
I am pretty sure there is a better way to do that. How can I simplify those lines of code?

Answer 1

You should be able to just Replace vbCr with vbCrLf:
Dim txt = "This is a" & vbCr & "test"
Encoding.UTF8.GetBytes(txt).HexDump()
gives (HexDump is a custom utility method, but not relevant to the question):
00000000 54 68 69 73 20 69 73 20 61 0D 74 65 73 74 This is a·test
Dim txt2 = txt.Replace(vbCr, vbCrLf)
Encoding.UTF8.GetBytes(txt2).HexDump()
gives:
00000000 54 68 69 73 20 69 73 20 61 0D 0A 74 65 73 74 This is a··test
So, your whole method would be:
Private Function convertString(txt As String) As String
Return txt.Replace(vbCr, vbCrLf)
End Function