This example shows how to replace unprintable characters with spaces

[nandagopal]

this simple function for converting unprintable characters with ASCII codes between 0 and 31 into spaces. It builds a string containing the disallowed characters surrounded by square brackets. It then uses regular expressions to match any of those characters and replace them with spaces.

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Private Function CleanseData(ByVal textToCleanse As String, _
    _
Optional ByRef changeCount As Integer = 0) As String
    ' Create illegal character string
    Dim badChars As String = String.Empty
    For index As Integer = 0 To 31
        ' Use ChrW instead of Chr to avoid boxing
        badChars &= ChrW(index)
    Next

    ' Build RegEx pattern - square brackets say match any
    ' one of them
    Dim pattern As String = "[" & badChars & "]"

    ' Are there any illegal characters
    If Regex.IsMatch(textToCleanse, pattern) Then
        ' Count them
        changeCount = Regex.Matches(textToCleanse, _
            pattern).Count
        ' Convert them to spaces
        textToCleanse = Regex.Replace(textToCleanse, _
            pattern, " ")
    End If
    Return textToCleanse
End Function 'CleanseData