Detecting NewLine characters in a string.

[alex21]

I am trying to write a function for determining the data type of columns in a delimited file.

However my function is not detecting a newline and exiting the loop after the end of the first line.

* 'del_2' is equal to a new line character, i have tested this using a small bit of code

if del_2 = ControlChars.NewLine then
  MessageBox.Show("It is a newline")
end if
 

and got the message, and i know the newline characters are at the end of each line in 'filecontents' as i am adding them manually.

Public Shared Function DetermineColumns(ByVal filepath As String, ByVal delimiters As KeyValuePair(Of String, String)) As List(Of KeyValuePair(Of String, Type))
        Dim result As New List(Of KeyValuePair(Of String, Type))
 
        Dim reader As New StreamReader(filepath)
        Dim filecontents As String = ""
        While reader.EndOfStream() = False
            filecontents = filecontents & reader.ReadLine() & ControlChars.NewLine
        End While
        reader.Close()
        reader.Dispose()
 
        Dim del_1 = delimiters.Key, del_2 As String = delimiters.Value
 
        Dim read As String = ""
        For i As Integer = 0 To (filecontents.Length - 1) Step 1
            Dim curr_char As String = filecontents(i)
 
            If curr_char <> del_1 And curr_char <> del_2 Then
                read = read & curr_char
            Else
                If curr_char = del_1 Then
                    result.Add(New KeyValuePair(Of String, Type)(String.Format("{0}_{1}", DetermineDataType(read).Name, i.ToString()), DetermineDataType(read)))
                    read = ""
                End If
 
                If curr_char = del_2 Then
                    Exit For
                End If
            End If
        Next
 
        Return result
    End Function

Thanks for any help, Alex.

[MrMancunian]

Did you check the length of (filecontents.Length - 1)? I'm guessing from your explaination it's 1...

Steven

[alex21]

Nah there are many newline characters before the end of the stream, and filecontents.Length - 1 prevents an IndexOutofRange exception which i would get if i removed the - 1.

And i know the newline characters are there as i can use them to manipulate the string, such as filecontents.Split(ControlChars.NewLine) will split the string in the correct places.

My only explanation is the way i am reading characters one by one, im thinking new line characters are longer then one character?

[MrMancunian]

Check your code between line 26 and 28. This is how I read it: Whenever it enters that If-clause, you exit the for...next-loop, which means that your function will end...Is that what you want?

Steven

[alex21]

yeah as soon as it hits the newline i want it to send, however the function doesn't end and this is the problem.

Thanks

[MrMancunian]

So, why don't you add an Exit For to the part where the NewLine is intercepted?

Steven