Question

I am using asp.Net MVC application to upload the excel data from its CSV form to database. While reading the csv file using the Stream Reader, if line contains lower case letter followed by Upper case, it splits in two line . EX.

Line :"1,This is nothing but the Example to explanationIt results wrong, testing example"
This line splits to :
Line 1: 1,This is nothing but the Example to explanation"
Line 2:""
Line 3:It results wrong, testing example

where as CSV file generates right as “”1,This is nothing but the Example to explanationIt results wrong, testing example”

code :
  Dim csvFileReader As New StreamReader("my csv file Path")
     While Not csvFileReader.EndOfStream()
                        Dim _line = csvFileReader.ReadLine()

                    End While

Why should this is happening ? how to resolve this.

Answer 1

When a cell in an excel spreadsheet contains multiple lines, and it is saved to a CSV file, excel separates the lines in the cell with a line-feed character (ASCII value 0x0A). Each row in the spreadsheet is separated with the typical carriage-return/line-feed pair (0x0D 0x0A). When you open the CSV file in notepad, it does not show the lone LF character at all, so it looks like it all runs together on one line. So, in the CSV file, even though notepad doesn’t show it, it actually looks like this:

' 1,"This is nothing but the Example to explanation{LF}It results wrong",testing example{CR}{LF}

According to the MSDN documentation on the StreamReader.Readline method:

A line is defined as a sequence of characters followed by a line feed (“\n”), a carriage return (“\r”), or a carriage return immediately followed by a line feed (“\r\n”).

Therefore, when you call ReadLine, it will stop reading at the end of the first line in a multi-line cell. To avoid this, you would need to use a different “read” method and then split on CR/LF pairs rather than on either individually.

However, this isn’t the only issue you will run into with reading CSV files. For instance, you also need to properly handle the way quotation characters in a cell are escaped in CSV. In such cases, unless it’s really necessary to implement it in your own way, it’s better to use an existing library to read the file. In this case, Microsoft provides a class in the .NET framework that properly handles reading CSV files (including ones with multi-line cells). The name of the class is TextFieldParser and it’s in the Microsoft.VisualBasic.FileIO namespace. Here’s the link to a page in the MSDN that explains how to use it to read a CSV file:

http://msdn.microsoft.com/en-us/library/cakac7e6

Here’s an example:

Using reader As New TextFieldParser("my csv file Path")
    reader.TextFieldType = FieldType.Delimited
    reader.SetDelimiters(",")
    While Not reader.EndOfData
        Try
            Dim fields() as String = reader.ReadFields()
            ' Process fields in this row ...
        Catch ex As MalformedLineException
            ' Handle exception ...
        End Try
    End While
End Using