Visual Basic How do I read a CSV file and display the values in a datagrid?

Question

I\'m using VB 2005, how do I open a CSV file and read the columns/rows and display the values in a datagrid?

CSV file example: jsmith,jsmith@hotmail.com

I th

Answer 1

Usage:

Dim reader As New Common.CSVReader("C:\MyFile.txt")
reader.DisplayResults(dgvMyView)

Class:

Imports System.Windows.Forms
Imports System.IO
Imports System.Text.RegularExpressions

Public Class CSVReader
    Private Const ESCAPE_SPLIT_REGEX = "({1}[^{1}]*{1})*(?{0})({1}[^{1}]*{1})*"
    Private FieldNames As String()
    Private Records As List(Of String())
    Private ReadIndex As Integer 

    Public Sub New(File As String)
        Records = New List(Of String())
        Dim Record As String()
        Dim Reader As New StreamReader(File)
        Dim Index As Integer = 0
        Dim BlankRecord As Boolean = True 

        FieldNames = GetEscapedSVs(Reader.ReadLine())
        While Not Reader.EndOfStream
            Record = GetEscapedSVs(Reader.ReadLine())
            BlankRecord = True
            For Index = 0 to Record.Length - 1
                If Record(Index) <> "" Then BlankRecord = False 
            Next
            If Not BlankRecord Then Records.Add(Record)
        End While
        ReadIndex = -1
        Reader.Close()
    End Sub

    Private Function GetEscapedSVs(Data As String, Optional Separator As String = ",", Optional Escape As String = """") As String()
        Dim Result As String()      
        Dim Index As Integer
        Dim PriorMatchIndex As Integer = 0
        Dim Matches As MatchCollection = _
            Regex.Matches(Data, String.Format(ESCAPE_SPLIT_REGEX, Separator, Escape))

        ReDim Result(Matches.Count)

        For Index = 0 to Result.Length - 2
            Result(Index) = Data.Substring(PriorMatchIndex, Matches.Item(Index).Groups("Separator").Index - PriorMatchIndex)
            PriorMatchIndex = Matches.Item(Index).Groups("Separator").Index + Separator.Length
        Next
        Result(Result.Length - 1) = Data.Substring(PriorMatchIndex)

        For Index = 0 To Result.Length - 1
            If Regex.IsMatch(Result(Index), String.Format("^{0}[^{0}].*[^{0}]{0}$", Escape)) Then _
    Result(Index) = Result(Index).Substring(1, Result(Index).Length - 2)
            Result(Index) = Replace(Result(Index), Escape & Escape, Escape)
            If Result(Index) Is Nothing Then Result(Index) = ""
        Next

        GetEscapedSVs = Result 
    End Function

    Public ReadOnly Property FieldCount As Integer 
        Get
            Return FieldNames.Length 
        End Get
    End Property

    Public Function GetString(Index As Integer) As String
        Return Records(ReadIndex)(Index)
    End Function

    Public Function GetName(Index As Integer) As String
        Return FieldNames(Index)
    End Function

    Public Function Read() As Boolean
        ReadIndex = ReadIndex + 1
        Return ReadIndex < Records.Count 
    End Function


    Public Sub DisplayResults(DataView As DataGridView)
        Dim col As DataGridViewColumn
        Dim row As DataGridViewRow
        Dim cell As DataGridViewCell
        Dim header As DataGridViewColumnHeaderCell
        Dim Index As Integer
        ReadIndex = -1

        DataView.Rows.Clear()
        DataView.Columns.Clear()

        For Index = 0 to FieldCount - 1
            col = new DataGridViewColumn()
            col.CellTemplate = new DataGridViewTextBoxCell()
            header = new DataGridViewColumnHeaderCell()
            header.Value = GetName(Index)
            col.HeaderCell = header
            DataView.Columns.Add(col)
        Next 

        Do While Read()
            row = new DataGridViewRow()
            For Index = 0 to FieldCount - 1
                cell = new DataGridViewTextBoxCell()
                cell.Value = GetString(Index).ToString()
                row.Cells.Add(cell)
            Next
            DataView.Rows.Add(row)
        Loop
    End Sub
End Class