How do I load data into correct data grid view columns

'DGV SETUP:

'Create an unbound DataGridView by declaring a column count.
        DataGridView7.ColumnCount = 4
        DataGridView7.ColumnHeadersVisible = True

        ' Set the column header style.
        Dim columnHeaderStyle As New DataGridViewCellStyle()

        columnHeaderStyle.BackColor = Color.Beige
        columnHeaderStyle.Font = New Font("Verdana", 10, FontStyle.Bold)
        DataGridView7.ColumnHeadersDefaultCellStyle = columnHeaderStyle

'Creates columns and sets column header names.
            DataGridView7.Columns(0).Name = "#"
            DataGridView7.Columns(1).Name = "Mapping Items"
            DataGridView7.Columns(2).Name = "Snippet"
            DataGridView7.Columns(3).Name = "Date and Time"

 With DataGridView7
                ' .AutoResizeColumnHeadersHeight
                .Columns("#").AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCellsExceptHeader
                .Columns("Mapping Items").AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
                .Columns("Snippet").AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
                .Columns("Date and Time").AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
            End With

'SAVE LISTVIEW TO A SPECIFIC FILE:

' Creates a <CSV> File
        Using csv As New System.IO.StreamWriter("C:\Users\CurrentUser\Documents\MappingData.txt", True) 'What does True do here???
            For Each Item As ListViewItem In ListView1.Items
                csv.WriteLine(String.Format("{0};{1};{2};{3}",
                                            Item.SubItems(0).Text,
                                            Item.SubItems(1).Text,
                                            Item.SubItems(2).Text,
                                            Item.SubItems(3).Text))
            Next
        End Using

'FORM LOAD EVENT: LOAD MAPPING DGV FROM TEXT FILE:

    Private Sub LOADDGV()

        Using stream As System.IO.FileStream = System.IO.File.OpenRead("C:\Users\CurrentUser\Documents\MappingData.txt")
            Using reader As New System.IO.StreamReader(stream)

                Dim line As String = reader.ReadLine()

                While (line IsNot Nothing)

                    Dim columns = line.Split(";") 'Text separator which splits to display in DGV columns (i.e. ;:," ", etc.)
                    line = reader.ReadLine()

                    Dim index = DataGridView7.Rows.Add(line)

                    DataGridView7.Rows(index).SetValues(columns)

                End While

            End Using
        End Using

    End Sub