Open multiples csv files in the folder using vb.net - vb.net

Question

The following codes below should work to load all csv files data in the datagridview by why I am getting the error of the method of operation is not implemented. Here are the codes. Do u guys have any solution
Imports System.IO
Imports System.Text
Public Class ReadBo
Public Shared Function ReadFile(ByVal FilePath As String) As DataTable
Try
Dim pathway As String() = Directory.GetFiles(FilePath)
Dim dt As New DataTable
dt.Columns.Add("File name")
For item As Integer = 0 To pathway.Length - 1
Dim files As New FileInfo(pathway(item))
Dim dr As DataRow = dt.NewRow()
Dim Lines As String() = File.ReadAllLines(files.ToString())
Dim Fields As String()
Fields = Lines(0).Split(New Char() {","})
Dim Cols As Integer = Fields.GetLength(0)
If item = 0 Then
For i As Integer = 1 To Cols
dt.Columns.Add("Col" & i, GetType(String))
Next
End If
For index As Integer = 0 To Lines.GetLength(0) - 1
Fields = Lines(index).Split(New Char() {","})
dr = dt.NewRow()
dr(0) = files.Name
For f = 1 To Cols
dr(f) = Fields(f - 1)
Next
dt.Rows.Add(dr)
Next
Next
Return dt
Catch ex As Exception
MessageBox.Show("Error is " + ex.ToString())
End Try
End Function
End Class
Imports Task2.ReadBo
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Try
DataGridView1.AutoGenerateColumns = True
Dim initialPath As String = "C:\Users\ng.yipeng\Desktop\Task2"
FolderBrowserDialog1.SelectedPath = initialPath
If FolderBrowserDialog1.ShowDialog() = DialogResult.OK Then
TextBox1.Text = FolderBrowserDialog1.SelectedPath.ToString()
Me.DataGridView1.DataSource = ReadFile(TextBox1.Text)
End If
Catch ex As Exception
MsgBox("Error: " & ex.Message)
End Try
End Sub
Private Function ReadFile(p1 As String) As Object
Throw New NotImplementedException
End Function
End Class