how to filter a datagridview when a database is not being used - vb.net

Question

I am able get the contents of a csv file to read into DataGridView1, but I am having trouble filtering the data from textbox2. I tried different things I have found online, but nothing has worked so far. this is what i have:
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim fName As String = ""
OpenFileDialog1.InitialDirectory = "C:\"
OpenFileDialog1.Filter = "CSV Files (*.csv)|*.csv"
OpenFileDialog1.FilterIndex = 2
OpenFileDialog1.RestoreDirectory = True
If (OpenFileDialog1.ShowDialog() = Windows.Forms.DialogResult.OK) Then
fName = OpenFileDialog1.FileName
End If
Me.TextBox1.Text = fName
GetData(fName, DataGridView1, True)
End Sub
Private Sub GetData(ByVal Path As String, ByRef DG As DataGridView, Optional ByVal NoHeader As Boolean = False)
Dim Fields() As String
Dim Start As Integer = 1
If NoHeader Then Start = 0
If Not File.Exists(Path) Then
Return
End If
Dim Lines() As String = File.ReadAllLines(Path)
Lines(0) = Lines(0).Replace(Chr(34), "")
Fields = Lines(0).Split(",")
If NoHeader Then
For I = 1 To Fields.Count - 1
Fields(I) = Str(I)
Next
End If
For Each Header As String In Fields
DG.Columns.Add(Header, Header)
Next
For I = Start To Lines.Count - 1
Lines(I) = Lines(I).Replace(Chr(34), "")
Fields = Lines(I).Split(",")
DG.Rows.Add(Fields)
Next
End Sub
I just want to be able to filter say column 5 (no column headers in csv file) by typing something in textbox2. Any help would be greatly appreciated. Thank you

Answer 1

Don't add the values to a DGV, but instead use a DataTable then just make a query on that. Example considers you have a combobox for some filter choices - they are other ways to get this to depending on your needs. This method requires you to have headers though.
Private dt As New DataTable
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim fName As String = ""
OpenFileDialog1.InitialDirectory = "C:\"
OpenFileDialog1.Filter = "CSV Files (*.csv)|*.csv"
OpenFileDialog1.FilterIndex = 2
OpenFileDialog1.RestoreDirectory = True
If (OpenFileDialog1.ShowDialog() = Windows.Forms.DialogResult.OK) Then
fName = OpenFileDialog1.FileName
End If
Me.TextBox1.Text = fName
LoadData(fName)
FilterData(combobox1.Text, "some column name")
End Sub
Private Sub LoadData(ByVal Path As String)
Dim Fields() As String
Dim Start As Integer = 1
If NoHeader Then Start = 0
If Not File.Exists(Path) Then
Return
End If
Dim Lines() As String = File.ReadAllLines(Path)
Lines(0) = Lines(0).Replace(Chr(34), "")
Fields = Lines(0).Split(",")
For I = 1 To Fields.Count - 1
Fields(I) = Str(I)
Next
For Each Header As String In Fields
dt.Columns.Add(Header, Header)
Next
For I = Start To Lines.Count - 1
Lines(I) = Lines(I).Replace(Chr(34), "")
Fields = Lines(I).Split(",")
dt.Rows.Add(Fields)
Next
End Sub
Private Sub FilterData(filter As String, columnName as string)
Dim query = From dr As DataRow In dt.Rows Where dr(columnName).ToString = filter
DGV.DataSource = query
End Sub