Filtering binding source - vb.net

Question

This should be easy but I am having a headbanging of a time trying to get this to work! I have done a search and tried all most EVERY SINGLE ONE. Nothing works. I have a datagrid with a binding source. A user will type text into a textbox and the grid is SUPPOSED to change to only show records that contain what user typed in the name. Simple right? NOPE! Not for me! What am I doing wrong? Code below.
Private Sub SearchButton_Click(sender As Object, e As EventArgs) Handles SearchButton.Click
Dim Found As Boolean = False
Dim StringToSearch As String = ""
Dim ValueToSearchFor As String = "%" & SearchTextBox.Text.Trim.ToLower & "%"
Dim CurrentRowIndex As Integer = 0
Try
If ReferencesGrid.Rows.Count = 0 Then
CurrentRowIndex = 0
Else
CurrentRowIndex = ReferencesGrid.CurrentRow.Index + 1
End If
If CurrentRowIndex > ReferencesGrid.Rows.Count Then
CurrentRowIndex = ReferencesGrid.Rows.Count - 1
End If
If ReferencesGrid.Rows.Count > 0 Then
For Each gRow As DataGridViewRow In ReferencesGrid.Rows
StringToSearch = gRow.Cells(1).Value.ToString.Trim.ToLower
If InStr(1, StringToSearch, LCase(Trim(SearchTextBox.Text)), vbTextCompare) Then
TrainingItemBindingSource.Filter = String.Format("Name LIKE '{0}'", ValueToSearchFor)
Exit For
End If
Next
End If
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub

Answer 1

You should get rid of pretty much all that code. If you want to filter the data then just filter the data. There's no conditional statements required and loops required. Just set the Filter property and any records that don't match the filter will be hidden:
Private Sub SearchButton_Click(sender As Object, e As EventArgs) Handles SearchButton.Click
TrainingItemBindingSource.Filter = $"Name LIKE '%{SearchTextBox.Text.Trim()}%'"
End Sub
As you can see, it is simple. I've no real idea what you were actually trying to achieve with the rest of that code. That will exclude any records where the Name column does not contain the search text.
Note that there is no need to try to force case-insensitivity by using ToLower or the like. Just like in real SQL, comparisons done this way in a DataTable are case-insensitive by default. You have to explicitly set the CaseSensitive property of the DataTable or its parent DataSet to True to make such comparisons case-sensitive.
I should also point out that the ability to filter is predicated on the data source implementing certain interfaces. If the data source is a DataTable then you have those interfaces for free. If you have actually bound to something else, e.g. a List(Of T), then you won't be able to filter this way because the required members do not exist.