Private Sub Form1_Paint(...) Handles Me.Paint
    ' Find cell (1, 2).
    Dim rect As Rectangle = _
        DataGridView1.GetCellDisplayRectangle(1, 1, False)
    Dim x1 As Integer = DataGridView1.Left
    Dim y1 As Integer = DataGridView1.Top
    Dim the_pen As Pen
    If DataGridView1.Rows(1).Cells(1).Displayed Then
        the_pen = Pens.Blue
    Else
        the_pen = Pens.Red
    End If
    e.Graphics.DrawLine(the_pen, 0, y1 + rect.Top, _
        Me.ClientSize.Width, y1 + rect.Top)
    e.Graphics.DrawLine(the_pen, 0, y1 + rect.Bottom, _
        Me.ClientSize.Width, y1 + rect.Bottom)
    e.Graphics.DrawLine(the_pen, x1 + rect.Left, 0, x1 + _
        rect.Left, Me.ClientSize.Height)
    e.Graphics.DrawLine(the_pen, x1 + rect.Right, 0, x1 + _
        rect.Right, Me.ClientSize.Height)
End Sub

Private Sub DataGridView1_ColumnWidthChanged(...) Handles _
    DataGridView1.ColumnWidthChanged
    Me.Invalidate()
End Sub
Private Sub DataGridView1_RowHeightChanged(...) Handles _
    DataGridView1.RowHeightChanged
    Me.Invalidate()
End Sub
Private Sub DataGridView1_Scroll(...) Handles _
    DataGridView1.Scroll
    Me.Invalidate()
End Sub