how can i auto sum the values in datagrid cells of the same row in vb.net

How do you populate your datagrid?

Let's imagine population is done so there is code, product, units, price, discount and amount.
Probably you'll need to calculate the amount by clicking the 'update amount' button:

    Private Sub DataGrid_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        DataGridView1.ColumnCount = 6
        DataGridView1.Columns(0).Name = "Code"
        DataGridView1.Columns(1).Name = "Product"
        DataGridView1.Columns(2).Name = "Units"
        DataGridView1.Columns(3).Name = "Price"
        DataGridView1.Columns(4).Name = "Discount"
        DataGridView1.Columns(5).Name = "Amount"

        Dim row As String()
        row = New String() {"3", "Product A", "100", "5.5", "0.0", "0"}
        DataGridView1.Rows.Add(row)
        row = New String() {"5", "Product B", "20", "15.0", "3.0", "0"}
        DataGridView1.Rows.Add(row)
        row = New String() {"6", "Product C", "300", "2.5", "5.0", "0"}
        DataGridView1.Rows.Add(row)
        row = New String() {"8", "Product D", "70", "10", "0.0", "0"}
        DataGridView1.Rows.Add(row)
        DataGridView1.Columns(0).Visible = False

        Dim btn As New DataGridViewButtonColumn()
        DataGridView1.Columns.Add(btn)
        btn.HeaderText = "Update"
        btn.Text = "Update Amount"
        btn.Name = "btnUpdate"
        btn.UseColumnTextForButtonValue = True

    End Sub
    Function parseNum(value As String) As Double
        Static us As New Globalization.CultureInfo("en-US")
        Dim dbl As Double
        Double.TryParse(value, _
            Globalization.NumberStyles.Any, us, dbl)
        Return dbl
    End Function
    Dim us As New Globalization.CultureInfo("en-US")
    Private Sub DataGridView1_CellClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellClick
        Try
            With DataGridView1
                If .Columns(e.ColumnIndex).Name = "btnUpdate" Then ' update button pressed
                    Dim units, price, discount, amount As Double
                    Dim colAmount As Int32
                    For i = 0 To .Columns.Count - 1
                        Dim value = .Rows(e.RowIndex).Cells(i).Value
                        Select Case LCase(.Columns(i).Name)
                            Case "units" : units = parseNum(value)
                            Case "price" : price = parseNum(value)
                            Case "discount" : discount = parseNum(value)
                            Case "amount" : colAmount = i
                        End Select
                    Next
                    amount = units * price * (1 - discount / 100.0)
                    .Rows(e.RowIndex).Cells(colAmount).Value = amount.ToString(us)
                End If
            End With
        Catch ex As Exception

        End Try
    End Sub
commented: Nice! +15