C#

ImporterCollection importerCollection = new ImporterCollection();

public FormManageImporters()
{
    InitializeComponent();
    LoadImporters();
    SetDataset();
    SetBindings();
}

private void LoadImporters()
{
    importerCollection.FillImporters();
}

private void SetDataset()
{
    listBoxImporters.DataSource = importerCollection;
    listBoxImporters.ValueMember = "ImporterID";
    listBoxImporters.DisplayMember = "ImporterName";
}

private void SetBindings()
{
    textBoxPhone.DataBindings.Add("Text", importerCollection, "Phone");
    textBoxAlternativePhone.DataBindings.Add("Text", importerCollection, "AlternativePhone");
    textBoxCellularPhone.DataBindings.Add("Text", importerCollection, "CellularPhone");
    textBoxFax.DataBindings.Add("Text", importerCollection, "Fax");
}

private void Importer_Changed(object sender, EventArgs e)
{
    LoadImporters();
}

private void buttonAdd_Click(object sender, EventArgs e)
{
    FormImporter formImporter = new FormImporter();
    formImporter.ImporterChanged += new FormImporter.ImporterChangedEventHandler(Importer_Changed);
    formImporter.Show();
}

double price = 0.0;
foreach (DataGridViewRow dgw in dataGridProduct.Rows)
{
    DataGridViewCheckBoxCell datacell = dgw.Cells[0] as DataGridViewCheckBoxCell;

    try
    {
        if ((bool)datacell.Value == true)
        {
            //MessageBox.Show("" + dgw.ToString());

            price += Convert.ToDouble(dgw.Cells[6].Value.ToString());
            lblTotalPrice.Text = "Total Price : $ " + price;
        }
    }
    catch (Exception exc)
    {
    }
}