private void AfterEnterDelete(object sender, KeyEventArgs e)
        {
            if (e.Key != Key.Enter)
            {
                return;
            }
            else
            {
                e.Handled = true;
            }

            if (txtPrice.Text.Length == 0 || txtDelete.Text.Length == 0 || txtUnit.Text.Length == 0)
            {
                return;
            }
            else
            {
                Total         = Double.Parse(txtUnit.Text);
                Deletetotal   = Double.Parse(txtDelete.Text);
                Price         = Double.Parse(txtPrice.Text);
                Total        -= Deletetotal;
                txtTotal.Text = Total.ToString();

                Priceall           = Total * Price;
                txtTotalPrice.Text = Priceall.ToString();
                Total += Deletetotal;
            }
        }
        private void DoubleClickDatagrid(object sender, MouseButtonEventArgs e)
        {
            object item = dataGrid.SelectedItem;

            txtCode.Text  = (dataGrid.SelectedCells[0].Column.GetCellContent(item) as TextBlock).Text;
            txtName.Text  = (dataGrid.SelectedCells[1].Column.GetCellContent(item) as TextBlock).Text;
            txtPrice.Text = (dataGrid.SelectedCells[2].Column.GetCellContent(item) as TextBlock).Text;
            txtType.Text  = (dataGrid.SelectedCells[3].Column.GetCellContent(item) as TextBlock).Text;

            Priceall           = Total * Price;
            txtTotalPrice.Text = Priceall.ToString();
            SearchProduct.Text = "";
        }
        private void UnitEnterTotal(object sender, KeyEventArgs e)
        {
            if (e.Key != Key.Enter)
            {
                return;
            }
            else
            {
                e.Handled = true;
            }

            if (txtDelete.Text == "" || txtPrice.Text == "" || txtUnit.Text == "")
            {
                txtUnit.Text       = "0";
                txtDelete.Text     = "0";
                Total              = Double.Parse(txtUnit.Text);
                Price              = Double.Parse(txtPrice.Text);
                Deletetotal        = Double.Parse(txtDelete.Text);
                Deletetotal        = 0.0;
                txtTotal.Text      = txtUnit.Text;
                Priceall           = Price * Total;
                txtTotalPrice.Text = Priceall.ToString();
                return;
            }
            else
            {
                string[] parts = txtUnit.Text.Split('+');
                Total = 0.0;

                for (int i = 0; i < parts.Length; i++)
                {
                    if (parts[i] == "" || parts[i] == " ")
                    {
                        parts[i] = "0.0";
                    }
                    else
                    {
                        Total += Double.Parse(parts[i]);
                        Total -= Deletetotal;
                    }
                }
                Price              = Double.Parse(txtPrice.Text);
                txtTotal.Text      = Total.ToString();
                Priceall           = Price * Total;
                txtTotalPrice.Text = Priceall.ToString();
                Total             += Deletetotal;
            }
        }