Private Sub btnAddProduct_Click(sender As Object, e As EventArgs) Handles btnAddProduct.Click ' Assume a popup product search form returns selected product Dim frm As New frmProductSearch() If frm.ShowDialog() = DialogResult.OK Then Dim newRow As DataRow = dtDetails.NewRow() newRow("ProductID") = frm.SelectedProductID newRow("ProductName") = frm.SelectedProductName newRow("Quantity") = 1 newRow("Rate") = frm.Rate ' Tax calculation will be done row-by-row based on GST% Dim gstPercent As Decimal = frm.GSTPercent Dim taxable As Decimal = newRow("Quantity") * newRow("Rate") newRow("TaxableValue") = taxable newRow("CGST") = Math.Round(taxable * (gstPercent / 100) / 2, 2) newRow("SGST") = Math.Round(taxable * (gstPercent / 100) / 2, 2) dtDetails.Rows.Add(newRow) CalculateTotals() End If End Sub
CalculateTotal()
Try Dim totalAmount As Decimal = items.Sum(Function(i) i.Total) Dim invoiceId As Integer vbnet+billing+software+source+code
Creating billing software in VB.NET is an excellent way to understand transaction handling, foreign keys, and real-time calculations. The source code provided above gives you a professional starting point. You can extend it to support multi-currency, discounts, or even cloud sync via Web API. Private Sub btnAddProduct_Click(sender As Object