Vb.net Billing Software Source Code Page

' Add to DataGridView (cart) dgvCart.Rows.Add( row("ProductID"), row("ProductName"), qty, row("UnitPrice"), row("GST_Percent"), qty * Convert.ToDecimal(row("UnitPrice")) )

offers a practical, customizable foundation for desktop invoicing systems. Whether you run a retail store, a wholesale distributor, or a service center, VB.NET gives you full control over your billing logic, tax calculations, and reporting—without recurring subscription fees.

Private Sub btnCustomers_Click(sender As Object, e As EventArgs) Handles btnCustomers.Click Dim customers As New frmCustomers() customers.ShowDialog() End Sub

Private Sub btnAddItem_Click(sender As Object, e As EventArgs) Handles btnAddItem.Click ' Assume txtProductCode, txtQuantity, dgvCart are controls Dim productCode As String = txtProductCode.Text.Trim Dim qty As Integer = Integer.Parse(txtQuantity.Text) ' Fetch product from DB Dim cmd As New SqlCommand("SELECT ProductID, ProductName, UnitPrice, GST_Percent, StockQuantity FROM tbl_Product WHERE ProductCode=@code", con) cmd.Parameters.AddWithValue("@code", productCode) Dim da As New SqlDataAdapter(cmd) Dim dt As New DataTable da.Fill(dt)

Modern alternatives include C# WPF, .NET MAUI, or web-based systems, but VB.NET wins for: vb.net billing software source code

Public Class Product Public Property ProductID As Integer Public Property ProductCode As String Public Property ProductName As String Public Property Category As String Public Property UnitPrice As Decimal Public Property StockQuantity As Integer Public Property GSTPercentage As Decimal Public Function AddProduct() As Boolean Try Dim query As String = "INSERT INTO Products (ProductCode, ProductName, Category, UnitPrice, StockQuantity, GSTPercentage) VALUES (@Code, @Name, @Category, @Price, @Stock, @GST)" DBConnection.OpenConnection() Using cmd As New SqlCommand(query, DBConnection.conn) cmd.Parameters.AddWithValue("@Code", ProductCode) cmd.Parameters.AddWithValue("@Name", ProductName) cmd.Parameters.AddWithValue("@Category", Category) cmd.Parameters.AddWithValue("@Price", UnitPrice) cmd.Parameters.AddWithValue("@Stock", StockQuantity) cmd.Parameters.AddWithValue("@GST", GSTPercentage) Return cmd.ExecuteNonQuery() > 0 End Using Catch ex As Exception MessageBox.Show("Error: " & ex.Message) Return False Finally DBConnection.CloseConnection() End Try End Function

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A professional billing software source code package should include at least these modules:

-- Invoice Header CREATE TABLE tbl_Invoice ( InvoiceNo INT PRIMARY KEY IDENTITY(1,1), InvoiceDate DATETIME DEFAULT GETDATE(), CustomerID INT FOREIGN KEY REFERENCES tbl_Customer(CustomerID), SubTotal DECIMAL(18,2), GST_Amount DECIMAL(18,2), GrandTotal DECIMAL(18,2), PaymentMode NVARCHAR(20) -- Cash/Card/UPI ); ' Add to DataGridView (cart) dgvCart

"The lack of a layered architecture makes the application brittle. For example, if the database schema changes, modifications are required directly in the UI event handlers (e.g., BtnSave_Click ), violating the Open/Closed Principle."

: For more advanced needs, SourceForge hosts pure VB.NET source code for POS and inventory management compatible with SQL Server.

This article provides a comprehensive overview of building, utilizing, and understanding VB.NET billing software source code, covering key features, architectural design, and implementation strategies. 1. Why Use VB.NET for Billing Software?

| Module | Description | |--------|-------------| | | Product, Customer, User, Tax (GST/VAT), Company Profile | | Transaction (Billing) | Create/Edit/Print Invoice, Add/Remove Items, Auto-calc totals | | Inventory | Stock-in, Stock-out, Low stock alerts | | Reports | Daily Sales, GST Summary, Customer Ledger, Profit/Loss | | Backup & Security | Database backup, User login, Role-based access | For example, if the database schema changes, modifications

Manages interaction with databases—commonly SQL Server or Microsoft Access—using ADO.NET for CRUD (Create, Read, Update, Delete) operations. Key Components of the Source Code

Public Class DBConnection Private Shared connectionString As String = "Data Source=localhost;Initial Catalog=BillingSystem;Integrated Security=True" Public Shared conn As SqlConnection = New SqlConnection(connectionString)

Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click If ValidateFields() Then Dim product As New Product() product.ProductCode = txtProductCode.Text product.ProductName = txtProductName.Text product.Category = txtCategory.Text product.UnitPrice = Decimal.Parse(txtPrice.Text) product.StockQuantity = Integer.Parse(txtStock.Text) product.GSTPercentage = Decimal.Parse(txtGST.Text)

Add key bindings so users don't have to reach for a mouse during checkout. For instance, tie F5 to trigger the invoice save event and F2 to move focus straight back to the Product Code entry field.

--- ## 5. Critical Engineering Principles Applied ### Acid-Compliant Transactions The saving mechanism utilizes `SqlTransaction`. This guarantees that if any operation fails midway—such as an out-of-stock database restriction or network failure during row insertion—the entire database transaction rolls back. This prevents orphaned records where a customer is charged but the items fail to register. ### Automated Inventory Deduction When line items are finalized, the system updates the inventory levels inside the `Products` table using atomic SQL operations (`StockQuantity = StockQuantity - @Qty`). This prevents synchronization issues across concurrent point-of-sale stations. ### Input Sanitization and Parametric Queries The source code completely eliminates SQL injection vulnerabilities by abandoning string concatenation in favor of strict typed mapping using `SqlCommand.Parameters.AddWithValue`. --- ## 6. Expanding the System To scale this foundational template up to an enterprise-grade product, consider integrating these advanced features: * **Reporting Module**: Add Crystal Reports or Microsoft Report Viewer (RDLC) to output physical, printable PDFs. * **Barcode Scanner Integration**: Program the text entry systems to instantly match raw string inputs from commercial USB or Bluetooth barcode scanning hardware. * **Asynchronous Database Calls**: Update standard `ExecuteNonQuery` calls to `ExecuteNonQueryAsync` to keep the UI completely responsive during heavy enterprise transactions. If you would like to expand this system further, Share public link