.NET-based Simple Billing Software

Revised Draft for Freelance Developer Requirement Project Title: Simple Billing Application (Windows Forms) Project Overview This is a simple desktop billing application to be developed using Windows Forms in .NET Framework. The application allows a salesperson to create invoices by entering product details such as MRP, discounted price, and quantity. It will automatically calculate the total payable amount and savings for the customer. The application will also allow the user to print invoices on an Epson TM-T82 (3-inch roll) thermal printer. This project is very simple, focusing on core billing functionalities with minimal complexity. Technology Stack Backend: .NET Framework (Windows Forms Application). Frontend: Windows Forms (UI). Database: SQL Server or SQLite (lightweight for local storage). Features Add Invoice Items: Enter MRP, discounted price, and quantity for each product. Automatic Calculations: Calculate total payable amount and savings for the customer. Optional Customer Mobile Number: Enter the mobile number only at the final stage (optional). Edit Invoice: Edit or remove items before finalizing. Finalize Invoice: Generate the final invoice with customer details. Print Invoice: Send the invoice details to an Epson TM-T82 thermal printer. Database Design Tables Invoices Table InvoiceID (Primary Key, Auto-increment) InvoiceDateTime (Date and time of the invoice generation, auto-generated) TotalAmount (Total payable amount for the invoice) TotalSavings (Total savings for the customer) CustomerMobile (Optional, the customer’s mobile number) InvoiceItems Table InvoiceItemID (Primary Key, Auto-increment) InvoiceID (Foreign Key referencing Invoices) MRP (Maximum Retail Price for the product) DiscountedPrice (Discounted price per unit) Quantity (Quantity of the product sold) Savings (Calculated as (MRP - DiscountedPrice) * Quantity) Application Pages / Forms Home Form (Main Form) Displays a button to start a new invoice. View previous invoices (optional, depending on scope). Add Invoice Items Form A simple form where the user can add invoice items: Input fields: MRP, Discounted Price, Quantity. A data grid or list to display added items. A button to add items to the list. Invoice Summary Form A form to show all added items with total amount and total savings. The user can edit or remove items before finalizing. Option to enter a customer mobile number (optional). A button to finalize the invoice and generate the total. Finalize Invoice Form Display total invoice amount and customer savings. Option to enter the customer’s mobile number. A "Finalize" button to generate the invoice. Invoice Printing The final invoice will be sent to the Epson TM-T82 thermal printer for printing. The printer layout will include: Date and time of invoice. List of products (MRP, quantity, discounted price, savings). Total payable amount and customer savings. Optional customer mobile number. Business Logic Invoice Calculations Total Amount: Sum of (DiscountedPrice * Quantity) for all items. Total Savings: Sum of (MRP - DiscountedPrice) * Quantity for all items. Invoice Finalization After entering invoice details, the user can confirm and print the invoice. The final invoice will include: Invoice date and time. List of added items (MRP, quantity, discounted price, savings). Total amount payable and total savings. Optional customer mobile number. Printer Integration The application should integrate with the Epson TM-T82 (3-inch roll) thermal printer. Ensure the invoice content fits within the printer’s dimensions, and the printing should align correctly. Deliverables Full Windows Forms Application using .NET Framework. Database Schema for Invoices and InvoiceItems tables. Invoice Print Layout and integration with Epson TM-T82 thermal printer. Source code and installation instructions. Additional Notes The application should be lightweight and easy to use, with clear fields for entering item details and a simple form for editing invoices. Customer mobile number is optional and only entered at the time of finalizing the invoice. The application does not require advanced features like user authentication, inventory management, or product catalog. The print layout should be designed to fit a 3-inch thermal roll. Timeline The application is simple and should be completed within 2 working days, including testing and debugging.