how to generate Invoice Number on each Bill

Question

I have generated a Bill Generator application without using a database. This application generates bills and saves them with a file name in a folder as an HTML file. Right now I am using a timestamp to generate a unique ID for each bill. Now I want to reduce the length of my ID; I want to use serial number.

Problem: I am using an integer variable and on click I increment the value by one, but when I restart my application, the counter is reset...

How can I save last generated value and pick up where I left off when the application restarts?

Answer 1

Here are some options, depending on your application and needs:

• Use a text file.
• Store the value in a user-scoped Setting.
• Save the value somewhere in the registry.
• Parse the value from the last generated bill and resume where you left off.
• Save the value on your web server and retrieve it when necessary.
• Have your web server or something else persistent always generate the values instead of creating them locally.
• Ask the user to remember the number and enter it the next time.