How to draw images in one computer and propagate them?

Question

I am developing a web application where users can draw their own images in a web page using canvas. After it's drawn, this image should be shown in other users' browsers' canvas. Same thing with updates.

I am only using javascript. How can i solve this problem using System.net and Asp.net?

Answer 1

You should look at using long-running AJAX calls to "push" the updates from the server to the clients. This is commonly referred to as the Comet web application model.

http://en.wikipedia.org/wiki/Comet_(programming)

If HTML5 is an option, web sockets could be used to support updates more efficiently than long running AJAX calls.

http://en.wikipedia.org/wiki/Web_Sockets

Regardless of the method, finding a good web server that can handle long running requests will be important, if scalability is a concern. Look for a web server that has a small allocation per connection and that doesn't assign an OS thread per connection like node.js

http://nodejs.org/#about