I have developed a web based application in ASP.NET and C# where users have the facility to upload files on the server through this application I want the application to Scan th
First of all the file must be saved onto the server before you can scan it. If you notice Yahoo will upload the file first - but not allow the attachment to be sent until scanned.
Then you can use an antivirus with a command line interface or some other kind of API. Both of these can be called via C# and should provide the functionality you require. Parhaps write a wrapper class that takes a file and returns true or false depending on whether a virus was detected.