Hi all,

How can i implement folder upload in asp.net using C#?

IF you are asking about a web application uploading from a client, the answer is.

You can't!
Server side code cannot parse the client side folders to create a list of files to upload.

Thanks Chris for your quick reply.

Is it possible with any other technologies like java applets? It would be great help if you suggest any method to implement this.

Theoritically it's possible with a Java applet, provided it is "signed" and the user has allowed elevated permissions to the applet, but this is the kind of operation why browser permissions and clientside access are severely limited.

To be able to accomplish uploading an entire folder from client to server, you would need an "thick client" app running on the client machine with FTP capabilities for uploading.

The only proper way at the moment is to use FTP. You can however hack something together that uses Silverlight and webservices that can upload any size file or folder. You can probably do the same thing using Flash.

Silverlight uses .Net, so if you know .Net, that might be your best solution.

If you are talking about web application,
You cannot upload a folder in a web application. However, after a folder is zipped, it becomes a zip file and can be uploaded.
If you want, a user selects n files and your application should zip it and upload, that's not possible. The user needs to zip the files and upload.
You can unzip the files on the server side using zip applications or may write un-compress algorithm. 7-z[^] is one such open source compression tool.