I am using Sharepoint 2010 and created one form using Visual studio,On the page i have used one document uploader control,but when i am submitting the form the attachment has been lost(It's Not being Saved).

Please help me regarding this.

Hi,

Per my understanding, there is a file upload control for attachment uploading in a custom form page which is created in Visual Studio. When the form submitted, the attachment isnt uploaded.

If you want to save the attachment into this list, you will need to implement the file upload method in the code behind, then when the form submitted, the attachment can be uploaded to the list.

Here is a demo about how to use file upload control in SharePoint project for your reference:

http://sharepoint-works.blogspot.com/2012/01/creating-and-deploying-visual-web-part.html#.UjZ91CSwpet