Unable to serialize the session state using asyncfileupload.

Error:-

Unable to serialize the session state. In 'StateServer' and 'SQLServer' mode, ASP.NET will serialize the session state objects, and as a result non-serializable objects or MarshalByRef objects are not permitted. The same restriction applies if similar serialization is done by the custom session state store in 'Custom' mode.

Note: I am using State Server mode. and trying to store Control in session:-

if (asyUpldOffer.HasFile)

{

string contentType = asyUpldOffer.ContentType;

if (contentType == "application/vnd.openxmlformats-officedocument.wordprocessingml.document" || contentType == "application/pdf" || contentType == "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" || contentType == "application/msword" || contentType == "image/jpeg" || contentType == "image/jpg")

{

Session["UploadOffer"] = asyUpldOffer;

}

else

{

Session["UploadOffer"] = null;

}

Hi,

I believe "asyUpldOffer" is FileUpload control. It is a WebControl.

WebControls are not serializable so you can not store them in session for sure,.

Also storing FileUpload control in session will not store the content of the file in session.

You retrieve the contents of the file and save it in db or in temporary file location.

Actually you can store the file content in the database as string and the ID of that table row you should store in the session. And then use that ID to get the file from db during your session.

https://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.fileupload.hasfile(v=vs.110).aspx

https://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.fileupload.filecontent(v=vs.110).aspx

Above links will help you to learn how to save file content of FileUpload control in a file.