NullReference error on file upload

Question

User1216627406 posted

Greetings again,

I am getting the following error when attempting to email an uploaded file:

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

A brief history:

We use a script (we got from aspsnippets.com).

This script allows you to attach multiple files. In my example, I was able to attach three files successfully.

Then I click Submit to send the attached files via email to user

However, when I click to Submit, I am getting the NullReferencException error.

I can confirm that when I check the Uploads folder where the files were stored, they are there.

I am not sure what the issue is.

Here is just relevant code that I am using:

//HTML

	                 <table style="width:90%;border:0; margin:auto;padding:10px;text-align:center;border-spacing:0;">
                      <tr>
                        <td colspan="3">&nbsp;</td>
                      </tr>
                      <tr>
                      <td colspan="2"></td>
                       <td><strong>File Attachments: </strong>
                       <asp:FileUpload ID="FileUpload1" runat="server" /></td>
                      </tr>
                      <tr>
                      <td></td>
                       <td>
                       <table id = "attachedfiles"></table>
                       </td>
                     </tr>
                    </table>	

//VB:

                Dim msg As MailMessage = New MailMessage()
                Dim address As MailAddress = New MailAddress("[e-mail]")
                msg.To.Add(address)
                msg.From = New MailAddress(email.Text.ToString())
                msg.Subject = "Job Application from " & lblfname.Text & " " & lblmname.Text & " " & lbllname.Text
                msg.Body = "Employment Application From " & lblfname.Text & "&nbsp;" & lblmname.Text & "&nbsp;" & lbllname.Text & "<br />Sent at:" & DateTime.Now & " <br />"
                msg.Attachments.Add(New Attachment(New MemoryStream(bytes), lblfname.Text & "&nbsp;" & lblmname.Text & "&nbsp;" & lbllname.Text & DateTime.Now.Ticks & ".pdf"))
                Dim files As List(Of HttpPostedFile) = DirectCast(Cache(Me.Key), List(Of HttpPostedFile))
                For Each file As HttpPostedFile In files
                    msg.Attachments.Add(New Attachment(file.InputStream, Path.GetFileName(file.FileName), file.ContentType))
                Next
                msg.IsBodyHtml = True
                Dim smtp As New SmtpClient()
                Dim client As SmtpClient = New SmtpClient()
                client.Host = "111.11.111.111"
                smtp.UseDefaultCredentials = False
                'smtp.Credentials = NetworkCred
                smtp.Port = 25
                client.Send(msg)

Any ideas what I am doing wrong?

Thanks in advance

Answer 1

User1120430333 posted

Well, you have to debug the code with the debugger and single-step the until it hits the line of code that is throwing the exception. The error message means thae code is trying to reference/use an object that is a null valued object that is not in memory. You need to find out why.

OO is OO Java or .NET

https://alfredjava.wordpress.com/2008/07/08/class-vs-object-vs-instance/

Answer 2

User409696431 posted
You need to look at what is null. You haven't said what code line, what value is null.