ClosedXML can't delete file after saving Workbook "process in use" - runtime-error

Question

So here's the code:
string filename = #"c:\test.xlsx";
using (XLWorkbook wb = CreateWorkbookInformation())
{
wb.SaveAs(filename);
Email.EmailAsAttachment(filename);
}
File.Delete(filename);
It creates the Workbook information just fine, it saves the file fine, it emails the file fine as an attachment... However, when I try to delete file (after the using statement), it states the "process is in use". There shouldn't be anything keeping the file open?!? What process am I missing that I should close in order to delete the file?

Answer 1

Ahh, nevermind, had nothing to do with ClosedXML, had everything to do with attaching the file to the email and not using a proper usingstatement for the attachment. So the attachment process was keeping the file open.

Answer 2

Thank you so much for posting this answer!!!
I went crazy trying to understand what's my problem!
I did as you suggested and used the proper using statement:
using (MailMessage mail = new MailMessage(senderAdress, emailAdress))
{
SmtpClient client = new SmtpClient();
client.Port = 25;
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.UseDefaultCredentials = false;
client.Host = ConfigurationManager.AppSettings["SMTPHostName"];
if (string.IsNullOrWhiteSpace(client.Host))
{
errorMsg = "ConfigurationManager.AppSettings[\"SMTPHostName\"] not found";
return false;
}
mail.Subject = subject;
mail.IsBodyHtml = isBodyHtml;
mail.Body = body;
if (!string.IsNullOrWhiteSpace(attachmentFullPath))
{
if (File.Exists(attachmentFullPath))
{
System.Net.Mime.ContentType contentType = new System.Net.Mime.ContentType();
contentType.MediaType = System.Net.Mime.MediaTypeNames.Application.Octet;
contentType.Name = Path.GetFileName(attachmentFullPath);
mail.Attachments.Add(new Attachment(attachmentFullPath, contentType));
}
else
{
errorMsg = "Attachment File Doesn't Exist: " + attachmentFullPath;
return false;
}
}
client.Send(mail);
}