Question

当我尝试删除“foreach”循环中的文件时，我收到了错误消息。

我知道我需要在某个地方使用关键字'using`，但我不知道在哪里以及如何。

private void btnEmailIntegrationFiles_Click(object sender, EventArgs e)
{
    DialogResult EmailWarningMsg = MessageBox.Show("You're about to email the Integration IAT text files. Are you sure?", "WARNING!", MessageBoxButtons.YesNo, MessageBoxIcon.Warning, MessageBoxDefaultButton.Button2);

    if (EmailWarningMsg == DialogResult.Yes)
    {
        if (Directory.GetFiles(AppVars.NetworkIntegrationFileLocation).Length == 0)
        {
            MessageBox.Show("The folder is empty. Please create the files before sending it.", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
        else
        {
            if (Directory.GetFiles(AppVars.NetworkIntegrationFileLocation).Length != 4)
            {
                MessageBox.Show("The folder does not contain exactly 4 files.", "Error!", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
            else
            {
                Email email = new Email();

                email.SendEmailToFinalDestinationWithAttachments(AppVars.DBTeamEmail, AppVars.ChrisWhitmoreEmail, AppVars.DBTeamEmail, "Integration Files", "Please see integration files attached.");
            }
        }

        PopulateListViewWithPoliciesAvailableToHoldBack();

        string[] files = Directory.GetFiles(AppVars.NetworkIntegrationFileLocation);

        foreach (string file in files)
        {
            File.Delete(file);
        }
    }
}

如何使用关键字using进行“电子邮件发送”，以便在尝试删除以附件形式通过电子邮件发送的文件时，我不会遇到此错误消息？

这是发送电子邮件类：

public void SendEmailToFinalDestinationWithAttachments(string EmailFrom, string EmailTo, string EmailCC, string EmailSubject, string EmailBody)
        {
            try
            {
                MailMessage EmailMessage = new MailMessage();
                SmtpClient smtp = new SmtpClient(AppVars.SMTPClient, AppVars.SMTPClientPort);
                smtp.UseDefaultCredentials = false;
                EmailMessage.IsBodyHtml = true;
                EmailMessage.To.Add(EmailTo);
                EmailMessage.CC.Add(EmailCC);
                EmailMessage.CC.Add(user);
                EmailMessage.Subject = EmailSubject;
                EmailMessage.From = new MailAddress(EmailFrom);
                EmailMessage.Body = EmailBody;

                string[] files = Directory.GetFiles(AppVars.NetworkIntegrationFileLocation, "*" + DateTime.Now.ToString("yyyyMMdd") + "*");

                foreach (string file in files)
                {
                    EmailMessage.Attachments.Add(new Attachment(file));
                }

                smtp.Send(EmailMessage);
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message);
            }
        }

Answer 1

您需要将您的EMail类修改为：

using (MailMessage EmailMessage = new MailMessage()) {
    ...
    smtp.Send(EmailMessage);
}

无法删除文件，因为它正被另一个进程使用

1 个答案: