使用 C# 的电子邮件中的多个附件文件

Multiple attachment file in email using C#

提问by nithi

How to attach the multiple files in an email using c#.

如何使用 c# 在电子邮件中附加多个文件。

        MailMessage mail = new MailMessage();
        SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com");

        //get the userID, Pass
        userID= register.userName;
        password = register.pass;


        string aa=txtTo.Text;
        mail.From = new MailAddress(userID);
        mail.To.Add(aa);
        mail.Subject = txtsubject.Text;
        mail.Body = txtComments.Text;

        //Attach file
        mail.Attachments.Add(new Attachment(txtAttachments.Text.ToString()));       
        SmtpServer.Port = 587;
        SmtpServer.UseDefaultCredentials = false;
        SmtpServer.Credentials = new System.Net.NetworkCredential(userID, password);
        SmtpServer.EnableSsl = true;
        SmtpServer.Send(mail);
        MessageBox.Show("Email sent successfully");
        this.Cursor = Cursors.Default;

        //close the page
        Email email = new Email();
        email.Close();

this code is used for attach one file only. How can i attach multiple files in c# 2008.??? Plz give me the solution.

此代码仅用于附加一个文件。如何在 c# 2008 中附加多个文件。？？？请给我解决方案。

采纳答案by David

...
mail.Body = txtComments.Text;
//Attach file
mail.Attachments.Add(new Attachment(txtAttachments.Text.ToString()));
mail.Attachments.Add(new Attachment(txtAttachments2.Text.ToString()));
mail.Attachments.Add(new Attachment(txtAttachments3.Text.ToString()));
mail.Attachments.Add(new Attachment(txtAttachments4.Text.ToString()));
SmtpServer.Port = 587;
...      

回答by Mitch Wheat

Multiple attachments can be added to the Message.Attachmentscollection

可以将多个附件添加到Message.Attachments集合中

C#:

C＃：

Message.Attachments.Add(new System.Net.Mail.Attachment(strAttPath));

VB:

VB：

Message.Attachments.Add(New Net.Mail.Attachment(strAttPath))

Simply call .Addmultiple times, pointing to each attachment.

只需.Add多次调用，指向每个附件。

回答by phoebus

Just add more attachments to the mail.Attachments collection as you did above.

只需像上面一样向 mail.Attachments 集合中添加更多附件即可。

回答by dpminusa

What about releasing the attachment files after the send?

发送后释放附件怎么办？

For example, you send a temporary file used to create the attachment content. This file is used repetitively for this purpose ongoing. The attachment file will need to be released with a dispose()on the attachment.

例如，您发送一个用于创建附件内容的临时文件。该文件被反复用于此目的。附件文件将需要dispose()在附件上发布。

To accomplish this create the attachment first to give it an object name to use with dispose() later.

要完成此操作，请先创建附件，然后为其指定一个对象名称，以便稍后与 dispose() 一起使用。

Attachment attach = new Attachment(txtAttachments.Text.ToString());    
Message.Attachments.Add(attach);
...

attach.dispose();   

回答by J. Schaefer

protected void SendMail(List<string> attachments)
    {
        UserManagement Users = new UserManagement();
        Users.GetUserInformation();

        SmtpClient client = new SmtpClient(ip_address);
        MailMessage Message = new MailMessage();
        Message.From = new MailAddress(senderaddress);

        Message.To.Add(Users._CurUser_Destination_Email);
        Message.Subject = "Neue Umlagerung - " + cb_auflieger_limburg.SelectedItem.ToString();

        Message.Body = string.Format("Datum: {0}", DateTime.Now) + Environment.NewLine +
                                     "AufliegerNr.: " + cb_auflieger_limburg.SelectedItem.ToString() + Environment.NewLine +
                                     "Benutzer: " + Environment.UserName;

        client.UseDefaultCredentials = true;

        Attachment Attachment = null;

        try
        {
            foreach (string attachment in attachments)
            {
                Attachment = new Attachment(attachment);
                Message.Attachments.Add(Attachment);
            }

            client.Send(Message);
            Attachment.Dispose();
            Message.Dispose();
        }

        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }
        finally
        {
            foreach(string attachment in attachments)
            {
                //Dateien nach Versendung l?schen
                FileInfo fi = new FileInfo(attachment);
                if (fi.Exists)
                {
                    fi.Delete();
                }
            }
        }
    }

The parameter List attachmentsgets filled by a class that exports a DataGridView in different formats like .csv and .pdf

参数列表附件由一个类填充，该类以不同的格式（如 .csv 和 .pdf）导出 DataGridView

The List "atttachments" contains the strings of the folder and filename.

列表“附件”包含文件夹和文件名的字符串。

//Exporting to CSV.
string FileName = $"YourFileName_{datetime}.csv";
File.WriteAllText(ExportPath + FileName, csv);

AttachmentsToExport.Add(ExportPath + FileName);