使用memorystream将ICS作为邮件附件发送

using System;
using System.IO;
using System.Net.Mail;

class Program
{
    static void Main()
    {
        // 读取ICS文件内容
        string icsFilePath = "path/to/ics/file.ics";
        string icsContent = File.ReadAllText(icsFilePath);

        // 创建内存流
        using (MemoryStream memoryStream = new MemoryStream())
        {
            // 将ICS内容写入内存流
            using (StreamWriter writer = new StreamWriter(memoryStream))
            {
                writer.Write(icsContent);
                writer.Flush();

                // 设置内存流的位置为起始位置
                memoryStream.Position = 0;

                // 创建邮件对象
                MailMessage mail = new MailMessage();
                mail.Subject = "ICS文件邮件附件";
                mail.Body = "请查看附件中的ICS文件。";

                // 将内存流作为附件添加到邮件中
                Attachment attachment = new Attachment(memoryStream, "calendar.ics", "text/calendar");
                mail.Attachments.Add(attachment);

                // 设置邮件发送相关信息
                SmtpClient smtpClient = new SmtpClient("smtp.example.com");
                smtpClient.Credentials = new System.Net.NetworkCredential("username", "password");
                smtpClient.EnableSsl = true;

                // 发送邮件
                smtpClient.Send(mail);
            }
        }
    }
}