sendgrid 从 C# Winform App 发送到电子邮件列表

Question

我有一个 Winform 应用程序，我想从中发送电子邮件，我可以使用 sendgrid 并输入电子邮件地址来完成。问题是我要发送的电子邮件会根据情况发送给不同的人，因此“to field”需要是动态的。

我有一个 SQL 数据库，用于存储人们希望收到通知的事件的电子邮件地址，我在准备发送电子邮件时拉出该列表，但我不知道如何将这些项目放入 @987654321 的列表中@Sendgrid 想要的。

            try
        {
            using (SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["MfgDataCollector"].ToString()))
            {
                var apiKey = "SendGrid Key";
                var client = new SendGridClient(apiKey);
                var from = new EmailAddress("test@gmail.com", "test from App");

                //Standard Email lists
                //var tos = new List<EmailAddress>
                //{
                //new EmailAddress("test@gmail.com"),
                //new EmailAddress("test2@gmail.com")
                //};

                //Query to get emails from SQL using Dapper
                DynamicParameters param = new DynamicParameters();
                param.Add("@Zone", Variables.Zone);
                param.Add("@Gatelevel", Lbl_GateLevel.Text);
                List<AlertMessages> EmailList = conn.Query<AlertMessages>("GetEmailList", param, commandType: CommandType.StoredProcedure).ToList<AlertMessages>();

                //Lost here??? Not sure how to get EmailList to EmailAddresses 
                var tos = new List<EmailAddress> { };

                string subject = txt_Subject.Text;
                string plainTextContent = txt_Body.Text;
                var htmlContent = txt_Body.Text;
                var showAllRecipients = true; // Set to true if you want the recipients to see each others email addresses

                var msg = MailHelper.CreateSingleEmailToMultipleRecipients(from,
                                                                           tos,
                                                                           subject,
                                                                           plainTextContent,
                                                                           htmlContent,
                                                                           showAllRecipients
                                                                           );
                var response = await client.SendEmailAsync(msg);
                MessageBox.Show("SendGrid Completed");
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "Send Email Notification - SendGrid - Oops!", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }

警报消息类

public class AlertMessages
    {
        public int ID { get; set; }
        public string EmailAddress { get; set; }
        public int ZoneID { get; set; }
        public string Zone { get; set; }
        public string GateLevel { get; set; }
        public string Emails { get; set; }
    }

Answer 1

假设您已成功从 Dapper 查询中获取电子邮件列表

List<AlertMessages> EmailList = conn.Query<AlertMessages>("GetEmailList", param, commandType: CommandType.StoredProcedure).ToList<AlertMessages>();

你的AlertMessages 类有string 属性是Email 和Name 喜欢

class AlertMessages
{
    ...
    public string Email { get; set; }
    public string Name { get; set; }
    ...
}

然后你可以将你的List<AlertMessages> 扁平化为List<EmailAddress> 喜欢，

var tos = EmailList.Select(item => new EmailAddress { Email = item.Email, Name = item.Name }).ToList();

其中item 是AlertMessages 类型的选择迭代器变量，item.Email 和item.Name 是各自迭代器变量的属性。

然后将上面的tos列表传递给CreateSingleEmailToMultipleRecipients方法。