.Net Core之发送邮件

.Net Core之发送邮件

发送邮件是一个通用功能，这里我们使用MailKit配合Polly做重试

封装EmailSender

• IEmailSender

  public interface IEmailSender
  {
      Task SendEmailAsync(string to, string subject, string message, TextFormat textFormat = TextFormat.Plain);
  
      Task SendEmailAsync(List<string> to, string subject, string message, TextFormat textFormat = TextFormat.Plain);
      
      Task SendEmailAsync(string to, string subject, BodyBuilder bodyBuilder);
  
      Task SendEmailAsync(List<string> to, string subject, BodyBuilder bodyBuilder);
  }
  

• EmailSender

  public class EmailSender : IEmailSender
  {
      private readonly EmailSettings _emailSettings;
      private readonly ILogger _logger;
  
      public EmailSender(IOptions<EmailSettings> emailSettings, ILogger<EmailSender> logger)
      {
          _emailSettings = emailSettings.Value;
          _logger = logger;
      }
  
      /// <summary>
      /// 发送邮件
      /// </summary>
      /// <param name="to">接收邮箱(批量)</param>
      /// <param name="subject">主题</param>
      /// <param name="bodyBuilder">内容</param>
      /// <returns></returns>
      public async Task SendEmailAsync(List<string> to, string subject, BodyBuilder bodyBuilder)
      {
          //三次重试机制
          var retryPolicy = Policy.Handle<Exception>().RetryAsync(3,
              (exception, retryCount, context) =>
              {
                  _logger?.LogError("retryCount" + retryCount + ":" + exception);
              });
          try
          {
              var mimeMessage = new MimeMessage();
              mimeMessage.From.Add(new MailboxAddress(_emailSettings.MailSenderName, _emailSettings.MailSender));
              mimeMessage.To.AddRange(to.Select(e => new MailboxAddress(e)));
              mimeMessage.Subject = subject;
              mimeMessage.Body = bodyBuilder.ToMessageBody();
  
              await retryPolicy.ExecuteAndCaptureAsync(async () =>
              {
                  using (var client = new SmtpClient())
                  {
                      // accept all SSL certificates (in case the server supports STARTTLS)
                      client.ServerCertificateValidationCallback = (s, c, h, e) => true;
  
                      await client.ConnectAsync(_emailSettings.MailServer, _emailSettings.MailPort, true);
  
                      await client.AuthenticateAsync(_emailSettings.MailSender, _emailSettings.MailPassword);
  
                      await client.SendAsync(mimeMessage);
  
                      await client.DisconnectAsync(true);
                  }
              });
          }
          catch (Exception ex)
          {
              _logger?.LogError("SendEmailAsync:", ex);
          }
      }
  
      /// <summary>
      /// 发送邮件
      /// </summary>
      /// <param name="to">接收邮箱(单个)</param>
      /// <param name="subject">主题</param>
      /// <param name="bodyBuilder">内容</param>
      /// <returns></returns>
      public async Task SendEmailAsync(string to, string subject, BodyBuilder bodyBuilder)
      {
          await SendEmailAsync(new List<string>() { to }, subject, bodyBuilder);
      }
  
      /// <summary>
      /// 发送邮件
      /// </summary>
      /// <param name="to">接收邮箱(单个)</param>
      /// <param name="subject">主题</param>
      /// <param name="message">内容</param>
      /// <param name="textFormat">文本格式</param>
      /// <returns></returns>
      public async Task SendEmailAsync(string to, string subject, string message,
          TextFormat textFormat = TextFormat.Plain)
      {
          await SendEmailAsync(new List<string>() { to }, subject, message, textFormat);
      }
  
      /// <summary>
      /// 发送邮件
      /// </summary>
      /// <param name="to">接收邮箱(可多个)</param>
      /// <param name="subject">主题</param>
      /// <param name="message">内容</param>
      /// <param name="textFormat">文本格式</param>
      /// <returns></returns>
      public async Task SendEmailAsync(List<string> to, string subject, string message,
          TextFormat textFormat = TextFormat.Plain)
      {
          var bodyBuilder = new BodyBuilder();
          switch (textFormat)
          {
              case TextFormat.Html:
                  bodyBuilder.HtmlBody = message;
                  break;
              default:
                  bodyBuilder.TextBody = message;
                  break;
          }
  
          await SendEmailAsync(to, subject, bodyBuilder);
      }
  }
  

  折叠

• 注入

  services.AddSingleton<IEmailSender, EmailSender>();
  

• 使用

  发送邮件常用到html格式和附件，这里用到了html表格和excel附件

  /// <summary>
  /// DataTable转为Html表格字符
  /// </summary>
  /// <param name="dt"></param>
  /// <returns></returns>
  public static string FormatHtmlTable(DataTable dt)
  {
      var sb = new StringBuilder();
      //开始
      sb.Append(
          "<table cellpadding='5' cellspacing='0' style='border: 1px solid #ccc;font-size: 9pt;font-family:Arial'>");
  
      //表头
      sb.Append("<tr>");
      foreach (DataColumn column in dt.Columns)
      {
          sb.Append($"<th style='border: 1px solid #ccc'>{column.ColumnName}</th>");
      }
  
      sb.Append("</tr>");
  
      //数据
      foreach (DataRow row in dt.Rows)
      {
          sb.Append("<tr>");
          foreach (DataColumn column in dt.Columns)
          {
              sb.Append($"<td style='width:100px;border: 1px solid #ccc'>{row[column.ColumnName]}</td>");
          }
  
          sb.Append("</tr>");
      }
  
      //结束
      sb.Append("</table>");
      return sb.ToString();
  }
  

  折叠

  //自定义BodyBuilder，使用html表格和附件
  var bodyBuilder = new BodyBuilder();
  //html
  var table = new DataTable();
  var tableHtml = HtmlUtils.FormatHtmlTable(table);
  bodyBuilder.HtmlBody = tableHtml;
  //附件
  bodyBuilder.Attachments.Add($"附件.xlsx",byte[]data);
  
  await emailSender.SendEmailAsync(email, emailSubject, bodyBuilder);

转 https://www.cnblogs.com/shadowxs/p/14291012.html