在电子邮件基础c#中发送gridview

我想创建一个包含gridview的邮件。我一直在网上搜索，并尝试了多种解决方案。但不知何故，我误解或做错了什么。使用我当前的代码，我得到错误:

System.InvalidOperationException: Data source is an invalid type. It must be either 
an IListSource, IEnumerable, or IDataSource. 

我读了关于使用StringBuilder, StringWriter, HtmlTextWriter, RenderControl等，但仍然不明白如何使其工作。

下面是我的代码:

        public void Email()
    {            
        string conn = "Data Source=pc-..";
        System.Data.SqlClient.SqlConnection sqlConn = new System.Data.SqlClient.SqlConnection(conn);
        sqlConn.Open();
        SqlCommand sendGrid = new SqlCommand("SELECT * FROM tblSomething", sqlConn);
        GridView grd = new GridView();
        if (sendGrid != null)
        {
            grd.DataSource = sendGrid.ExecuteReader();
            grd.DataBind();
        }
        StringBuilder sb = new StringBuilder();
        StringWriter sw = new StringWriter(sb);
        HtmlTextWriter htw = new HtmlTextWriter(sw);
        grd.RenderControl(htw);
        MailMessage mail = new MailMessage();
        mail.To.Add("ToWhoEmail");
        mail.From = new MailAddress("FromWho");
        mail.Subject = "SubjectSomething";
        mail.IsBodyHtml = true;
        mail.BodyFormat = System.Net.Mail.MailMessage.IsBodyHtml.Html;
        // At this line above i get an error. He doesn't recognize BodyFormat = ...;
        // System.Web.Mail.MailFormat is obsolete.
        // The recommended alternative is: System.Net.Mail.MailMessage.IsBodyHtml
        mail.Body = sb.ToString();
        SmtpClient smtp = new SmtpClient("...");
        smtp.Send(mail);}

我也试过在不同的cs文件中制作gridview，并使用:SendGrid.MakeGrid()中的邮件。Body = "…";但所有我得到的是:System.Web.UI.WebControls.GridView在我的电子邮件。感谢所有的帮助，提前谢谢你。

问候,马蒂斯著名

grd.DataSource = sendGrid;

grd.DataSource = sendGrid.ExecuteReader();