ASP.NET:发送带有附件的电子邮件

我想建立一个联系我们页面，使用户能够发送带有附件的邮件。我写了下面的代码，但我不知道它为什么不和我一起工作。这是工作的FileUpload前加入，但后加入的形式，它不工作。

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Net.Mail;

using System.Net;

using System.Text;

 



public partial class Contact : System.Web.UI.Page

{

    protected void Page_Load(object sender, EventArgs e)

    {

        if (!IsPostBack)

        {

            MultiView1.SetActiveView(ViewForm);

        }

 

    }

 



 

    protected void btnSend_Click(object sender, ImageClickEventArgs e)

    {

        SmtpClient sc = new SmtpClient("Mail Server");

        StringBuilder sb = new StringBuilder();

        MailMessage msg = null;

 

        sb.Append("Message from: " + txtName.Text + "\n");

        sb.Append("Email: " + txtEmail.Text + "\n");

        sb.Append("Message   : " + txtMessage.Text + "\n");

        

        //Attach file using FileUpload Control and put the file in memory stream

        if (FileUpload1.HasFile)

        {

            msg.Attachments.Add(new Attachment(FileUpload1.PostedFile.InputStream, FileUpload1.FileName));

        }

 

        try

        {

            msg = new MailMessage(txtEmail.Text,

                "Receiver Email", "Email Title",

                sb.ToString());

 

            sc.Send(msg);

            MultiView1.SetActiveView(ViewConfirm);

        }

        catch (Exception ex)

        {

            throw ex;

            // something bad happened

            //Response.Write("Something bad happened!");



        }

        finally

        { 

 

            if (msg != null)

            {

                msg.Dispose();

            }

 

        }

    }

 

}