谢谢！
private void btSend_Click(object sender, System.EventArgs e)
{
string zhusong = this.tbZs.Text.Trim();//文件的主送人
string baosong = this.tbBs.Text.Trim();//文件的报送人
string Subject = this.tbSubject.Text.Trim();//文件的主题
string Body = this.tbBody.Text;//文件的内容
string Priority = this.ddlPriority.SelectedValue;//文件的优先级
//文件的上传
string[] Attachments = new string[this.ddlUpFile.Items.Count];
for (int i=0;i<this.ddlUpFile.Items.Count;i++)
{
Attachments[i] = this.ddlUpFile.Items[i].Value;
}

if (myemail.SendEmail(zhusong,bongsong,Subject,Body,Priority, Attachments))
{
Page.RegisterClientScriptBlock("ok","<script language=c#>alert('发送成功')</script>");
}
else
{
Page.RegisterClientScriptBlock("ok","<script language=c#>alert('发送失败')</script>");
}
}