Asp.net mvc MailDefinition/MailMessage和basepath不能为空

我正在用下面的代码创建一个

MailMessage

，调用

mail.CreateMailMessage

时收到此错误

// Create a dummy page and use it to load a dummy control so that CreateMailMessage() will not complain
Page page = new Page();
DummyControl control = (DummyControl)page.LoadControl("~/DummyControl.ascx");           
MailMessage message = mail.CreateMailMessage(reciever, RecieptReplacements, dummycontrol);

值不能为null。参数名称：basepath

有人知道会出什么问题吗

public void SendReciept(string reciever)
    {
        MailDefinition mail = new MailDefinition();
        mail.IsBodyHtml = true;

        mail.BodyFileName = "~/file.txt";
        mail.Subject = "Subject";
        mail.From = "noreply@xxx.com";
        mail.Priority = System.Net.Mail.MailPriority.Normal;

        MailMessage message = mail.CreateMailMessage(reciever, RecieptReplacements, new System.Web.UI.Control());

        ...
    }

    ListDictionary RecieptReplacements
    {
        get
        {
            ListDictionary replacements = new ListDictionary();

            replacements.Add("<%Name%>", "Name");

            return replacements;
        }
    }

public void sendReceipt（字符串接收器）
{
MailDefinition mail=新邮件定义（）；
mail.IsBodyHtml=true；
mail.BodyFileName=“~/file.txt”；
mail.Subject=“Subject”；
mail.From=”noreply@xxx.com";
mail.Priority=System.Net.mail.MailPriority.Normal；
MailMessage=mail.CreateMailMessage（receiver，receiptreplacements，new System.Web.UI.Control（））；
...
}
ListDictionary接收替换
{
得到
{
ListDictionary replacements=新建ListDictionary（）；
替换。添加（“，”名称“）；
归还替代品；
}
}

您需要创建一个Web用户控件（.ascx文件），然后加载该控件并将其传递给

CreateMailMessage

// Create a dummy page and use it to load a dummy control so that CreateMailMessage() will not complain
Page page = new Page();
DummyControl control = (DummyControl)page.LoadControl("~/DummyControl.ascx");           
MailMessage message = mail.CreateMailMessage(reciever, RecieptReplacements, dummycontrol);

看看这个，它解释了为什么，并提供了上述解决方案