如何在Task.Run中调用异步方法

我需要以异步方式发送邮件。我已经想出了使用剃刀生成器从剃刀视图生成Html模板。现在我需要使用SmtpClient。SendMailAsync将html作为邮件发送。但是我发现Razor生成器需要相当长的时间，我不想在我的send mail方法中包含模板生成部分，因为send mail方法不应该关心获取Html模板。

我有样例代码:

public static void SendEmailAsync<TModel>(TModel model, string templatePath, string subj, string toEmail, string cc = null, string bcc = null)
    {
        string templateFilePath = HostingEnvironment.MapPath(templatePath);
        // Generate the email body from the template file.
        // 'templateFilePath' should contain the absolute path of your template file.
        if (templateFilePath != null)
        {
            Task.Run(() =>
            {
                var emailHtmlBody = Engine.Razor.RunCompile(File.ReadAllText(templateFilePath),
                templateFilePath, model.GetType(), model);
                SendEmailAsync(subj, emailHtmlBody, toEmail, cc, bcc);
            });
        }
        else
        {
            throw new System.Exception("Could not find mail template.");
        }
    }

和SendMailAsync的签名是:

static async Task SendEmailAsync(string subj, string message, string toEmail, string cc = null, string bcc = null)
    {
        //Reading sender Email credential from web.config file  
        string fromEmail = ConfigurationManager.AppSettings["FromEmail"].ToString();
        string fromName = ConfigurationManager.AppSettings["FromName"].ToString();
        //creating the object of MailMessage  
        MailMessage mailMessage = new MailMessage();
        mailMessage.From = new MailAddress(fromEmail, fromName); //From Email Id  
        mailMessage.Subject = subj; //Subject of Email  
        mailMessage.Body = message; //body or message of Email  
        mailMessage.IsBodyHtml = true;
        string[] toMuliId = toEmail.Split(',');
        foreach (string toEMailId in toMuliId)
        {
            mailMessage.To.Add(new MailAddress(toEMailId)); //adding multiple TO Email Id  
        }

        if (cc != null)
        {
            string[] ccId = cc.Split(',');
            foreach (string ccEmail in ccId)
            {
                mailMessage.CC.Add(new MailAddress(ccEmail)); //Adding Multiple CC email Id  
            }
        }
        if (bcc != null)
        {
            string[] bccid = bcc.Split(',');
            foreach (string bccEmailId in bccid)
            {
                mailMessage.Bcc.Add(new MailAddress(bccEmailId)); //Adding Multiple BCC email Id  
            }
        }
        SmtpClient smtp = new SmtpClient
        {
            EnableSsl = true,
            Credentials = new NetworkCredential("", "")
        };
        //network and security related credentials  
        await smtp.SendMailAsync(mailMessage); //sending Email  
    }

没有抛出异常，但我得到错误:

系统。InvalidOperationException:此时不能启动异步操作。异步操作只能在异步处理程序或模块中启动，或者在Page生命周期中的某些事件期间启动。如果在执行页面时发生此异常，请确保页面标记为<%@ Page Async="true" %>。此异常还可能表明试图调用"async void"方法，这在ASP中通常不支持。. NET请求处理。相反，异步方法应该返回一个Task，调用者应该等待它。

await Task.Run(async () =>
{
    await DoAsyncMethodAsync();
});

Engine.Razor.RunCompile

Engine.Razor.Run