如何将捕获到的ASP.NET MVC3异常记录到文件？

Question

I am trying to fix a script on a remote server that is supposed to be sending e-mails with SmtpClient(). Unfortunately, it fails, and there's a generic catch-all exception that outputs an error message to the view and then just carries merrily on it's way.

What I instead want to do, because I can't really remotely debug it (and I don't seem to be able to produce the issue locally), is have the exception that is thrown logged to a file for me to download via FTP (I know, shared hosts) and peruse in order to figure out what's going on.

Here is the code:

try
{
    var client = new SmtpClient();

    var emailRecipients = new List<string> { "test@example.co.uk" };

    var message = new MailMessage(Sender, emailRecipients.First());

    Person recipient = null;
    if (cbr.RecipientId.HasValue)
    {
        recipient = (from p in Entities.People where p.Id == cbr.RecipientId.Value select p).FirstOrDefault();
    }

    message.Subject = "Callback Request from " + cbr.Name;
    message.Body = DateTime.Now.ToShortDateString() + " " + DateTime.Now.ToShortTimeString() + "\r\n\r\n" + "A callback request by \"" + cbr.Name + "\" has been made from the Foreman Laws website";

    if (!string.IsNullOrWhiteSpace(cbr.SourceURL))
    {
        message.Body += ", from the following URL: " + cbr.SourceURL + "\r\n\r\n";
    }
    else
    {
        message.Body += ".\r\n\r\n";
    }

    if (cbr.DepartmentId.HasValue)
    {
        var department = (from d in Entities.CustomRouteItems where d.Id == cbr.DepartmentId.Value select d).FirstOrDefault() as CustomPage;
        if (department != null)
        {
            message.Body += "Request for someone in " + department.Name + " to call back.\r\n";
            String email;
            if (DepartmentEmails.TryGetValue(department.Name, out email))
            {
                message.CC.Add(email);
            }
        }
        else
        {
            message.Body += "Request for anyone to call back (no department selected).\r\n";
        }
    }
    else if (recipient != null)
    {
        message.Body += "Request for " + recipient.Name + " to call back.\r\n";
        if (!string.IsNullOrWhiteSpace(recipient.Email))
        {
            message.CC.Add(recipient.Email);
        }
    } 
    else
    {
        message.Body += "Request for anyone to call back (no department selected).\r\n";
    }

    if (recipient != null)
    {
        message.Body += "The request was made from " + recipient.Name + "'s profile page on the site.\r\n\r\n";
    }

    message.Body += cbr.Name + "'s phone number is: " + cbr.TelephoneNumber + "\r\n";
    if (!string.IsNullOrWhiteSpace(cbr.Email))
    {
        message.Body += cbr.Name + "'s email address is " + cbr.Email + "\r\n";
    }

    message.Body += "\r\n";

    if (!string.IsNullOrWhiteSpace(cbr.SpecificTime))
    {
        message.Body += "The following time was specified for the callback: " + cbr.SpecificTime + "\r\n\r\n";
    }

    client.Send(message);

    cbr.Sent = true;
}
catch (Exception e)
{
    ModelState.AddModelError("Sent", "Sorry, your request could not be sent at this time, please try again later.");
}

Answer 1

Download Log4net and add reference to your project.

Configure a rolling file appender .

Now use this code in your project where you want to log the error.

---

using log4net;
Class YourClassName
{
    static readonly ILog _log = LogManager.GetLogger(typeof(YourClassName));
    public void DoWork()
    {
        try
        {
             //Your code goes here [written in your question]
        }
        catch(Exception e)
        {
            _log.Fatal(e);
        }
    }
}