在asp.net中自动发送发票电子邮件

Question

Right now our asp.net website is sending invoice manually, Is it possible send email to customers automatically every 5 minutes? All invoices is using software to put in SQL Server Database, after put in database, they need to send to different customer email address with attached PDF file. That means the code needs collect new invoices information from database every 5 minutes and send it. Then create a log file include the successful and unsuccessful invoice sent to accounting.

Can I use task scheduler or windows services?

Answer 1

Create a page called CronMail.aspx and send the emails in the load event (I explain the idea using some pseudocode):

void Page_Load(object source, EventArgs e)
{
     //1. Check that more than 5 minutes happened before last sent
     DateTime lastSent = ...;
     if (DateTime.Now().Substract(lastSent).Minutes < 5)
          return;

     //2. Get your invoices and PDF files
     var dataToSent = ...;

     //3. Send your invoices
     foreach(var item in dataToSent) 
     {
          //4. Save sent date every time to avoid resending in case the whole operation takes more than 5 minutes 
          saveSentTime();

         //5. Finally send your data
     }
}

Then you can use the Windows tasks scheduler to call your URL every 5 minutes: http://your_website/CronMail.aspx

Here is an example: https://superuser.com/questions/447368/set-windows-scheduler-to-schedule-open-a-website-webpage-or-the-bookmark (use chrome instead of iexplorer)

Answer 2

The Hangfire library is a complete back-end job scheduler and background processor that runs on top of more recent versions of ASP.NET. It runs on its own (there's a special IIS app pool configuration required - "AlwaysRunning") without the need for an external web-page ping, or task scheduler. You can schedule lots of jobs to run as often as once per minute.

I've had lots of success with it.