How to: Create reminders that should trigger an event to be handled in a Windows application?

Question

Hello all.

I need to develop a windows application with .NET 3.5 that needs to have a calendar and user can schedule appointments.

I want (not with a windows-service) that while the application is on, all the reminders that are set up for this user + reminders that admins set them up, should trigger an event in the application so I can handle it (showing the user a message, notify icon or whatever), once its datetime becomes now. The data is saved in SQL Server and accessible from many computers, the admin should be able to externally create reminders for users.

Any approaches?

Answer 1

You should really avoid popups. Popups are generally considered not user friendly. They interrupt the user's work flow. Even worse, they steal the keyboard input. What if the users was typing an important email right now?

Instead you might provide a nice, pleasant sound and a task bar bubble or similar.

Answer 2

Locally, you could trigger the events using a timer that check the current time e.g. every 10 seconds or more often. The clients should regularily synchronize with the database server, querying all data for the current day or (on user demand) later events. This allows the clients to run and to remind the user even when the network fails for some time.

Another very interesting option is a server side reminder tool next to the database. It generates reminders and sends them via XMPP to the clients. The client machines don't need a special software anymore - any Jabber client would be sufficient, although a special software acting as an XMPP client would be possible, too.