Today I was up bright and early to fly out to the Netherlands for TechDays 2013. I’m doing some sessions on Windows Phone and Gadgeteer. I’ve been doing sessions in TechDays for quite a while, they have a great atmosphere at the conference and the audiences are always great.

Today was no exception. You can tell the quality of the audience by the questions that you get at the end, and in this session I got some really good ones. One of which I couldn’t answer at the time. The question concerned the behaviour of application created alerts. A Windows Phone program can create alerts which will appear at some point in the future. These are useful because you get them whether the application is running or not. When the alert fires the user can drop back to the application and do something. I made a program for timing eggs which causes an alert when the egg is ready. What the delegate wanted to know was what happened to the alert if the phone is displaying the lock screen, or powered off.

I’ve done some experiments , and now I think I know the answer. If the phone is locked the alert will appear on top of the lock screen, just like any other appointment would. If the phone is turned off, you don’t seem to get the alert displayed when it is powered back on though. Hope this helps.

You can find the slides and the sample code (including the egg timer) here.