Introduction
One of the coolest features in the new Mango (7.1) update is the ability of
applications to do background tasks (finally!). Two of the new features brought
about by this are the Alarm and Reminder classes. They essentially give you, the
developer, access to use OS level alarms, and calendar-like reminders. All of
this lives under the Microsoft.Phone.Scheduler namespace, which I suggest you
check out if you haven't already. Anyways, on with some demos!
Alarm
![AlarmWP7]()
As you can see, this alarm looks exactly like the system one. I've annotated the
above picture to show what you can and cannot change in the dialog. Now let's
look at the code for creating this.
public
void
setAlarm()
{
if
(ScheduledActionService.Find("My
Alarm")
!=
null)
ScheduledActionService.Remove("My
Alarm");
Alarm a =
new
Alarm("My
Alarm")
{
Content =
"Alarm",
BeginTime = DateTime.Now.AddMinutes(1)
};
ScheduledActionService.Add(a);
}
This function is very simple and just shows the lifecycle of using an alarm
repeatedly in your application. When creating an Alarm (or Reminder) you give it
a name. This is so you can identify what has or has not triggered or whatever
other logic you want to perform. These names are also unique, so you can't add
two alarms with the same name. The first section of code makes sure that our
alarm isn't still in the Scheduler, but if it is, removes it. We then make out
alarm, give it some info; Content, as shown in the picture, and BeginTime, which
is when your alarm should go off, represented as a DateTime object. The last
step is to add the alarm to the Scheduler queue.
One thing to note is that while you can see the Title property of the Alarm
object, setting it will result in an error. If you want to change the Title,
keep reading to look at Reminders.
Reminder
![ReminWP7]()
The Reminder is a little more customizable than
the Alarm, as you can change the title. Also, if a user taps a Reminder, it will
take them to your application; the Alarm does not do that. Creating one is very
similar, as shown below.
public void setReminder()
{
if (ScheduledActionService.Find("My Reminder") != null)
ScheduledActionService.Remove("My Reminder");
Reminder r = new Reminder("My Reminder")
{
Content = "Remind Me",
BeginTime = DateTime.Now.AddMinutes(1),
Title = "My Title"
};
ScheduledActionService.Add(r);
}
This code is pretty much identical to our Alarm, except that now we can set the Title. There is an unused property here, NavigationUri, which allows you to customize the information
passed to your application when the user taps the Reminder, which is beyond the scope of this simple introduction.
Conclusion I hope this brief introduction has helped you understand these two new features and if it brought up any questions, feel free to ask in the comments.