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It’s also very important to remember that network status might have changed while the app was
suspended. Apps that watch the networkstatuschanged event should also refresh their
connectivity-related state within their resuming handler.
As a final note, check out the Troubleshooting and debugging network connections topic in the
documentation, which has a little more guidance on responding to network changes as well as network
errors.
Cost Awareness
If you ever crossed between 3G roaming territories with a smartphone that’s set to automatically
download email, you probably learned the hard way to disable syncing in such circumstances. I once
drove from Washington State into Canada without realizing that I would suddenly be paying
$15/megabyte for the privilege of downloading large email attachments. Of course, since I’m a
law-abiding citizen I did not look at my phone while driving (wink-wink!) to notice the roaming
network. Well, a few weeks later I knew what “bill shock” was all about!
The point here is that if users conclude that your app is responsible for similar behavior, regardless of
whether it’s actually true, the kinds of rating and reviews you’ll receive in the Windows Store won’t be
good! It’s vital, then, to pay attention to changes in the cost of the connection profiles you’re using,
typically the Internet profile. Always check these details on startup, within your networkstatuschanged
event handler, and within your resuming handler.
You—and all of your customers, I might add—can track your app’s network usage in the App History
tab of Task Manager, as shown below. Make sure you’ve expanded the view by tapping More Details on
the bottom left if you don’t see this view. You can see that it shows Network and Metered Network
usage along with the traffic due to tile updates:
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