I've got plans for an application in which I need to know with certainty the current time. So I don't want to trust the time as reported by the user's device. Instead, I need to retrieve the time from a server. I made a NTP (Network Time Protocol) client for retrieving this information. This is something that couldn't be done on Windows Phone 7 prior to Mango. But with the fall update (Mango), access to sockets is granted.
The use of the client is pretty simple. At a minimum, one can create the client with the default constructor, subscribe to the ReceivedTime event, and call the RequestTime method to initiate a request. The ReceivedTime event may be called on a thread other than the UI thread so remember to use a dispatcher when making UI updates.
This is an example of a client using the code to display both the system time and the network time.
public partial class MainPage : PhoneApplicationPage
{
private NtpClient _ntpClient;
public MainPage()
{
InitializeComponent();
_ntpClient = new NtpClient();
_ntpClient.TimeReceived += new EventHandler<NtpClient.TimeReceivedEventArgs>
(_ntpClient_TimeReceived);
}
void _ntpClient_TimeReceived(object sender, NtpClient.TimeReceivedEventArgs e)
{
this.Dispatcher.BeginInvoke(() =>
{
txtCurrentTime.Text =
e.CurrentTime.ToLongTimeString();
txtSystemTime.Text =
DateTime.Now.ToUniversalTime().
ToLongTimeString();
});
}
private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
{
}
private void UpdateTimeButton_Click(object sender, RoutedEventArgs e)
{
_ntpClient.RequestTime();
}
}
CodeProject
