async void HardwareButtons_BackPressed(object sender, Windows.Phone.UI.Input.BackPressedEventArgs e)
{
e.Handled = true; // We've handled this button press
if (!IsExit)
{
//ExitSB.Begin();
IsExit = true;
if(dt == null)
{
dt = new DispatcherTimer();
}
dt.Interval = TimeSpan.FromSeconds(2);
dt.Tick += timer_Tick;
dt.Start();
}
else
{
App.Current.Exit();
}
}
void timer_Tick(object sender, object e)