// This method saves the application state before entering background state. It fires the event OnBackgroundEntering to collect
// state data from the current subscriber and saves it to the local storage.
public async Task SaveStateAsync()
{
var suspensionState = new SuspensionState()
{
SuspensionDate = DateTime.Now
};
var target = OnBackgroundEntering?.Target.GetType();
var onBackgroundEnteringArgs = new OnBackgroundEnteringEventArgs(suspensionState, target);
OnBackgroundEntering?.Invoke(this, onBackgroundEnteringArgs);
await ApplicationData.Current.LocalFolder.SaveAsync(StateFilename, onBackgroundEnteringArgs);
}
public OnBackgroundEnteringEventArgs(SuspensionState suspensionState, Type target)
{
SuspensionState = suspensionState;
Target = target;
}