Exit an app

[Gerhard Kreuzer]

Hi,

 

I have nearly done my 'Proof of Concept' app, as far as nRoute is involved, but there is still a point open.

 

How can I stop the app?

 

I take a look at the FuturDesktop app and as far as I found out, there is a button and within it's event handler in the code behind file (==UI layer) a the Close-method of the main window is called.

 

First of all, there will be some code necessary to safely close down an app, so this button should call a method of the associated VM first.

Second, I want to close down my app safely, after some time of hanging around without usage. Its also a security option we have to take. So I need a way to close down programatically.

Third, the concept, that views depending on VM's but NOT other way round is the big advantage of MVVM over other patterns, so I would not break this by adding some hack which allows me to call the Close method of my main window from some VM.

 

Any idea around?

 

Thanks

 

Gerhard

[Rishi Oberoi]

If you need a programmatic way to know when an application is exiting, consider subscribing to the ApplicationStateInfo channel. 

Below is an example from the Square-Away game (see http://www.orktane.com/Blog/post/2010/07/19/Square-Away-A-Windows-Phone-7-Game-using-nRoute.aspx) where I use the knowledge of when the application is closing to only save the highest score just once in the application's lifetime:

    [MapService(typeof(IHighScoreService), Lifetime=InstanceLifetime.Singleton)]
    public class HighScoreService 
        : IHighScoreService
    {
        private const string HIGH_SCORE_KEY = "SQUAREAWAY_HIGH_SCORE_KEY";
 
        private int? _highestRecordedScore;
        private IDisposable _subscriptionToken;
 
        [ResolveConstructor]
        public HighScoreService(IChannel<ApplicationStateInfo> stateInfoChannel)
        {
            if (stateInfoChannel == null) throw new ArgumentNullException("stateInfoChannel");
            _subscriptionToken = stateInfoChannel.Subscribe(OnApplicationStateChanged, null, ThreadOption.UIThread, false);
 
            if (IsolatedStorageSettings.ApplicationSettings.Contains(HIGH_SCORE_KEY))
            {
                _highestRecordedScore = Convert.ToInt32(IsolatedStorageSettings.ApplicationSettings[HIGH_SCORE_KEY]);
            }            
        }
 
#region Channel Handler
 
        private void OnApplicationStateChanged(ApplicationStateInfo stateInfo)
        {
            if (stateInfo.CurrentState == ApplicationState.Exiting)
            {
                IsolatedStorageSettings.ApplicationSettings.Save();
                _subscriptionToken.Dispose();
            }
        }
 
#endregion
 
#region IHighScoreService Implementation
 
        public void RegisterLastScore(int score)
        {
            if (score > _highestRecordedScore.GetValueOrDefault(-1))
            {
                IsolatedStorageSettings.ApplicationSettings[HIGH_SCORE_KEY] = score;                
                _highestRecordedScore = score;
            }
        }
 
        public int? GetHighestScore()
        {
            return _highestRecordedScore;
        }
 
#endregion
 
    }

Note how we check the current state of the application using "stateInfo.CurrentState" property - that means you can use this channel with the application's other lifetime events like starting, started etc.

Cheers,

Rishi

[Gerhard Kreuzer]

Hi Rishi,

 

thanks, will go into it, but I want to stop the app programmatically. I want not to know, when somebody press some exit button, I want 'press' this button programmatic, because some user forgot to log out and this is a security issue.

 

With best regards

 

Gerhard

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Von: nro...@googlegroups.com [mailto:nro...@googlegroups.com] Im Auftrag von Rishi Oberoi
Gesendet: Mittwoch, 23. Februar 2011 11:15
An: nro...@googlegroups.com
Betreff: [nRoute] Re: Exit an app

[Rishi Oberoi]

Google is your friend:

http://stackoverflow.com/questions/2820357/how-to-exit-a-wpf-app-programmatically

http://social.msdn.microsoft.com/Forums/en/wpf/thread/68bea444-1fa7-4948-8b8c-bf61fbc6dc2b

Rishi

[Gerhard Kreuzer]

Thanks, I search in help amd msdn .....

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Von: nro...@googlegroups.com [mailto:nro...@googlegroups.com] Im Auftrag von Rishi Oberoi

Gesendet: Mittwoch, 23. Februar 2011 11:26
An: nro...@googlegroups.com
Betreff: Re: AW: [nRoute] Re: Exit an app