CODEWITHSUNDEEP
c#wpfmvvm
RockGuitarist1
RockGuitarist1

Reputation: 115

Manually Running Specific Method Within Viewmodel

I looked around a bit on how to manually trigger a Viewmodel to run again, but wasn't sure they were directed towards what I actually want.

What I want to do is be able to run a specific Method that is inside of my Viewmodel whenever a specific Window is closed, without running all of them. Is there a way that I could bind this Method to the Closed Event of the second Window? Thanks.

Upvotes: 0

Views: 49

Answers (2)

dman
dman

Reputation: 145

are you using MVVM Light or any other MVVM framework ?

if so: you have multiple options depending on your design you might want to choose

  1. EventToCommand
  2. Messenger(If i go this route create a Behavior and keep logic there , so its clean)

Upvotes: 0

FCin
FCin

Reputation: 3925

If you want to stick to MVVM and do it properly, in a easy to extend and maintain way you can do this like this:

public class FirstViewModel : IWindowCloseNotifier {

   public SecondViewModel SecondVm { get; set; }

    public FirstViewModel() 
    {
      SecondVm = new SecondViewModel(this);  
    }

    public void Close(IWindowCloseNotifierArgs args)
    {
       // Window is now closed!
    }
}

Interface ensures that SecondViewModel can use only Close method.

 public interface IWindowCloseNotifier {
        void Close(IWindowClosedArgs args);
    }

    public class SecondViewModel {

        private readonly IWindowCloseNotifier _windowCloseNotifier;

        public SecondViewModel(IWindowCloseNotifier windowCloseNotifier) {
          _windowCloseNotifier = windowCloseNotifier;
        }

        public void OnClose()
        {
           _windowCloser.Close(your args);
        }
    }

If your SecondViewModel is not a child of FirstViewModel then use Publish Subscribe Pattern to communicate between viewmodels.

My naming is not great, but I don't have any other ideas.

Upvotes: 1

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