Close a view from a viewmodel in MVVM

Question

I have seen many examples over the net but I am not able to figure out what i am doing wrong here. I need to close a view from a view model. Below is the code i have tried:

ViewModel:

public class ViewModel
{
    public event EventHandler RequestClose;
    public ViewModel()
    {

    }
}

//Calling the event from view model to close the view from a method in View Model This event is called on a button click

private void Download()
{
//Download Logic
if(RequestClose != null)
                RequestClose(this,EventArgs.Empty);
 }

View:

ViewModel vm = new ViewModel();
vm.RequestClose += delegate(object sender, EventArgs args) {this.Close();}
this.DataContext = vm;

http://ericlippert.com/2014/03/05/how-to-debug-small-programs/ — Samuel, Jun 12 '14 at 06:08

score 1 · Accepted Answer · answered Jun 12 '14 at 06:20

1

You fire the RequestClose event in the ViewModel constructor which is too early to be catched by the event registration.

answered Jun 12 '14 at 06:20

shahar eldad

861
1
12
31

I am calling RequestClose later from a method in ViewModel, not in the constructor. – user2480288 Jun 12 '14 at 06:39
My bad.. I moved the RequestClose event from the constructor. It works now. – user2480288 Jun 12 '14 at 19:04

score 0 · Answer 2 · edited May 23 '17 at 12:13

0

The best MVVM solution is to use an attached behavior, as outlined in the top rated answer to this question How should the ViewModel close the form?

edited May 23 '17 at 12:13

Community

1
1

answered Jun 12 '14 at 14:17

Peregrine

4,287
3
17
34

score -1 · Answer 3 · answered Jun 12 '14 at 08:09

I faced a similar problem earlier, and did the following: In the viewmodel, create a command that you can bind to (I personally use MvvmLight and its RelayCommand)

public class ViewModel
{
   public RelayCommand<object> CloseWindowCommand {get; private set;}

   public ViewModel()
   {
      CloseWindowCommand = new RelayCommand<object>(CloseTheWindow);
   }

   private void CloseWindow(object obj)
   {
      var window = obj as Window;
      if(window != null) 
         window.Close();
   }
}

In my view, I have button that triggers this command, e.g.

Button Content="Close" Command="{Binding CloseWindowCommand}" CommandParameter="{Binding ElementName=NameOvViewModel}"

I realize now, that this may require the use of MvvmLight, but I hope it offers some guidance on a possible solution to your question.

-1 Handling `Window`s in the view model breaks the whole MVVM pattern. — Sheridan, Jun 12 '14 at 16:12

Close a view from a viewmodel in MVVM

3 Answers3