Prism2 / MVVM Close View from ViewModel

Question

How to close a view from its ViewModel?

I have a WPF window that has defined several regions and is used as a wrapper to host the views for my application. I would like the View to be able to remove itself from the region or close it from the tabbed container. How can I execute this behavior from ViewModel.

Answer 1

It really depends on your application architecture, but here is how I do it with Prism.

First, I want to say that this is normal if your VM refers to the view so long as it is not a specific implementation of the View, that is, links through the interface.

View ViewModel, , , StockTraderRI. , IView IViewModel. IViewModel "" IView.

( , , ... . StockTraderRI), , .

:

myRegion.Remove(myIViewModel.View);

, , , "". IEventAggregator, . , .

Answer 2

ViewModel ( ) View, . Event ViewModel, , .

, , ( ).

Answer 3

How my input module looks like this:

    public class LoginModule : IModule
{
    private readonly IUnityContainer container;

    public LoginModule(IUnityContainer container)
    {
        this.container = container;
    }

    #region IModule Members

    public void Initialize()
    {
        this.container.RegisterType<ILoginController, LoginController>(new ContainerControlledLifetimeManager());
        this.container.RegisterType<ILoginView, LoginView>();
        this.container.RegisterType<ILoginViewModel, LoginViewModel>();

        ILoginController controller = this.container.Resolve<ILoginController>();
        controller.Run();
    }

    #endregion
}

This is the controller:

    public class LoginController : ILoginController
{
    private readonly IRegionManager regionManager;
    private readonly ILoginViewModel model;

    public LoginController(IRegionManager regionManager, ILoginViewModel model)
    {
        this.regionManager = regionManager;
        this.model = model;
        model.RequestClose += new EventHandler(model_RequestClose);
    }

    void model_RequestClose(object sender, EventArgs e)
    {
        regionManager.Regions["LoginRegion"].Remove(model.View);
    }

    #region ILoginController Members

    public void Run()
    {
        // Register views here
        regionManager.Regions["LoginRegion"].Add(model.view);
    }

    #endregion
}

And this is my ViewModel:

    public class LoginViewModel : ViewModelBase, ILoginViewModel
{
    IEventAggregator _eventAggregator;
    RelayCommand _loginCommand;
    private readonly UserProfileRepository _userProfileRepository;
    public event EventHandler RequestClose;

    public ICommand LoginCommand
    {
        get
        {
            if (_loginCommand == null)
            {
                _loginCommand = new RelayCommand(
                    param => this.Login(),
                    param => this.IsValid());
            }
            return _loginCommand;
        }
    }

    public LoginViewModel(IEventAggregator eventAggregator, UserProfileRepository userProfileRepository, ILoginView view)
    {
        this._eventAggregator = eventAggregator;
        this._userProfileRepository = userProfileRepository;
        this.View = view;
    }

    #region ILoginViewModel Members

    public ILoginView View { get; private set; }

    #endregion
}