How to open a new window using MVVM Light Toolkit

Question

I am using MVVM Light toolkit in my WPF application. I would like to know what is the best approach for opening a new window from an existing window. I have got this M

Answer 1

I find the best way to approach this, is opening and closing the window from the ViewModel. As this link suggests,

1. Create a DialogCloser class

    public static class DialogCloser
    {
        public static readonly DependencyProperty DialogResultProperty = DependencyProperty.RegisterAttached("DialogResult", typeof(bool?), typeof(DialogCloser), new PropertyMetadata(DialogResultChanged));

        private static void DialogResultChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var window = d as Window;
            if (window != null) window.Close();
        }

        public static void SetDialogResult(Window target, bool? value)
        {
            target.SetValue(DialogResultProperty, value);
        }
    }

2. Create a Base ViewModel inheriting from GalaSoft.MvvmLight.ViewModelBase with there additional members. Once done, use this viewmodel as base for other viewmodels.

    bool? _closeWindowFlag;
    public bool? CloseWindowFlag
    {
        get { return _closeWindowFlag; }
        set
        {
            _closeWindowFlag = value;
            RaisePropertyChanged("CloseWindowFlag");
        }
    }

    public virtual void CloseWindow(bool? result = true)
    {
        Application.Current.Dispatcher.BeginInvoke(DispatcherPriority.Background, 
        new Action(() =>
        {
            CloseWindowFlag = CloseWindowFlag == null ? true : !CloseWindowFlag;
        }));
    }

3. In the view, Bind the DialogCloser.DialogResult dependency property with the CloseWindowFlag property in the base viewmodel.

Then you can open/close/hide the window from the viewmodel.