使用ICommand添加到ObservableCollection

Question

我通过ICommand向ObservableCollection添加项目时遇到问题。 第二个窗口用于编辑此ObservableCollection。 当我添加新项目时，第二个窗口中的ListView显示新项目，但第一个窗口不显示。 如何从我的命令中添加我的Obseravle Collection？

这是我的ObservableCollection：

 public  class ProductExtrasObservableCollection : ObservableCollection<ProductViewModel>
{
    public AddToExtrasObservableCollectionCommand AddToExtrasObservableCollectionCommand { get; set; }
    public DeleteExtrasProductCommand DeleteExtrasProductCommand { get; set; }


    public ProductExtrasObservableCollection() : base()
    {
        AddToExtrasObservableCollectionCommand = new AddToExtrasObservableCollectionCommand(this);
        DeleteExtrasProductCommand = new DeleteExtrasProductCommand(this);

        Add(new ProductViewModel(new Product { Name = "Sugar", Price = 0.05, IsDrink = false }) { IsChecked = false } );
        Add(new ProductViewModel(new Product { Name = "Milk", Price = 0.2, IsDrink = false }) { IsChecked = false });
        Add(new ProductViewModel(new Product { Name = "Cream", Price = 0.1, IsDrink = false }) { IsChecked = false });
        Add(new ProductViewModel(new Product { Name = "Canela", Price = 0.15, IsDrink = false }) { IsChecked = false });
    }
}

}

这是我的班级命令：

 public  class AddToExtrasObservableCollectionCommand : ICommand
{
    ProductExtrasObservableCollection Collection { get; set; }

    public AddToExtrasObservableCollectionCommand(ProductExtrasObservableCollection Coll)
    {
        this.Collection = Coll;
    }

    public event EventHandler CanExecuteChanged;

    public bool CanExecute(object parameter)
    {
        return true;
    }

    public void Execute(object parameter)
    {
       Collection.Add(new ProductViewModel(parameter as Product));
    }

}

这是按钮的XAML：

<Button  
        Content="Add to Extras"
        HorizontalAlignment="Left"
        Margin="458,184,0,0"
        VerticalAlignment="Top"
        Width="88" 
        Height="60" 
        Command="{Binding AddToExtrasObservableCollectionCommand, Source={StaticResource ExtrasData}}" 
        CommandParameter="{Binding NewProduct, Source={StaticResource ViewModel}}" />