how to update gridview after collection has been set
===

I am trying to binding GridView to a collection, and I want to update GridView after the collection has been set.

The reason I don't use ObservableCollection is that it will block UI if collection is large(more than 1000 items, and I want to show all items after all items has been added).
In metro style app, there is no BindingList class for C# use, so do I need to implement my own collection class? I tried to implement a class inherited IList and INotifyPropertyChanged but it's not work because PropertyChanged = null

I did something like this:

    class MyBindingList<T> : IList<T>, INotifyPropertyChanged
    {
        public virtual event PropertyChangedEventHandler PropertyChanged;
        public void RaiseChanged()
        {
            this.PropertyChanged(this, new PropertyChangedEventArgs("here"));
        }
    }
    MyBindingList<Item> list = new MyBindingList<Item>();
    ItemsGridView.ItemsSource = list;

can someone give me suggestion? Thanks!