IBindingList And IBindingListView

How can it be?

List<T> doesn't implement IBindingList / IBindingListView - 开发者_C百科thus it cannot provide UI updates. You are going to need to change a few bits of code to suit the BindigList api.

UI notifications are done typically via events. This means, in this case, IBindingList and the ListChanged event; but also some side interfaces like IBindingListView, and a few other optional things for improved list adding etc. BindingList<T> supports pretty much everything you need, but as a consequence has some small overheads.

By contrast, List<T> deliberately provides none of this; it is a general purpose (and fast) dynamic list device, not an "observer" device.

Note you also typically need your type T to implement INotifyPropertyChanged if you want cell-by-cell updates; without this you can only get row-level updates (add, remove, etc).

For example:

using System;
using System.ComponentModel;
using System.Windows.Forms;

static class Program
{
    class Foo
    {
        public int A { get; set; }
        public string B { get; set; }
    }
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        using (var form = new Form())
        using (var grid = new DataGridView { Dock = DockStyle.Fill })
        using (var add = new Button { Dock = DockStyle.Bottom, Text = "add" })
        using (var remove = new Button { Dock = DockStyle.Top, Text = "remove" })
        {
            form.Controls.Add(grid);
            form.Controls.Add(add);
            form.Controls.Add(remove);
            var lst = new BindingList<Foo>();
            var rnd = new Random();
            add.Click += delegate
            {
                lst.Add(new Foo { A = rnd.Next(1, 6), B = "new" });
            };
            remove.Click += delegate
            {
                int index = 0;
                foreach (var row in lst)
                { // just to illustrate removing a row by predicate
                    if (row.A == 2) { lst.RemoveAt(index); break; }
                    index++;
                }
            };
            grid.DataSource = lst;
            Application.Run(form);
        }
    }
}