How do I select all items in a listbox on checkbox checked?

Question

I need to select all items in a ListBox when a CheckBox is clicked. Is it possible to select all items in the ListBox using a single line of code? Or will I have to loop thr

Answer 1

In my case i had 10k+ items, the basic loop method was taking almost a minute to complete. Using @DiogoNeves answer and extending it i wanted to be able to select all (Ctrl+A) & copy (Ctrl+C). i handled this 2 ways. i used the BeginUpdate() and EndUpdate() to defer drawing but i also added a direct copy all (Ctrl+Shift+C) which doesn't even bother to select the items before copying.

private static void HandleListBoxKeyEvents(object sender, KeyEventArgs e)
{
    var lb = sender as ListBox;
    // if copy
    if (e.Control && e.KeyCode == Keys.C)
    {
        // if shift is also down, copy everything!
        var itemstocopy = e.Shift ? lb.Items.Cast