Speeding up listbox insertion time

Question

I need to add 950 strings that are 2500 characters in length to a listbox. The method I am using below takes 2.5 seconds and ideally it needs to happen in less then 500ms.

Stopwatch sw = Stopwatch.StartNew();

listBox1.BeginUpdate();
listBox1.Items.AddRange(items.ToArray());
listBox1.EndUpdate();

sw.Stop();

What would be the best way to optimize the insertion time?

Thanks.

Answer 1

One thing you could try is changing this line:

listBox1.Items.AddRange(items.ToArray());

to something like this:

foreach (var item in items)
{
    listBox1.Items.Add(item);
}

That way, you do not have the overhead of creating a whole new array (the ToArray() call) before putting the items into your ListBox.