Copies the entire collection into an existing array of objects at a specified location within the array.
public void CopyTo(
The object array in which the items from the collection are copied to.
The location within the destination array to copy the items from the collection to.
You can use this method to combine the items from multiple collections into a single array. You can then use this array to populate the contents of another ListBox control using the AddRange method of the ListBox.ObjectCollection class.
ListBox.ObjectCollection ClassSystem.Windows.Forms Namespace