I know that:
String test = "test";
ListBox.Items.Add(test);
or
String test = "test";
int index = 1;
ListBox.Items.Insert(index, String);
adds the String in a ListBox, but I want to insert ListBoxItem, how to? previously I learn that
var contentToString = (String)ListBoxItem.Content;
simply converts ListBoxItem to String, but I couldn't do the opposite to convert String to ListBoxItem