How to access random item in list?

1. Create an instance of Random class somewhere. Note that it's pretty important not to create a new instance each time you need a random number. You should reuse the old instance to achieve uniformity in the generated numbers. You can have a static field somewhere (be careful about thread safety issues):

   static Random rnd = new Random();

2. Ask the Random instance to give you a random number with the maximum of the number of items in the ArrayList:

   int r = rnd.Next(list.Count);

3. Display the string:

   MessageBox.Show((string)list[r]);

I usually use this little collection of extension methods:

public static class EnumerableExtension{    public static T PickRandom<T>(this IEnumerable<T> source)    {        return source.PickRandom(1).Single();    }    public static IEnumerable<T> PickRandom<T>(this IEnumerable<T> source, int count)    {        return source.Shuffle().Take(count);    }    public static IEnumerable<T> Shuffle<T>(this IEnumerable<T> source)    {        return source.OrderBy(x => Guid.NewGuid());    }}

For a strongly typed list, this would allow you to write:

var strings = new List<string>();var randomString = strings.PickRandom();

If all you have is an ArrayList, you can cast it:

var strings = myArrayList.Cast<string>();

You can do:

list.OrderBy(x => Guid.NewGuid()).FirstOrDefault()