Hold content efficiently

Question

So I have got this class called TypingKeyboard. It's a class that draws a string on the screen as if it is typed by someone, with sounds. I use this for many things, for example in the main menu, credits and the game itself.

class TypingKeyboard
{
    SoundEffect foo;

    public TypingKeyboard(string text, int intervalBetweenKeys, blah blah blah){}

    public void LoadContent(ContentManager content)
    {
        foo = Content.Load<SoundEffect>("keysoundthinggy");
    }
}

In order to hear sounds you need to load the sounds, and store them. This happens for every instance of the class I have.

So every time you make this class, you need to call LoadContent and it loads the SoundEffect to the RAM. This is not very efficient since I always use the same sounds.

Is there a way that I can create a class that you need to make an instance of once and then can call the sounds from "anywhere" I want?

Like this:

// I need to play the sound!
TypingKeyboardData.Foo.Play();

Answer 1

Use the lazy singleton pattern:

public class TypingKeyboardData
{
    private static readonly Lazy<TypingKeyboardData> _instance
        = new Lazy<TypingKeyboardData>(() => new TypingKeyboardData());
    // private to prevent direct instantiation.
    private TypingKeyboardData()
    {
    }
    // accessor for instance
    public static TypingKeyboardData Instance
    {
        get
        {
            return _instance.Value;
        }
    }

    // Add all required instance methods below
}

More here.