Question

I am looking to have a C# application implement the Konami Code to display an Easter Egg. http://en.wikipedia.org/wiki/Konami_Code

What is the best way to do this?

This is in a standard C# windows forms app.

Answer 1

In windows forms I would have a class that knows what the sequence is and holds the state of where you are in the sequence. Something like this should do it.

using System; using System.Collections.Generic; using System.Windows.Forms;  namespace WindowsFormsApplication3 {     public class KonamiSequence {          List<Keys> Keys = new List<Keys>{System.Windows.Forms.Keys.Up, System.Windows.Forms.Keys.Up,                                         System.Windows.Forms.Keys.Down, System.Windows.Forms.Keys.Down,                                         System.Windows.Forms.Keys.Left, System.Windows.Forms.Keys.Right,                                         System.Windows.Forms.Keys.Left, System.Windows.Forms.Keys.Right,                                         System.Windows.Forms.Keys.B, System.Windows.Forms.Keys.A};         private int mPosition = -1;          public int Position {             get { return mPosition; }             private set { mPosition = value; }         }          public bool IsCompletedBy(Keys key) {              if (Keys[Position + 1] == key) {                 // move to next                 Position++;             }             else if (Position == 1 && key == System.Windows.Forms.Keys.Up) {                 // stay where we are             }             else if (Keys[0] == key) {                 // restart at 1st                 Position = 0;             }             else {                 // no match in sequence                 Position = -1;             }              if (Position == Keys.Count - 1) {                 Position = -1;                 return true;             }              return false;         }     } } 

To use it, you would need something in your Form’s code responding to key up events. Something like this should do it:

    private KonamiSequence sequence = new KonamiSequence();      private void Form1_KeyUp(object sender, KeyEventArgs e) {         if (sequence.IsCompletedBy(e.KeyCode)) {             MessageBox.Show('KONAMI!!!');         }     } 

Hopefully that’s enough to give you what you need. For WPF you will need slight differences is very similar (see edit history #1).

EDIT: updated for winforms instead of wpf.