c# - AccessViolationException while adding item to a list -

i developing windows phone 8.0 app in vs2010

and in point , decided make 2 classes (player,game)

game.cs

public class game {     public string name { get; set; }     public bool[] levelsunlocked { get; set; }     public bool firsttimeplaying { get; set; }      public game(int numoflevels)     {         this.firsttimeplaying = true;         this.levelsunlocked = new bool[numoflevels];     } } 

player.cs

 public class player     {         public int id { get; set; }     public string firstname{ get;  set; }     public string lastname { get; set; }     public int age { get; set; }     public int rank { get; set; }     public int points { get; set; }     public string rankdescreption { get; set; }     public uri avatar { get; set; }   public list<game> games;          public player()         {             game hourglass = new game(6);             game commonnumbers = new game(11);              games.add(hourglass);             games.add(commonnumbers);          } } 

when debug , app crashes @ line : games.add(hourglass); because of accessviolationexception, don't see problem of adding item list .

so ?

you must initialize list before using it.

this:

public list<game> games; 

..needs this:

public list<game> games = new list<game>(); 

i surprised getting accessviolationexception.. have expected nullreferenceexception.