HashtableからArray配列 C#

string[] myKeys = myHashtable.Keys;
Debug.Log(myKeys);

myKeysはなぜか空

このサイトを参考にした
URL: http://www.java2s.com/Tutorial/CSharp/0220__Data-Structure/CopythekeysfromHashtableintoanarrayusingtheCopyTomethodandthendisplaythearraycontents.htm

string[] myKeys = new string[5];
myHashtable.Keys.CopyTo(myKeys, 0);