static void Main(string[] args) { PlayContext context = new PlayContext(); Console.WriteLine("上海滩:"); context.PlayText = "T 500 O 2 E 0.5 G 0.5 A 3 E 0.5 G 0.5 D 3 E 0.5 G 0.5 A 0.5 O 3 C 1 O 2 A 0.5 G 1 C 0.5 E 0.5 D 3 "; AbstractExpression expression = null; try { while (context.PlayText.Length > 0) { string str = context.PlayText.Substring(0, 1); switch (str) { case "O": expression = new Scale(); break; case "T": expression = new Speed(); break; case "C": case "D": case "E": case "F": case "G": case "A": case "B": case "P": expression = new Note(); break; } expression.Interpret(context); } } catch (Exception ex) { Console.WriteLine(ex.Message); } Console.WriteLine(); }