static void Main(string[] args) { Subject subject = new BadMan(); Observer police = new PoliceMan(subject as BadMan); Observer citizen = new Citizen(subject as BadMan); Observer wife = new Wife(subject as BadMan); BadMan badman = subject as BadMan; badman.RunAway("广西"); Console.WriteLine(); badman.RunAway("海南"); Console.WriteLine(); subject.Detach(wife); badman.RunAway("美国"); subject.Detach(police); Console.WriteLine(); badman.RunAway("澳大利亚"); Console.WriteLine(); subject.Detach(citizen); badman.RunAway("月球"); }