namespace const_and_readonly{class Program{static void Main(string[] args){Console.WriteLine("Half a year have {0} Moths", Calendar.Moths/2); //直接類名.字段訪問const字段Calendar test1 = new Calendar();Console.WriteLine("Every year has {0} weeks and {1} days", test1._weeks, test1._days);//readonly字段通過實例訪問Calendar test2 = new Calendar(31, 4);Console.WriteLine("January has {0} weeks and {1} days", test2._weeks ,test2 ._days);Console.ReadKey();}}class Calendar{public const int Moths = 12; //const必須在聲明中初始化public readonly int _days=365; //readonly在聲明中初始化public readonly int _weeks;public Calendar() //readonly在構造函數內初始化{_weeks = 52;}public Calendar(int days,int weeks) //readonly在構造函數內初始化{_days = days;_weeks = weeks;}public void setvalue(int days,int weeks){// _days = days; 無法對只讀字段賦值//_weeks = weeks; 無法對只讀字段賦值}}