enum

//枚举类型是一种的值类型，它用于声明一组命名的常数。 
//(1)枚举的声明:枚举声明用于声明新的枚举类型。 
访问修辞符 enum 枚举名:基础类型 
{ 
    枚举成员 
} 
//示例: 
public enum TimeofDay:uint 
{ 
    Morning, 
    Afternoon, 
    Evening 
} 
//Morning的值为0,Afternoon的值为1,Evening的值为2。 
class Test 

{ 
    static void WriteGreeting(TimeofDay timeofDay) 
    { 
        switch(timeofDay) 
        { 
            case TimeofDay.Morning: 
            Console.WriteLine("good morning"); 
            break; 
            case TimeofDay.Afternoon: 
            Console.WriteLine("good afternoon"); 
            break; 
            case TimeofDay.Evening: 
            Console.WriteLine("good evening"); 
            break; 
        } 
    } 
    static void Main() 
    { 
        WriteGreeting(TimeofDay.Morning); 
        WriteGreeting(TimeofDay.Evening); 
        WriteGreeting(TimeofDay.Afternoon); 
    } 
}