C#位操作与枚举的应用

看到代码里有用位操作来判断条件的，以前没有这么用过，做个笔记:

int add = 2;
int modify = 4;
int delete = 8;

Console.WriteLine((add | modify | delete) & add); //2
Console.WriteLine((add | modify | delete) & modify); //4
Console.WriteLine((add | modify | delete) & delete); //8

但是直接使用整数进行位操作，可读性不太好。

其实C#里有枚举，也可以实现，但是C#的枚举可读性应该更好

[Flags]
enum OperatingAuthorization
{
    Add = 2,
    Modify = 4,
    Delete = 8
}

OperatingAuthorization allOperating = OperatingAuthorization.Add | OperatingAuthorization.Modify | OperatingAuthorization.Delete;
Console.WriteLine(allOperating & OperatingAuthorization.Add); //Add

这个可以用于判断权限是否存在，
如allOperating & OperatingAuthorization.Add == OperatingAuthorization.Add，则可确定allOperating包含OperatingAuthorization.Add
这里可以假定allOperating是从数据库取出来的