c# - 确定枚举中缺少哪些标志

Question

假设我有下面的枚举:

[Flags]
public enum NotifyType
{

    None = 0,
    Window = 1 << 0,
    Sound = 1 << 1,
    Flash = 1 << 2,
    MobileSound = 1 << 3,
    MobilePush = 1 << 4
}

考虑两个枚举:

var myenums = Window | Sound | Flash;


//var possibleUpdate = Window | MobilePush;

void UpdateMyEnums(NotifyType possibleUpdate)
{
    //Does myenums contain all the flags in 'possibleUpdate'?  If not add
    //the missing flags to myenums

}

与 possibleUpdate 相比，如何确定 myenums 变量不包含 NotifyType.MobilePush 值？我是否必须针对 myenums 测试 possibleUpdate 中的每个标志？

我在 .NET 4.0 上使用 C#

Answer 1

if (myenums & possibleUpdate != possibleUpdate)
    //not a possible update

要获取 myenums 中不需要的标志:

NotifyType missing = (~(myenums ^ wanted) ^ wanted) & (myenums | wanted);