我有一门课叫问题(复数)。在这个类中有一个名为Question(单数)的枚举,看起来像这样。

public enum Question
{
    Role = 2,
    ProjectFunding = 3,
    TotalEmployee = 4,
    NumberOfServers = 5,
    TopBusinessConcern = 6
}

在Questions类中,我有一个get(intfoo)函数,它为该foo返回Questions对象。有没有一种简单的方法可以从枚举中获取整数值,这样我就可以执行类似于Questions.get(Questions.Role)的操作?


当前回答

你应该使用我们可以在任何其他语言中使用的类型铸造。

如果枚举是这样的-

public enum Question
{
    Role = 2,
    ProjectFunding = 3,
    TotalEmployee = 4,
    NumberOfServers = 5,
    TopBusinessConcern = 6
}

你需要转换为int,然后这样做-

Question q = Question.Role;
.............
.............
int something = (int) q;

Re-

在C#中,有两种类型的铸件:

隐式转换(自动)-将较小的类型转换为较大的类型大小,如-

char->int->long->float->double

显式转换(手动)-将较大的类型转换为较小的类型,如-

double->float->long->int->char

更多信息可以在这里找到。

其他回答

Question question = Question.Role;
int value = (int) question;

将导致值==2。

为了确保枚举值存在,然后解析它,还可以执行以下操作。

// Fake Day of Week
string strDOWFake = "SuperDay";

// Real Day of Week
string strDOWReal = "Friday";

// Will hold which ever is the real DOW.
DayOfWeek enmDOW;

// See if fake DOW is defined in the DayOfWeek enumeration.
if (Enum.IsDefined(typeof(DayOfWeek), strDOWFake))
{
    // This will never be reached since "SuperDay"
    // doesn't exist in the DayOfWeek enumeration.
    enmDOW = (DayOfWeek)Enum.Parse(typeof(DayOfWeek), strDOWFake);
}
// See if real DOW is defined in the DayOfWeek enumeration.
else if (Enum.IsDefined(typeof(DayOfWeek), strDOWReal))
{
    // This will parse the string into it's corresponding DOW enum object.
    enmDOW = (DayOfWeek)Enum.Parse(typeof(DayOfWeek), strDOWReal);
}

// Can now use the DOW enum object.
Console.Write("Today is " + enmDOW.ToString() + ".");

Use:

Question question = Question.Role;
int value = question.GetHashCode();

这将导致值==2。

只有当枚举适合于int时,这才是真的。

int number = Question.Role.GetHashCode();

number的值应为2。

public enum Suit : int
{
    Spades = 0,
    Hearts = 1,
    Clubs = 2,
    Diamonds = 3
}

Console.WriteLine((int)(Suit)Enum.Parse(typeof(Suit), "Clubs"));

// From int
Console.WriteLine((Suit)1);

// From a number you can also
Console.WriteLine((Suit)Enum.ToObject(typeof(Suit), 1));

if (typeof(Suit).IsEnumDefined("Spades"))
{
    var res = (int)(Suit)Enum.Parse(typeof(Suit), "Spades");
    Console.Out.WriteLine("{0}", res);
}