有时您有一个MyEnum类型的对象。喜欢

var MyEnumType = typeof(MyEnum);

然后：

Enum.ToObject(typeof(MyEnum), 3)

从int：

YourEnum foo = (YourEnum)yourInt;

从字符串：

YourEnum foo = (YourEnum) Enum.Parse(typeof(YourEnum), yourString);

// The foo.ToString().Contains(",") check is necessary for 
// enumerations marked with a [Flags] attribute.
if (!Enum.IsDefined(typeof(YourEnum), foo) && !foo.ToString().Contains(","))
{
    throw new InvalidOperationException(
        $"{yourString} is not an underlying value of the YourEnum enumeration."
    );
}

从一个数字：

YourEnum foo = (YourEnum)Enum.ToObject(typeof(YourEnum), yourInt);

以以下示例为例：

int one = 1;
MyEnum e = (MyEnum)one;

简单地，可以将int强制转换为enum

 public enum DaysOfWeeks
    {
        Monday = 1,
        Tuesday = 2,
        Wednesday = 3,
        Thursday = 4,
        Friday = 5,
        Saturday = 6,
        Sunday = 7,
    } 

    var day= (DaysOfWeeks)5;
    Console.WriteLine("Day is : {0}", day);
    Console.ReadLine();

稍微偏离了最初的问题，但我找到了堆栈溢出问题的答案：从枚举中获取int值很有用。使用public const int财产创建一个静态类，允许您轻松收集一组相关的int常量，然后在使用它们时不必将它们强制转换为int。

public static class Question
{
    public static readonly int Role = 2;
    public static readonly int ProjectFunding = 3;
    public static readonly int TotalEmployee = 4;
    public static readonly int NumberOfServers = 5;
    public static readonly int TopBusinessConcern = 6;
}

显然，一些枚举类型的功能将丢失，但对于存储一堆数据库id常量来说，这似乎是一个非常整洁的解决方案。

只要投它：

MyEnum e = (MyEnum)3;

使用Enum.IsDefined检查它是否在范围内：

if (Enum.IsDefined(typeof(MyEnum), 3)) { ... }