如何检查一个枚举是否包含一个数字？

我有一个这样的 Enum:

 public enum PromotionTypes
{
Unspecified = 0,
InternalEvent = 1,
ExternalEvent = 2,
GeneralMailing = 3,
VisitBased = 4,
PlayerIntroduction = 5,
Hospitality = 6
}

我想检查这个 Enum 是否包含我给出的数字。例如: 当我给出4，Enum 包含它，所以我想返回 True，如果我给出7，在这个 Enum 中没有7，所以它返回 False。 我试过 Enum.IsDefine，但它只检查 String 值。 我该怎么做？

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最佳答案

The IsDefined method requires two parameters. The first parameter is the type of the enumeration to be checked. This type is usually obtained using a typeof expression. The second parameter is defined as a basic object. It is used to specify either the integer value or a string containing the name of the constant to find. The return value is a Boolean that is true if the value exists and false if it does not.

enum Status
{
OK = 0,
Warning = 64,
Error = 256
}


static void Main(string[] args)
{
bool exists;


// Testing for Integer Values
exists = Enum.IsDefined(typeof(Status), 0);     // exists = true
exists = Enum.IsDefined(typeof(Status), 1);     // exists = false


// Testing for Constant Names
exists = Enum.IsDefined(typeof(Status), "OK");      // exists = true
exists = Enum.IsDefined(typeof(Status), "NotOK");   // exists = false
}

SOURCE

小开

Try this:

IEnumerable<int> values = Enum.GetValues(typeof(PromotionTypes))
.OfType<PromotionTypes>()
.Select(s => (int)s);
if(values.Contains(yournumber))
{
//...
}
小开

You should use Enum.IsDefined.

I tried Enum.IsDefine but it only check the String value.

I'm 100% sure it will check both string value and int(the underlying) value, at least on my machine.

小开

Maybe you want to check and use the enum of the string value:

string strType;
if(Enum.TryParse(strType, out MyEnum myEnum))
{
// use myEnum
}
小开

I use Enums.NET package.

public enum PromotionTypes
{
Unspecified = 0,
InternalEvent = 1,
ExternalEvent = 2,
GeneralMailing = 3,
VisitBased = 4,
PlayerIntroduction = 5,
Hospitality = 6
}


((PromotionTypes)4).IsValid() == true;
((PromotionTypes)7).IsValid() == false;

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