In my query string, I have an age variable ?age=New_Born
.
Is there a way I can check if this string value New_Born
is in my Enum list
You can use the TryParse method that returns true if it successful:
Age age;
if(Enum.TryParse<Age>("myString", out age))
{
//Here you can use age
}
I know this is an old thread, but here's a slightly different approach using attributes on the Enumerates and then a helper class to find the enumerate that matches.
This way you could have multiple mappings on a single enumerate.
public enum Age
{
[Metadata("Value", "New_Born")]
[Metadata("Value", "NewBorn")]
New_Born = 1,
[Metadata("Value", "Toddler")]
Toddler = 2,
[Metadata("Value", "Preschool")]
Preschool = 4,
[Metadata("Value", "Kindergarten")]
Kindergarten = 8
}
With my helper class like this
public static class MetadataHelper
{
public static string GetFirstValueFromMetaDataAttribute<T>(this T value, string metaDataDescription)
{
return GetValueFromMetaDataAttribute(value, metaDataDescription).FirstOrDefault();
}
private static IEnumerable<string> GetValueFromMetaDataAttribute<T>(T value, string metaDataDescription)
{
var attribs =
value.GetType().GetField(value.ToString()).GetCustomAttributes(typeof (MetadataAttribute), true);
return attribs.Any()
? (from p in (MetadataAttribute[]) attribs
where p.Description.ToLower() == metaDataDescription.ToLower()
select p.MetaData).ToList()
: new List<string>();
}
public static List<T> GetEnumeratesByMetaData<T>(string metadataDescription, string value)
{
return
typeof (T).GetEnumValues().Cast<T>().Where(
enumerate =>
GetValueFromMetaDataAttribute(enumerate, metadataDescription).Any(
p => p.ToLower() == value.ToLower())).ToList();
}
public static List<T> GetNotEnumeratesByMetaData<T>(string metadataDescription, string value)
{
return
typeof (T).GetEnumValues().Cast<T>().Where(
enumerate =>
GetValueFromMetaDataAttribute(enumerate, metadataDescription).All(
p => p.ToLower() != value.ToLower())).ToList();
}
}
you can then do something like
var enumerates = MetadataHelper.GetEnumeratesByMetaData<Age>("Value", "New_Born");
And for completeness here is the attribute:
[AttributeUsage(AttributeTargets.Field, Inherited = false, AllowMultiple = true)]
public class MetadataAttribute : Attribute
{
public MetadataAttribute(string description, string metaData = "")
{
Description = description;
MetaData = metaData;
}
public string Description { get; set; }
public string MetaData { get; set; }
}
You can use the Enum.TryParse method:
Age age;
if (Enum.TryParse<Age>("New_Born", out age))
{
// You now have the value in age
}
I've got a handy extension method that uses TryParse, as IsDefined is case-sensitive.
public static bool IsParsable<T>(this string value) where T : struct
{
return Enum.TryParse<T>(value, true, out _);
}
You can use:
Enum.IsDefined(typeof(Age), youragevariable)
You should use Enum.TryParse to achive your goal
This is a example:
[Flags]
private enum TestEnum
{
Value1 = 1,
Value2 = 2
}
static void Main(string[] args)
{
var enumName = "Value1";
TestEnum enumValue;
if (!TestEnum.TryParse(enumName, out enumValue))
{
throw new Exception("Wrong enum value");
}
// enumValue contains parsed value
}