Saya selalu suka menulis "enum kustom" saya sendiri. Daripada saya memiliki satu kelas yang sedikit lebih kompleks, tetapi saya dapat menggunakannya kembali:
public abstract class CustomEnum
{
private readonly string _name;
private readonly object _id;
protected CustomEnum( string name, object id )
{
_name = name;
_id = id;
}
public string Name
{
get { return _name; }
}
public object Id
{
get { return _id; }
}
public override string ToString()
{
return _name;
}
}
public abstract class CustomEnum<TEnumType, TIdType> : CustomEnum
where TEnumType : CustomEnum<TEnumType, TIdType>
{
protected CustomEnum( string name, TIdType id )
: base( name, id )
{ }
public new TIdType Id
{
get { return (TIdType)base.Id; }
}
public static TEnumType FromName( string name )
{
try
{
return FromDelegate( entry => entry.Name.Equals( name ) );
}
catch (ArgumentException ae)
{
throw new ArgumentException( "Illegal name for custom enum '" + typeof( TEnumType ).Name + "'", ae );
}
}
public static TEnumType FromId( TIdType id )
{
try
{
return FromDelegate( entry => entry.Id.Equals( id ) );
}
catch (ArgumentException ae)
{
throw new ArgumentException( "Illegal id for custom enum '" + typeof( TEnumType ).Name + "'", ae );
}
}
public static IEnumerable<TEnumType> GetAll()
{
var elements = new Collection<TEnumType>();
var infoArray = typeof( TEnumType ).GetFields( BindingFlags.Public | BindingFlags.Static );
foreach (var info in infoArray)
{
var type = info.GetValue( null ) as TEnumType;
elements.Add( type );
}
return elements;
}
protected static TEnumType FromDelegate( Predicate<TEnumType> predicate )
{
if(predicate == null)
throw new ArgumentNullException( "predicate" );
foreach (var entry in GetAll())
{
if (predicate( entry ))
return entry;
}
throw new ArgumentException( "Element not found while using predicate" );
}
}
Sekarang saya hanya perlu membuat enum yang ingin saya gunakan:
public sealed class SampleEnum : CustomEnum<SampleEnum, int>
{
public static readonly SampleEnum Element1 = new SampleEnum( "Element1", 1, "foo" );
public static readonly SampleEnum Element2 = new SampleEnum( "Element2", 2, "bar" );
private SampleEnum( string name, int id, string additionalText )
: base( name, id )
{
AdditionalText = additionalText;
}
public string AdditionalText { get; private set; }
}
Akhirnya saya bisa menggunakannya seperti yang saya inginkan:
static void Main( string[] args )
{
foreach (var element in SampleEnum.GetAll())
{
Console.WriteLine( "{0}: {1}", element, element.AdditionalText );
Console.WriteLine( "Is 'Element2': {0}", element == SampleEnum.Element2 );
Console.WriteLine();
}
Console.ReadKey();
}
Dan keluaran saya adalah:
Element1: foo
Is 'Element2': False
Element2: bar
Is 'Element2': True