/// <summary>
/// Retrieves the name of the constant in the specified enumeration that has the specified value.
/// </summary>
/// <param name="enumType">An enumeration type.</param>
/// <param name="value">The value of a particular enumerated constant in terms of its underlying type.</param>
/// <returns> A string containing the name of the enumerated constant in enumType whose value is value, or null if no such constant is found.</returns>
/// <exception cref="ArgumentException"> enumType is not an System.Enum. -or- value is neither of type enumType nor does it have the same underlying type as enumType.</exception>
public static string GetName(Type enumType, object value)
{
if (enumType == null)
{
throw new ArgumentNullException(nameof(enumType));
}
if (value == null)
{
throw new ArgumentNullException(nameof(value));
}
Type valueType = value.GetType();
if (!valueType.IsEnum && !Type2.IsIntegerNumber(valueType))
{
throw new ArgumentException("The specified value should be enum base or an integer number", nameof(value));
}
int length;
bool isFlags;
Type underlyingType;
var valuesAndNames = GetValuesAndNames(enumType, out length, out isFlags, out underlyingType);
object numValue = Convert.ChangeType(value, underlyingType, null);
//cycle through the enum values
foreach (var item in valuesAndNames)
{
//if value matches return the name
if (numValue.Equals(item.ValueAsNumber))
{
return(item.Name);
}
}
//if there is no match return null
return(null);
}
private static string InternalValuesFormat(Type enumType, object value)
{
int length;
bool isFlags;
Type underlyingType;
var valuesAndNames = GetValuesAndNames(enumType, out length, out isFlags, out underlyingType)
.OrderBy(a => a.ValueAsNumber)
.ToArray();
if (valuesAndNames.Length == 0)
{
return(value.ToString());
}
if (Type2.IsSignedNumber(underlyingType))
{
return(InternalSignedValuesFormat(enumType, value, valuesAndNames));
}
else
{
return(InternalUnsignedValuesFormat(enumType, value, valuesAndNames));
}
}