/// <summary>Checks whether <paramref name="enumValue"/> is of the enumeration type <typeparamref name="TEnum"/> and defined within this type.</summary>
/// <remarks>
/// When successful, the value is returned as a <c>Nullable</c> of the specified type for direct assignment.
/// </remarks>
/// <exception cref="ArgumentException"> If <paramref name="enumValue"/> is not of the specified type. </exception>
/// <exception cref="ArgumentOutOfRangeException"> If <paramref name="enumValue"/> has a numeric value that is not completely defined within its
/// enumeration type. For flag types, every bit must correspond to at least one enumeration value. </exception>
public static TEnum?CheckValidEnumValueAndType <TEnum> ([InvokerParameterName] string argumentName, object enumValue)
where TEnum : struct
{
if (enumValue == null)
{
return(default(TEnum?));
}
if (!(enumValue is TEnum))
{
throw CreateArgumentTypeException(argumentName, enumValue.GetType(), typeof(TEnum));
}
if (!EnumUtility.IsValidEnumValue(enumValue))
{
throw CreateEnumArgumentOutOfRangeException(argumentName, enumValue);
}
return((TEnum?)enumValue);
}
/// <summary>Checks whether <paramref name="enumValue"/> is of the enumeration type <typeparamref name="TEnum"/>, is defined within this
/// type, and is not a null reference.</summary>
/// <remarks>
/// When successful, the value is returned as the specified type for direct assignment.
/// </remarks>
/// <exception cref="ArgumentNullException"> If <paramref name="enumValue"/> is a null reference. </exception>
/// <exception cref="ArgumentException"> If <paramref name="enumValue"/> is not of the specified type. </exception>
/// <exception cref="ArgumentOutOfRangeException"> If <paramref name="enumValue"/> has a numeric value that is not completely defined within its
/// enumeration type. For flag types, every bit must correspond to at least one enumeration value. </exception>
public static TEnum CheckValidEnumValueAndTypeAndNotNull <TEnum> (
[InvokerParameterName] string argumentName,
[AssertionCondition(AssertionConditionType.IS_NOT_NULL)] object enumValue)
where TEnum : struct
{
if (enumValue == null)
{
throw new ArgumentNullException(argumentName);
}
if (!(enumValue is TEnum))
{
throw CreateArgumentTypeException(argumentName, enumValue.GetType(), typeof(TEnum));
}
if (!EnumUtility.IsValidEnumValue(enumValue))
{
throw CreateEnumArgumentOutOfRangeException(argumentName, enumValue);
}
return((TEnum)enumValue);
}
/// <summary> Converts <paramref name="value"/> into an <see cref="Enum"/> value. </summary>
/// <param name="context"> An <see cref="ITypeDescriptorContext"/> that provides a format context. </param>
/// <param name="culture"> The <see cref="CultureInfo"/> to use as the current culture. </param>
/// <param name="value"> The source value. </param>
/// <returns> An <see cref="Enum"/> value. </returns>
/// <exception cref="NotSupportedException"> The conversion could not be performed. </exception>
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
{
// ReSharper disable ConditionIsAlwaysTrueOrFalse
if (_isNullable && (value == null || (value is string) && string.IsNullOrEmpty((string)value)))
{
return(null);
}
if (!(value is string))
{
if (value != null && _underlyingType == value.GetType())
{
if (!EnumUtility.IsValidEnumValue(UnderlyingEnumType, value))
{
throw new ArgumentOutOfRangeException(string.Format("The value {0} is not supported for enumeration '{1}'.", value, UnderlyingEnumType.FullName), (Exception)null);
}
return(Enum.ToObject(UnderlyingEnumType, value));
}
}
return(base.ConvertFrom(context, culture, value));
// ReSharper restore ConditionIsAlwaysTrueOrFalse
}