System.Runtime.Serialization.EnumDataContract.EnumDataContract.WriteEnumValue C# (CSharp) Method

        internal void WriteEnumValue(XmlWriterDelegator writer, object value)
        {
            long longValue = IsULong ? (long)Convert.ToUInt64(value, null) : Convert.ToInt64(value, null);
            for (int i = 0; i < Values.Count; i++)
            {
                if (longValue == Values[i])
                {
                    writer.WriteString(ChildElementNames[i].Value);
                    return;
                }
            }
            if (IsFlags)
            {
                int zeroIndex = -1;
                bool noneWritten = true;
                for (int i = 0; i < Values.Count; i++)
                {
                    long current = Values[i];
                    if (current == 0)
                    {
                        zeroIndex = i;
                        continue;
                    }
                    if (longValue == 0)
                        break;
                    if ((current & longValue) == current)
                    {
                        if (noneWritten)
                            noneWritten = false;
                        else
                            writer.WriteString(DictionaryGlobals.Space.Value);

                        writer.WriteString(ChildElementNames[i].Value);
                        longValue &= ~current;
                    }
                }
                // enforce that enum value was completely parsed
                if (longValue != 0)
                    throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(XmlObjectSerializer.CreateSerializationException(SR.Format(SR.InvalidEnumValueOnWrite, value, DataContract.GetClrTypeFullName(UnderlyingType))));

                if (noneWritten && zeroIndex >= 0)
                    writer.WriteString(ChildElementNames[zeroIndex].Value);
            }
            else
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(XmlObjectSerializer.CreateSerializationException(SR.Format(SR.InvalidEnumValueOnWrite, value, DataContract.GetClrTypeFullName(UnderlyingType))));
        }