System.Xml.Serialization.TypeScope.PopulateMemberInfos C# (CSharp) Method

        private static void PopulateMemberInfos(StructMapping structMapping, MemberMapping[] mappings, System.Collections.Generic.Dictionary<string, MemberInfo> memberInfos)
        {
            memberInfos.Clear();
            for (int i = 0; i < mappings.Length; ++i)
            {
                memberInfos[mappings[i].Name] = mappings[i].MemberInfo;
                if (mappings[i].ChoiceIdentifier != null)
                    memberInfos[mappings[i].ChoiceIdentifier.MemberName] = mappings[i].ChoiceIdentifier.MemberInfo;
                if (mappings[i].CheckSpecifiedMemberInfo != null)
                    memberInfos[mappings[i].Name + "Specified"] = mappings[i].CheckSpecifiedMemberInfo;
            }

            // The scenario here is that user has one base class A and one derived class B and wants to serialize/deserialize an object of B.
            // There's one virtual property defined in A and overrided by B. Without the replacing logic below, the code generated will always
            // try to access the property defined in A, rather than B.
            // The logic here is to:
            // 1) Check current members inside memberInfos dictionary and figure out whether there's any override or new properties defined in the derived class.
            //    If so, replace the one on the base class with the one on the derived class.
            // 2) Do the same thing for the memberMapping array. Note that we need to create a new copy of MemberMapping object since the old one could still be referenced
            //    by the StructMapping of the baseclass, so updating it directly could lead to other issues.
            Dictionary<string, MemberInfo> replaceList = null;
            MemberInfo replacedInfo = null;
            foreach (KeyValuePair<string, MemberInfo> pair in memberInfos)
            {
                if (ShouldBeReplaced(pair.Value, structMapping.TypeDesc.Type, out replacedInfo))
                {
                    if (replaceList == null)
                    {
                        replaceList = new Dictionary<string, MemberInfo>();
                    }

                    replaceList.Add(pair.Key, replacedInfo);
                }
            }

            if (replaceList != null)
            {
                foreach (KeyValuePair<string, MemberInfo> pair in replaceList)
                {
                    memberInfos[pair.Key] = pair.Value;
                }
                for (int i = 0; i < mappings.Length; i++)
                {
                    MemberInfo mi;
                    if (replaceList.TryGetValue(mappings[i].Name, out mi))
                    {
                        MemberMapping newMapping = mappings[i].Clone();
                        newMapping.MemberInfo = mi;
                        mappings[i] = newMapping;
                    }
                }
            }
        }