Deserialize to existing objects using standard formatter

Established deserialization .net always creates a graph of new objects. This is not always convenient.

• For example, if objects contain non-serializable data, open handles, and so on.
• Objects that do not fall into the serialization can have links to readable objects, etc. This is especially true if your assembly is used by someone else, and you can not solve all such cases with the help of the correct design.
• And in the end, for the sake of a small Undo completely re-create objects irrational.

The search did not give a ready answer. There are not very simple solutions using protobuf and other third-party serializers, but this is not always applicable.
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The task as a whole is simple, and my solution is not something outstanding, but on the other hand, it will be easier for those who face a similar problem for the first time.



Serialization is done as usual. The following 2 classes will solve the problem during deserialization.

[Serializable] public class RealObjectHelper : IObjectReference, ISerializable { Object m_realObject; virtual object getObject(ObjectId id) { //     , return id.GetObject(); } public RealObjectHelper(SerializationInfo info, StreamingContext context) { ObjectId id = (ObjectId)info.GetValue("ID", typeof(ObjectId)); m_realObject = getObject(id); if(m_realObject == null) return; Type t = m_realObject.GetType(); MemberInfo[] members = FormatterServices.GetSerializableMembers(t, context); List<MemberInfo> deserializeMembers = new List<MemberInfo>(members.Length); List<object> data = new List<object>(members.Length); foreach(MemberInfo mi in members) { Type dataType = null; if(mi.MemberType == MemberTypes.Field) { FieldInfo fi = mi as FieldInfo; dataType = fi.FieldType; } else if(mi.MemberType == MemberTypes.Property){ PropertyInfo pi = mi as PropertyInfo; dataType = pi.PropertyType; } try { if(dataType != null){ data.Add(info.GetValue(mi.Name, dataType)); deserializeMembers.Add(mi); } } catch (SerializationException) { //some fiels are missing, new version, skip this fields } } FormatterServices.PopulateObjectMembers(m_realObject, deserializeMembers.ToArray(), data.ToArray()); } public object GetRealObject( StreamingContext context ) { return m_realObject; } [SecurityPermission(SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.SerializationFormatter)] public void GetObjectData(SerializationInfo info, StreamingContext context) { } } public class RealObjectBinder: SerializationBinder { String assemVer; String typeVer; public RealObjectBinder(String asmName, String typeName) { assemVer = asmName; typeVer = typeName; } public override Type BindToType( String assemblyName, String typeName ) { Type typeToDeserialize = null; if ( assemblyName.Equals( assemVer ) && typeName.Equals( typeVer ) ) { return typeof(RealObjectHelper); } typeToDeserialize = Type.GetType( String.Format( "{0}, {1}", typeName, assemblyName ) ); return typeToDeserialize; } } 

When deserializing, you must install Binder, which will create a wrapper for deserialization into your existing object.

  BinaryFormatter bf = new BinaryFormatter(null, context); bf.Binder = new RealObjectBinder(YourType.Assembly.FullName, YourType.FullName); bf.Deserialize(memStream);