.NET Standard 2.0
dotnet add package DouglasDwyer.RoyalXml --version
NuGet\Install-Package DouglasDwyer.RoyalXml -Version
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="DouglasDwyer.RoyalXml" Version="" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add DouglasDwyer.RoyalXml --version
#r "nuget: DouglasDwyer.RoyalXml,"
#r directive can be used in F# Interactive, C# scripting and .NET Interactive. Copy this into the interactive tool or source code of the script to reference the package.
// Install DouglasDwyer.RoyalXml as a Cake Addin
#addin nuget:?package=DouglasDwyer.RoyalXml&version=

// Install DouglasDwyer.RoyalXml as a Cake Tool
#tool nuget:?package=DouglasDwyer.RoyalXml&version=

Nuget Downloads


RoyalXml is a simple XML serializer for .NET that supports polymorphism, multidimensional arrays, and collections.


RoyalXml can be obtained as a Nuget package. To import it into your project, either download DouglasDwyer.RoyalXml from the Visual Studio package manager or run the command Install-Package DouglasDwyer.RoyalXml using the package manager console.

How to use

Usage of RoyalXml with the default ruleset is quite simple. The following code snippet serializes and then deserializes an object using the default serialization ruleset:

RoyalXmlSerializer serializer = new RoyalXmlSerializer();
Dictionary<string, string> c = new Dictionary<string, string>() { { "hi", "bye" }, { "why", "cry" } };
string xml = serializer.Serialize(c);
Dictionary<string, string> d = serializer.Deserialize<Dictionary<string, string>>(xml);

Because different serializers can have different rulesets, it is necessary that serializers be instance-based and not static or singletons.

The default serialization ruleset

By default, RoyalXml comes with a builtin serialization ruleset. The default ruleset supports primitive types, objects in hierarchies, polymorphism, multidimensional arrays, collections, and dictionaries. Object references are not preserved during serialization, though it is possible to implement such behavior. This means that cyclical references are also unsupported.

Serialization rulesets

To perform serialization/deserialization in a configurable manner, RoyalXml centers around the use of serialization rulesets, which are passed into the constructor of RoyalXmlSerializer. If no ruleset is specified, then RoyalXmlSerializer.DefaultRuleset is used. Serialization rulesets are collections of RoyalSerializationRules which specify how to convert various types (and potentially their derived types). An example of a serialization rule, the ICollectionSerializationRule class, is given below:

public class ICollectionSerializationRule : RoyalSerializationRule
    public override Type SupportedType => typeof(ICollection<>);

    public override object Deserialize(XElement node, Type type, RoyalXmlSerializer serializer)
        Type collectionType = type.GetInterfaces().Where(generic => generic.IsGenericType && generic.GetGenericTypeDefinition() == typeof(ICollection<>)).Single();
        object collection = Activator.CreateInstance(type);
        MethodInfo addToCollectionMethod = collectionType.GetMethod("Add", BindingFlags.Public | BindingFlags.Instance);
        foreach(XElement subnode in node.Nodes())
            string subType = subnode.Attribute("Type").Value;
            if (subType == "null")
                addToCollectionMethod.Invoke(collection, new object[] { null });
                addToCollectionMethod.Invoke(collection, new object[] { ReadObjectXml(subnode, Type.GetType(subType), serializer) });
        return collection;

    public override void Serialize(object data, XmlWriter writer, RoyalXmlSerializer serializer)
        foreach(object o in (IEnumerable)data)
            if(o is null)
                writer.WriteAttributeString("Type", "null");
                writer.WriteAttributeString("Type", o.GetType().AssemblyQualifiedName);
                WriteObjectXml(o, writer, serializer);

The SupportedType property specifies that this rule can be applied to any ICollection<>. Note that this is a generic type - generic types like these are supported. During serialization/deseriation, the elements of the collection are enumerated, and WriteObjectXml and ReadObjectXml are called to serialize/deserialize subobjects. These methods make calls to the RoyalXmlSerializer, which determines the best serialization rule to use for any given object/type.

The best-fitting serialization rule

When a RoyalXmlSerializer is asked to serialize/deserialize a given type, it iterates through the type's inheritance hierarchy, attempting to find a type contained in the serialization ruleset. The serializer attempts to match a best-fitting rule by checking the given type's inheritance chain in the following order:

  • If the given type matches a rule's type, that rule is used
  • If the given type is generic, and a rule's type matches the generic definition, that rule is used
  • If one of the given type's interfaces matches a rule's type, that rule is used
  • If one of the given type's interfaces is generic, and a rule's type matches the generic definition, that rule is used
  • For each of the given type's base types, if the base type matches a rule, then that rule is used. If the base type is generic, and the generic type definition matches a rule, then that rule is used.

These rules make RoyalXml quite powerful, as it is easy to customize or extend behavior to various classes.

Product Versions
.NET net5.0 net5.0-windows net6.0 net6.0-android net6.0-ios net6.0-maccatalyst net6.0-macos net6.0-tvos net6.0-windows net7.0 net7.0-android net7.0-ios net7.0-maccatalyst net7.0-macos net7.0-tvos net7.0-windows
.NET Core netcoreapp2.0 netcoreapp2.1 netcoreapp2.2 netcoreapp3.0 netcoreapp3.1
.NET Standard netstandard2.0 netstandard2.1
.NET Framework net461 net462 net463 net47 net471 net472 net48
MonoAndroid monoandroid
MonoMac monomac
MonoTouch monotouch
Tizen tizen40 tizen60
Xamarin.iOS xamarinios
Xamarin.Mac xamarinmac
Xamarin.TVOS xamarintvos
Xamarin.WatchOS xamarinwatchos
Compatible target framework(s)
Additional computed target framework(s)
Learn more about Target Frameworks and .NET Standard.
  • .NETStandard 2.0

    • No dependencies.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last updated 404 10/10/2020 399 10/10/2020
1.1.0 391 8/2/2020

Fixed a glitch with the serialization of arrays.