Serializing Generics

The following exceptions are thrown when you try to serialize a any of the types (except for List) in the System.Collections.Generic namespace:

A first chance exception of type 'System.NotSupportedException' occurred in System.Xml.dll
System.NotSupportedException: The type System.Collections.Generic.Dictionary`2[[System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] is not supported because it implements IDictionary.

A first chance exception of type 'System.InvalidOperationException' occurred in System.Xml.dll
System.InvalidOperationException: You must implement a default accessor on System.Collections.Generic.Queue`1[[System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] because it inherits from ICollection.
at System.Xml.Serialization.TypeScope.GetDefaultIndexer(Type type, String memberInfo)
at System.Xml.Serialization.TypeScope.ImportTypeDesc(Type type, MemberInfo memberInfo, Boolean directReference)
at System.Xml.Serialization.TypeScope.GetTypeDesc(Type type, MemberInfo source, Boolean directReference, Boolean throwOnError)
at System.Xml.Serialization.ModelScope.GetTypeModel(Type type, Boolean directReference)
at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping(Type type, XmlRootAttribute root, String defaultNamespace)
at System.Xml.Serialization.XmlSerializer..ctor(Type type, String defaultNamespace)
at System.Xml.Serialization.XmlSerializer..ctor(Type type)

A way around this problem is to implement the IXmlSerializable interface.

The following classes will allow you serialize generic types to XML in .NET 2.0:

• SerializableDictionary<T>
• SerializableLinkedList<T>
• SerializableQueue<T>
• SerializableSortedDictionary<T>
• SerializableSortedList<T>
• SerializableStack<T>

You can download the library's source code here.

The previous classes use the SerializableGenerics helper class which constructs the element name based on the key-value pair node:

/*
 * SerializableGenerics
 * Copyright (c) 2009, Eduardo Sanchez-Ros
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

using System;

namespace SerializableGenerics
{
    public static class SerializableGenerics
    {
        private const string OF = "Of";

        /// <summary>
        /// Gets the key-value pair name
        /// </summary>
        /// <param name="tKey"></param>
        /// <param name="tValue"></param>
        /// <returns></returns>
        public static string GetKeyValuePairName(Type tKey, Type tValue)
        {
            // return key-value pair name
            return GetTypeName(tKey) + GetTypeName(tValue);
        }

        /// <summary>
        /// Returns the name of the type
        /// </summary>
        /// <param name="type">Type to generate the name from</param>
        /// <returns>The name of the type</returns>
        public static String GetTypeName(Type type)
        {
            String typeName;

            // Is type generic
            if (type.IsGenericType)
            {
                // Get type name - Generics 
                typeName = type.Name.Substring(0, type.Name.Length - 2);
                typeName += OF;

                // Get type's arguments
                Type[] types = type.GetGenericArguments();
                foreach (Type t in types)
                {
                    // Append type's name
                    typeName += GetTypeName(t);
                }
            }
            else if (type.IsArray)
            {
                // Compose array name as "ArrayOf" and get array element's type name
                typeName = type.BaseType.Name;
                typeName += OF;
                typeName += GetTypeName(type.GetElementType());
            }
            else
            {
                // Append type's name
                typeName = type.Name;
            }

            // return type's name
            return typeName;
        }
    }
}