C# 3.0: Fill in objects with different behaviour in collections

I want to fill items in a combobox, each of them has different behaviour. Yes I know I could simply create 3 classes deriving from a base class. But my question is kind of "is there another way" and "what is possible". In Java one can do "new MyClass(){public void overriddenmethod(){...} }" but in C# we can not, can we?

Now I use a lambda to define a method on the fly but the problem is that I later want the new XxxFormatter() as instance variable of that object. Since the XxxFormatters share no common base class I cannot put them as a single field in the SerializingHelper class.

Do you have any Ideas?

public delegate void SerializingHandler(Stream s, object o);

class SerializingHelper
{
    public string Name { get; set; }
    public SerializingHandler Serializer { get; set; }
}

comboFormat.Items.AddRange(new object[] 
{ 
            new SerializingHelper{ Name = "Binary", 
Serializer = (s,o)=>new BinaryFormatter().Serialize(s,o),

            new SerializingHelper{ Name = "Soap", 
Serializer = (s,o)=>new SoapFormatter().Serialize(s,o), 

            new SerializingHelper{ Name = "Xml", 
Serializer = (s,o)=>new XmlSerializer(typeof(KontaktpartnerData), new Type[]   
 {typeof(ArrayList), typeof(KontaktPartner)}).Serialize(s,o), }

});

From stackoverflow

• If you just want to prevent instantiating a new serializer instance each time, you can instantiate them outside of the lambda:

  var binaryFormatter = new BinaryFormatter();
  
  comboFormat.Items.AddRange(new object[]
  { 
      new SerializingHelper
      {
          Name = "Binary",
          Serializer = binaryFormatter.Serialize
      }
  
      ...
  });
  

  ---

  If you really need to store the formatter as a field, you could do something like this:

  delegate void SerializingHandler<TFormatter>(TFormatter formatter,
                                               Stream stream,
                                               object graph);
  
  interface ISerializingHelper
  {
      void Serialize(Stream stream, object graph);
  }
  
  class SerializingHelper<TFormatter> : ISerializingHelper
  {
      private readonly SerializingHandler<TFormatter> handler;
      private readonly TFormatter formatter;
  
      public SerializingHelper(SerializingHandler<TFormatter> handler,
                               TFormatter formatter)
      {
          this.handler = handler;
          this.formatter = formatter;
      }
  
      public TFormatter Formatter
      {
          get { return this.formatter; }
      }
  
      public void Serialize(Stream stream, object graph)
      {
          this.handler(this.formatter, stream, graph);
      }
  }