Alternative of using built-in object that implements IDictionary for a web method

Question

I have a web application that uses the Web Service created in ASP.NET. In this, web service I want to pass an collection object of Key Value type (i.e. something like Hashtable or Dictionay).

But we cannot use objects that implements from IDictionary.

I do not want to create a serialized class in my web service.

Can anyone suggest me the best approach for this?

Answer 1

You could try to use 2 arrays, 1 for keys and one for values, where the indexes of the arrays match up. Not the most ideal solution but a valid one. The internals of the webservice you can use IDictionary and just pass out the Keys and Values of that object.

Answer 2

Maybe try using Pair class?

Answer 3

dev.e.loper is almost right. You can use a List<Pair>.

Alternatively, you can use List<KeyValuePair<TKey,TValue>>. See KeyValuePair.

Answer 4

I'm not totally clear on your question, but maybe you are needing something like this?

using System.Collections.Generic;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;

[XmlRoot("dictionary")]
public class SerializableDictionary<TKey, TValue> : Dictionary<TKey, TValue>, IXmlSerializable
{
    public XmlSchema GetSchema()
    {
        return null;
    }

    public void ReadXml(XmlReader reader)
    {
        var keySerializer = new XmlSerializer(typeof(TKey));
        var valueSerializer = new XmlSerializer(typeof(TValue));

        bool wasEmpty = reader.IsEmptyElement;
        reader.Read();

        if (wasEmpty)
        {
            return;
        }

        while (reader.NodeType != XmlNodeType.EndElement)
        {
            reader.ReadStartElement("item");

            reader.ReadStartElement("key");
            var key = (TKey)keySerializer.Deserialize(reader);
            reader.ReadEndElement();

            reader.ReadStartElement("value");
            var value = (TValue)valueSerializer.Deserialize(reader);
            reader.ReadEndElement();

            this.Add(key, value);
            reader.ReadEndElement();
            reader.MoveToContent();
        }

        reader.ReadEndElement();
    }

    public void WriteXml(XmlWriter writer)
    {
        var keySerializer = new XmlSerializer(typeof(TKey));
        var valueSerializer = new XmlSerializer(typeof(TValue));

        foreach (var key in this.Keys)
        {
            writer.WriteStartElement("item");
            writer.WriteStartElement("key");
            keySerializer.Serialize(writer, key);
            writer.WriteEndElement();
            writer.WriteStartElement("value");
            TValue value = this[key];
            valueSerializer.Serialize(writer, value);
            writer.WriteEndElement();
            writer.WriteEndElement();
        }
    }
}

Answer 5

You can inherit from KeyedCollection which is Serializable.

http://msdn.microsoft.com/en-us/library/ms132438.aspx