ConfigurationElementCollection with primitive types

Question

I'm working with the System.Configuration namespace types to store configuration for my application. I need to store a collection of primitive types (System.Double) as part of that configuration. It seems like overkill to create the following:

[ConfigurationCollection(typeof(double), AddItemName="TemperaturePoint", 
    CollectionType=ConfigurationElementCollectionType.BasicMap)]
class DoubleCollection : ConfigurationElementCollection
{
    protected override ConfigurationElement CreateNewElement()
    {
        return // Do I need to create a custom ConfigurationElement that wraps a double?
    }

    protected override object GetElementKey(ConfigurationElement element)
    {
        return // Also not sure what to do here
    }
}

I can't imagine I'm the first person to encounter this problem. Any ideas?

Answer 1

I was able to get this to work without much customization. It is similar to JerKimball's answer but I avoids processing the custom string processing by using a TypeConverter attribute for the ConfigurationProperty.

My custom config section implementation:

using System.Configuration;
using System.ComponentModel;

class DomainConfig : ConfigurationSection
{     

    [ConfigurationProperty("DoubleArray")]
    [TypeConverter(typeof(CommaDelimitedStringCollectionConverter))]
    public CommaDelimitedStringCollection DoubleArray
    {
        get { return (CommaDelimitedStringCollection)base["DoubleArray"]; }
    }
}

How it's used:

var doubleValues = from string item in configSection.DoubleArray select double.Parse(item);

And the config file:

<DomainConfig DoubleArray="1.0,2.0,3.0"></DomainConfig>