Question

A dictionary where value is an anonymous type in C#

Is it possible in C# to create a System.Collections.Generic.Dictionary<TKey, TValue> where TKey is unconditioned class and TValue - an anonymous class with a number of properties, for example - database column name and it's localized name.

Something like this:

new { ID = 1, Name = new { Column = "Dollar", Localized = "Доллар" } }
 45  45433  45
1 Jan 1970

Solution

 48

You can't declare such a dictionary type directly (there are kludges but these are for entertainment and novelty purposes only), but if your data is coming from an IEnumerable or IQueryable source, you can get one using the LINQ ToDictionary() operator and projecting out the required key and (anonymously typed) value from the sequence elements:

var intToAnon = sourceSequence.ToDictionary(
    e => e.Id,
    e => new { e.Column, e.Localized });
2009-10-24

Solution

 21

As itowlson said, you can't declare such a beast, but you can indeed create one:

static IDictionary<TKey, TValue> NewDictionary<TKey, TValue>(TKey key, TValue value)
{
    return new Dictionary<TKey, TValue>();
}

static void Main(string[] args)
{
    var dict = NewDictionary(new {ID = 1}, new { Column = "Dollar", Localized = "Доллар" });
}

It's not clear why you'd actually want to use code like this.

2009-10-25