C# Serialize Dictionary<ulong,ulong> to JSON

10
votes

I am trying to serialize a Dictionary to JSON, and get the following exception:

new JavaScriptSerializer().Serialize(mydict)`

Type 'System.Collections.Generic.Dictionary`2[[System.UInt64, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.Nullable`1[[System.UInt64, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]' is not supported for serialization/deserialization of a dictionary, keys must be strings or objects.

Is there an easy way to do this? Maybe converting the ulongs to strings via LINQ or something relatively terse?

3
c#jsonserializationdictionary
This is such an awful error message, isn't a value object still an object? - JoshBerke
possible duplicate of How do I convert a dictionary to a JSON String in C#? - Jim G.
I clearly posted the question first. Why isn't the other one marked as a duplicate? - Mark Richman

3 Answers

18
votes
var dict = mapping.ToDictionary(item => item.Key.ToString(), item => item.Value.ToString());`

that will convert any Dictionary<K,V> to Dictionary<string,string> and serialization then works.

3
votes

use NewtonSoft.Json instead of JavaScriptSerializer to overcome this problem:

Ex: 

JsonConvert.SerializeObject(mydict);
1
votes

The blog http://dukelupus.wordpress.com/2011/05/04/asp-net-mvc-json-and-a-generic-dictionary/ describes an extension method Dictionary ToJsonDictionary(this Dictionary input)