Bson array (de)serialization with Json.NET

Question

I am simply trying to serialize and deserialize a string array in Bson format using Json.NET, but the following code fails:

var jsonSerializer = new JsonSerializer();
var array = new string [] { "A", "B" };

// Serialization
byte[] bytes;
using (var ms = new MemoryStream())
using (var bson = new BsonWriter(ms))
{
    jsonSerializer.Serialize(bson, array, typeof(string[]));
    bytes = ms.ToArray();
}

// Deserialization
using (var ms = new MemoryStream(bytes))
using (var bson = new BsonReader(ms))
{
    // Exception here
    array = jsonSerializer.Deserialize<string[]>(bson);
}

Exception message:

Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.String[]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.

To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.

How can I get this to work?

Answer 1

Set ReadRootValueAsArray to true on BsonReader

http://james.newtonking.com/projects/json/help/index.html?topic=html/P_Newtonsoft_Json_Bson_BsonReader_ReadRootValueAsArray.htm

This setting is required because the BSON data spec doesn't save metadata about whether the root value is an object or an array.