Bson array (de)serialization with Json.NET

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.

Hmmm, from where I sit, your code should work, but Json.Net seems to think that your serialized array of strings is a dictionary. This could be because, according to the BSON specification, arrays actually do get serialized as a list of key-value pairs just like objects do. The keys in this case are simply the string representations of the array index values.

In any case, I was able to work around the issue in a couple of different ways:

1. Deserialize to a Dictionary and then manually convert it back to an array.

   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);
       bytes = ms.ToArray();
   }
   
   // Deserialization
   using (var ms = new MemoryStream(bytes))
   using (var bson = new BsonReader(ms))
   {
       var dict = jsonSerializer.Deserialize<Dictionary<string, string>>(bson);
       array = dict.OrderBy(kvp => kvp.Key).Select(kvp => kvp.Value).ToArray();
   }
   

2. Wrap the array in an outer object.

   class Wrapper
   {
       public string[] Array { get; set; }
   }
   

   Then serialize and deserialize using the wrapper object.

   var jsonSerializer = new JsonSerializer();
   var obj = new Wrapper { Array = new string[] { "A", "B" } };
   
   // Serialization
   byte[] bytes;
   using (var ms = new MemoryStream())
   using (var bson = new BsonWriter(ms))
   {
       jsonSerializer.Serialize(bson, obj);
       bytes = ms.ToArray();
   }
   
   // Deserialization
   using (var ms = new MemoryStream(bytes))
   using (var bson = new BsonReader(ms))
   {
       obj = jsonSerializer.Deserialize<Wrapper>(bson);
   }
   

Hope this helps.