JsonConvert.Deserializer indexing issues

Question

While playing around Stack collection in C# I encountered the following issue. Exactly I am not sure why it is happening. Please put some light on the reason and alternative

Answer 1

Since this is a known behavior of Json.NET, as noted by this answer, a custom JsonConverter can be used when deserializing a stack that pushes items on in the correct order.

The following universal converter can be used with Stack for any T:

/// 

/// Converter for any Stack that prevents Json.NET from reversing its order when deserializing.
/// 
public class StackConverter : JsonConverter
{
    // Prevent Json.NET from reversing the order of a Stack when deserializing.
    // https://github.com/JamesNK/Newtonsoft.Json/issues/971
    static Type StackParameterType(Type objectType)
    {
        while (objectType != null)
        {
            if (objectType.IsGenericType)
            {
                var genericType = objectType.GetGenericTypeDefinition();
                if (genericType == typeof(Stack<>))
                    return objectType.GetGenericArguments()[0];
            }
            objectType = objectType.BaseType;
        }
        return null;
    }

    public override bool CanConvert(Type objectType)
    {
        return StackParameterType(objectType) != null;
    }

    object ReadJsonGeneric(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        if (reader.TokenType == JsonToken.Null)
            return null;
        var list = serializer.Deserialize>(reader);
        var stack = existingValue as Stack ?? (Stack)serializer.ContractResolver.ResolveContract(objectType).DefaultCreator();
        for (int i = list.Count - 1; i >= 0; i--)
            stack.Push(list[i]);
        return stack;
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        if (reader.TokenType == JsonToken.Null)
            return null;
        try
        {
            var parameterType = StackParameterType(objectType);
            var method = GetType().GetMethod("ReadJsonGeneric", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Public);
            var genericMethod = method.MakeGenericMethod(new[] { parameterType });
            return genericMethod.Invoke(this, new object[] { reader, objectType, existingValue, serializer });
        }
        catch (TargetInvocationException ex)
        {
            // Wrap the TargetInvocationException in a JsonSerializerException
            throw new JsonSerializationException("Failed to deserialize " + objectType, ex);
        }
    }

    public override bool CanWrite { get { return false; } }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }
}

Then add it to JsonSerializerSettings to correct the ordering of stacks when deserializing:

var settings = new JsonSerializerSettings { Converters = new[] { new StackConverter() } };
var jsonString = JsonConvert.SerializeObject(progress, settings);
var temp = JsonConvert.DeserializeObject(jsonString, settings);

Or mark the Stack property directly with [JsonConverter(typeof(StackConverter))]:

class Progress
{
    [JsonConverter(typeof(StackConverter))]
    public Stack Items { get; set; }

    public Progress()
    {
        Items = new Stack();
    }
}