Correctly Override Newtonsoft.Json Method

Question

Background

I need to override the below method so it will deserialize an object's property without failing.

   JsonConvert.DeserializeObject()

It is failing because it is trying to convert a key pair value which contains either "Y" or "N" to a property which is of type Boolean.

This is the error

Could not convert string to boolean: Y.

I'm calling the method like this:

 private List<T> GetBindingSource<T>(List<T> list, string JsonKey, Dictionary<string, string> dictOriginalJSON)
    {
        var OutJson = "";
        if (dictOriginalJSON.TryGetValue(JsonKey, out OutJson))
        {
        list = JsonConvert.DeserializeObject<List<T>>(OutJson); //Call fails here 
        }

        return list;
    }

My Attempted Solution

After reading up on the issue it seems the best thing to do would be to override the method. I've chosen this solution by #entre

How to get newtonsoft to deserialize yes and no to boolean

using System;
using Newtonsoft.Json;

namespace JsonConverters
{
    public class BooleanJsonConverter : JsonConverter
    {
        public override bool CanConvert( Type objectType )
        {
            return objectType == typeof( bool );
        }

        public override object ReadJson( JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer )
        {
            switch ( reader.Value.ToString().ToLower().Trim() )
            {
                case "true":
                case "yes":
                case "y":
                case "1":
                    return true;
                case "false":
                case "no":
                case "n":
                case "0":
                    return false;
            }

            // If we reach here, we're pretty much going to throw an error so let's let Json.NET throw it's pretty-fied error message.
            return new JsonSerializer().Deserialize( reader, objectType );
        }

        public override void WriteJson( JsonWriter writer, object value, JsonSerializer serializer )
        {
        }

Problem

When I make the new call to the extended class like below.

list = BooleanJsonConverter.DeserializeObject<List<T>>(OutJson);

I get this error message.

QueueDetail.BooleanJsonConverter' does not contain a definition for 'DeserializeObject'

Question

What am I doing wrong? This is the first time I've attempted this, so I may well be missing something.

If BooleanJsonConverter inherits JsonConverter. Why doesn't BooleanJsonConverter contain the call i was using previously ?

you haven't told `JsonSerializer` to use your converter – Daniel A. White Jun 17 '16 at 16:34 — Daniel A. White, Jun 17 '16 at 16:34
What do you mean and how do you do that? – Dan Cundy Jun 17 '16 at 16:36 — Dan Cundy, Jun 17 '16 at 16:36
@DanCundy look to my answer – blogprogramisty.net Jun 17 '16 at 16:43 — blogprogramisty.net, Jun 17 '16 at 16:43

blogprogramisty.net · Accepted Answer · 2016-06-17T16:54:12.667

5

You haven't told JsonSerializer to use your converter.

See documentation of JSON.NET here:

http://www.newtonsoft.com/json/help/html/CustomJsonConverter.htm

then You can try call like this:

JsonConvert.DeserializeObject<<List<T>>(OutJson, new BooleanJsonConverter(typeof(<List<T>)));

You can also use Json atributte in Your T object.

 [JsonConverter(typeof(BooleanJsonConverter))]

edited Jun 17 '16 at 16:54

answered Jun 17 '16 at 16:37

blogprogramisty.net

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Correctly Override Newtonsoft.Json Method

Background

My Attempted Solution

Problem

Question

1 Answers1