System.Text.Json deserialize uint

Question

So it seems like the new Json library doesn't deserialize ( or even serialize for that matter) the UInt32 types. In an MVC application the following is sent in the payload of a POST:

{
   "Overrides":{
      
   },
   "Directions":{
      "data1" : "data2"
   },   
   "ModeId": "1782354543",
   "TestNumber" : 10
}

And the class it should be serialized to is like this:

public class Payload
    {
        public uint ModeId;
        public Dictionary<string, string> Directions{ get; set; } = new();
        public Dictionary<string, string> Overrides { get; set; } = new();
        public int TestNumber { get; set; }
    }

But when the request is received, ModeId is 0. I tried adding a custom converter based on the unit tests I found here Like so:

public class UIntConverter : JsonConverter<uint>
    {
        public override uint Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            if (reader.TokenType == JsonTokenType.String)
            {
                string stringValue = reader.GetString();
                if (uint.TryParse(stringValue, out uint x))
                {
                    return x;
                }
            }
            if (reader.TokenType == JsonTokenType.Number)
            {
                return reader.GetUInt32();
            }

            throw new JsonException();
        }

        public override void Write(Utf8JsonWriter writer, uint value, JsonSerializerOptions options)
        {
            writer.WriteNumberValue(value);
        }
    }

And registering it like this:

services.AddControllers()
                .AddJsonOptions(options =>
                {
                    options.JsonSerializerOptions.WriteIndented = false;
                    options.JsonSerializerOptions.IgnoreNullValues = true;
                    options.JsonSerializerOptions.PropertyNamingPolicy = null;
                    options.JsonSerializerOptions.Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping;
                    options.JsonSerializerOptions.Converters.Add(new JsonStringEnumConverter());
                    options.JsonSerializerOptions.Converters.Insert(options.JsonSerializerOptions.Converters.Count,new UIntConverter());

                });

I even failed to serialize my class into string using the same converter. It just ignores the uid property.

var payload = new Payload()
{
   Directions = new Directions
   {
     {"data1", "data2" }
   },
   ModeId = 1782354543,
   TestNumber = 10
}
//then try to serialize
var defaultJsonSerializerSettings = new JsonSerializerOptions()
        {
            IgnoreNullValues = true,
            WriteIndented = false,
            PropertyNamingPolicy = null,
            Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping,
            Converters = { new UIntConverter()}            
        };
Serializer.Serialize(payload, typeof(Payload), defaultJsonSerializerSettings); 

It serializes everything, except the uint property which is ignored altogether.

What do you suggest/advise for the serialization/deserialization of a uint property?

[UPDATE] : The issue was the fact that I was trying to serialize/deserialize a field as opposed to a property with public accessors as is pointed out in the answers. It just so happened that field was of type uint.

Answer 1

If you're on .NET 5, or if - as @Jimi pointed out - install <PackageReference Include="System.Text.Json" Version="5.0.2" />, you can then use IncludeFields and AllowReadingFromString options:

var serializeOptions = new JsonSerializerOptions
{
    IncludeFields = true,
    NumberHandling = JsonNumberHandling.AllowReadingFromString
};

var p = JsonSerializer.Deserialize<Payload>(json, serializeOptions);

Before .NET5 you'll need to change ModeId to be a property.

---

BTW. You could deal with string/int with no converter:

public string ModeId {get; set}
public uint ModeIdParsed => uint.Parse(ModeId);

If you need to keep ModeId name then you could

public class Payload
{
   [JsonPropertyName("ModeId")]
   public string modeId {get;set;}

   [JsonIgnore]
   public uint ModeId => uint.Parse(modeId);
}

Unfortunately in 3.1 you'll need to keep the string variant public (deserializing privates is available from v5).