CODEWITHSUNDEEP
c#json.net
Luke
Luke

Reputation: 59

Json deserialize generics

I'm trying to deserialize objects using generics but consumers can't pick them up even though they look completely fine.

    private readonly IContainer _container = Ioc.GetContainer();

    public async Task Test()
    {
        var command = new TestCommand();

        var serializeObject = JsonConvert.SerializeObject(command);

        var message = JsonConvert.DeserializeObject(serializeObject, command.GetType());

        await Process(message);

        await Process(command);
    }

    private async Task Process<TMessage>(TMessage message)
    {
        await _container.Resolve<IMessageDispatcher>().Dispatch(message);
    }

    public async Task Dispatch<TMessage>(TMessage message)
    {
        using (var scope = _lifetimeScope.BeginLifetimeScope())
        {
            var consumers = scope.Resolve<IEnumerable<IMessageConsumer<TMessage>>>().ToList();

            if(consumers.Any() == false) throw new Exception($"No consumer for message {message.GetType().Name}");

            foreach (var consumer in consumers)
            {
                await consumer.Consume(message, CancellationToken.None);
            }
        }
    }

    public interface IMessageConsumer<TMessage>
    {
      Task Consume(TMessage message, CancellationToken cancellationToken);
    }

My message fails to find a consumer but the command variable does? Even though these objects look identical?

Upvotes: 0

Views: 469

Answers (1)

mortb
mortb

Reputation: 9839

The variable message below will be of compile time type object and runtime type TMessage. For generics type binding to work, the type needs to be possible to evaluate at compile time. 

var message = JsonConvert.DeserializeObject(serializeObject, command.GetType());

You will either need to Deserialize to a more specific generic type: 

var message = JsonConvert.DeserializeObject<TestCommand>(serializeObject);

or check the type at runtime in some way, for example:

if(message is TestCommand)

...

Upvotes: 1

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