How to parse JSON using RestSharp?

Question

var client = new RestClient("http://10.0.2.2:50670/api");

var request = new RestRequest("Inventory", Method.GET);

request.OnBeforeDeserialization = resp => { resp.ContentType = "application/json"; };

// execute the request to return a list of InventoryItem
RestResponse<JavaList<InventoryItem>> response = (RestResponse<JavaList<InventoryItem>>)client.Execute<JavaList<InventoryItem>>(request);

The content returned is a JSON string, an array of objects. The following is a short excerpt of it:

[{"Id":1,"Upc":"1234567890","Quantity":100,"Created":"2012-01-01T00:00:00","Category":"Tequila","TransactionType":"Audit","MetaData":"PATRON 750ML"},{"Id":2,"Upc":"2345678901","Quantity":110,"Created":"2012-01-01T00:00:00","Category":"Whiskey","TransactionType":"Audit","MetaData":"JACK DANIELS 750ML"},{"Id":3,"Upc":"3456789012","Quantity":150,"Created":"2012-01-01T00:00:00","Category":"Vodka","TransactionType":"Audit","MetaData":"ABSOLUT 750ml"}]

The error message:

Operation is not valid due to the current state of the object

What is wrong here? My InventoryItem has the same properties as each object in the JSON string. Am I missing a step?

Answer 1

I suspect that SimpleJson, used in RestSharp can't deserialise to a JavaList.

First I would try deserialising to a:

List<InventoryItem>

Failing that, I recommend ServiceStack.Text - .Net's fastest JSON library; and do:

var response = client.Execute(request);
var thingYouWant = JsonSerializer.DeserializeFromString<List<InventoryItem>>(response.Content);

This is actually what I do myself.

Edit (Thank you to commentators): In newer versions this would now be:

var deserializer = new JsonDeserializer();
deserializer.Deserialize<List<InventoryItem>>(response);