Receiving json as string always null-CodePudding

With an endpoint like this:

        [HttpPost("[action]")]
        public async Task<ActionResult> Import([FromBody]string request)
        {
            var list = JsonConvert.DeserializeObject<List<RequestQuote>>(request);

            return NoContent();
        }

request always seems to be null. It worked for a little while earlier today but not sure what changed.

Here is the client side where I do the call.

  var json = JsonConvert.SerializeObject(payload);
  var data = new StringContent(json, Encoding.UTF8, "application/json");
  var response = client.PostAsJsonAsync($"{endpoint}/api/v1.0/BatchImport/Import", data);

Payload is a List

Even when using

Import([FromBody] List<RequestQuote> request)

I get the same issue.

CodePudding user response：

If your controller has the [ApiController] attribute, you can put the data type you want to parse as the parameter of the method. I believe what is happening is that your program is trying to parse the JSON to a string type, which isn't what you want. You can try the code below, which should achieve what you're looking for.

[HttpPost("[action]")]
public async Task<ActionResult> Import([FromBody]List<RequestQuote> list)
{
    // The parsed object should now be available here as "list"
    return NoContent();
}

Alternatively, this post suggests pulling the body of the request directly. Either solution should be valid.

CodePudding user response：

There is a bug in the code, the data is serialized twice, the second time when you use PostAsJsonAsync. Try this

var json = JsonConvert.SerializeObject(payload);

var data = new StringContent(json, Encoding.UTF8, "application/json");

var response = await client.PostAsync($"{endpoint}/api/v1.0/BatchImport/Import", data);

if (response.IsSuccessStatusCode)
    {
        var stringData = await response.Content.ReadAsStringAsync();
        var result = JsonConvert.DeserializeObject<ViewModel>(stringData);
    }

and action should be

public async Task<ActionResult> Import([FromBody] List<RequestQuote> request)