the values field is required

February 6, 2023

Detail: I am trying to set up a simple get/post method inside asp.net controller and using postman to set if its set up correctly. I have looked for similar question on stackoverflow and they did not fixed my issue

Error: My Get method works fine but my post method giving an following error. Please see below postman:

debug: if I add a break line inside post method. it is never reaching to that break line

Code in asp.net

[ApiController]
[Route("[controller]")]
public class CoursesTakenController : Controller
{
    [HttpGet]
    public IEnumerable<string> Get()
    {
       return new string[] {"value", "value" }
    }

    [HttpPost]
    public Task<ActionResult<string>> Post([FromBody] string values)
    {
        return Ok(values);
    }
}

I also tried this: but doesnt work

    [HttpPost]
    public async Task<IActionResult> Post([FromBody] string values)
    {
        return Ok();
    }

>Solution :

You are posting a json object while the method expects a string. System.Text.Json (default json serializer used by ASP.NET Core) is pretty restrictive in JsonTokenType handling, so either post a string i.e. just "RandomText" (or encoded into string json object – {\"values\":\"asdasdasd\"}) or change action to accept an object:

public class Tmp
{
    public required string Values { get; set; }
}

[HttpPost]
public async Task<ActionResult<string>> Post([FromBody] Tmp values)
{
   ...
}