Asp.net Core Post parameter is always null [closed]

Question

Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers.

This question was caused by a typo or a problem that can no longer be reproduced. While similar questions may be on-topic here, this one was resolved in a way less likely to help future readers.

Closed 5 years ago.

Improve this question

I'm sending POST from fiddler:

POST http://localhost:55924/api/Product HTTP/1.1
User-Agent: Fiddler
Host: localhost:55924
Content-Type: application/json; charset=utf-8
Content-Length: 84

{"Ean″:”1122u88991″,”Name″:”Post test″,"Description":"Post test desc"}

But Post method always gets null.

// POST api/Product
[HttpPost]
public IActionResult PostProduct([FromBody]Product product)
{
    if (!ModelState.IsValid)
    {
        return BadRequest(ModelState);
    }

    _repo.Add(product);

    return CreatedAtRoute("GetToode",product);
}

When I use [FormBody] product is always null, when not using it product is valued but with all fields being null. Product class is simple.

public class Product
{
    public int ProductID { get; set; }
    public string EAN { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }
    public int? CategoryID { get; set; }
}

i tried adding NullValueHandling to ConfigureServices as proposed in post but no use.

services.AddMvc()
    .AddJsonOptions(jsonOptions =>
    {
        jsonOptions.SerializerSettings.NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore;
    });

try it sending all properties. Include ProductID and CategoryID. — Fabricio Koch
– Fabricio Koch, Commented Sep 28, 2016 at 12:59
This is like you mapping field is not matching, name should be same as in product class, also try with removing [FromBody] — Bharat
– Bharat, Commented Sep 28, 2016 at 12:59

Ignas · Accepted Answer · 2016-09-28 13:51:32Z

7

I just had to correct the double quotes in your POST request and it worked. Try this:

{"Ean":"1122u88991","Name":"Post test","Description":"Post test desc"}

See screenshot below.

answered Sep 28, 2016 at 13:51

Ignas

4,38821 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

martinv Over a year ago

Honestly I feel so so dumb right now, that I didn't noticed it myself.

jcespinoza Over a year ago

It is not clear what quotes this answer refers to because the question was since edited a few times. FYI, OP used a mix of ″ ” and " characters in the original request body.

jcespinoza · Accepted Answer · 2019-03-19 20:56:31Z

6

I experience a similar problem but I had no check for the validity of the ModelState as the OP. When this happens, inspecting it in debug mode will likely point you to what's wrong with the model:

In this example I was using an invalid string 'A' as test value for a Guid property, so the model was always null.

answered Mar 19, 2019 at 20:56

jcespinoza

3235 silver badges12 bronze badges

1 Comment

Gimmly Over a year ago

Thank you for the great answer! I was shooting in the dark before stumbling upon this

Alexander Kozachenko · Accepted Answer · 2018-07-18 09:25:02Z

1

Had the same problem. It turned out that I had no public parameterless constructor for class of incoming instance. In this case, Product had only protected constructors and parameter was always null no matter what. Hope it helps somebody.

answered Jul 18, 2018 at 9:25

Alexander Kozachenko

9553 gold badges16 silver badges29 bronze badges

Collectives™ on Stack Overflow

Asp.net Core Post parameter is always null [closed]

3 Answers 3

2 Comments

1 Comment

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

1 Comment

Comments

Linked

Related