How to post dictionary values from Postman to a .net core 3.1 API

Question

I'm creating a simple Web API using .Net core 3.1 and I am having issues successfully posting a dictionary using Postman.

I have the following controller action:

[HttpPost("{id}/metas")]
[ProducesResponseType(typeof(Meta), 201)]
public async Task<IActionResult> CreateMeta([FromForm] NewMeta newMeta)
{
    return Ok();
}

The NewMeta currently looks like this:

public class NewMeta
{

    /// <summary>
    /// File descriptors
    /// </summary>
    public Dictionary<string, object> Refs { get; set; }

    /// <summary>
    /// Associated file
    /// </summary>
    public IFormFile File { get; set; }

}

I am trying to use Postman to POST dictionary data as well as a file.

I've tried using the various Key/Value settings within postman. An example shown in the images.

Results in :

How can i pass in a value? This API is early in its development so I can change anything that is needed.

Your dictionary is of type `string, object` but your passsing in `string, int` — Train, Dec 06 '19 at 20:34
I don't think you can use plain `object` for Web API Calls. Try something along these lines: https://stackoverflow.com/a/46868313/2720343 — Dortimer, Dec 06 '19 at 20:35
FML...Thanks folks. Figured I could use Object to keep it available for stirng/int/bool. Doesn't seem that is an easy option though. Changing to string works. — Darren Wainwright, Dec 06 '19 at 20:37
You could also send JSON from the body. It works with the objects too. — Hadi Samadzad, Dec 06 '19 at 20:42

score 1 · Answer 1 · edited Aug 22 '21 at 21:02

1

Use public Dictionary<string, string> Refs in view model in controller and map to Dictionary<string, object>.

edited Aug 22 '21 at 21:02

XouDo

945
10
19

answered Aug 21 '21 at 09:50

user16719529

11
1

score 0 · Answer 2 · answered Dec 06 '19 at 20:42

0

Your form-data as to be cast by the framework into a NewMeta object.

That mean the structure of your data has to be exactly the same than what your controller expected. So you need only 2 keys : Refs (as a json dictionary) and File.

answered Dec 06 '19 at 20:42

Ashijo

90
8

How to post dictionary values from Postman to a .net core 3.1 API

2 Answers2