Passing A List Of Objects Into An MVC Controller Method Using jQuery Ajax

Using NickW's suggestion, I was able to get this working using things = JSON.stringify({ 'things': things }); Here is the complete code.

$(document).ready(function () {
    var things = [
        { id: 1, color: 'yellow' },
        { id: 2, color: 'blue' },
        { id: 3, color: 'red' }
    ];      

    things = JSON.stringify({ 'things': things });

    $.ajax({
        contentType: 'application/json; charset=utf-8',
        dataType: 'json',
        type: 'POST',
        url: '/Home/PassThings',
        data: things,
        success: function () {          
            $('#result').html('"PassThings()" successfully called.');
        },
        failure: function (response) {          
            $('#result').html(response);
        }
    }); 
});


public void PassThings(List<Thing> things)
{
    var t = things;
}

public class Thing
{
    public int Id { get; set; }
    public string Color { get; set; }
}

There are two things I learned from this:

1. The contentType and dataType settings are absolutely necessary in the ajax() function. It won't work if they are missing. I found this out after much trial and error.

2. To pass in an array of objects to an MVC controller method, simply use the JSON.stringify({ 'things': things }) format.

I hope this helps someone else!

Couldn't you just do this?

var things = [
    { id: 1, color: 'yellow' },
    { id: 2, color: 'blue' },
    { id: 3, color: 'red' }
];
$.post('@Url.Action("PassThings")', { things: things },
   function () {
        $('#result').html('"PassThings()" successfully called.');
   });

...and mark your action with

[HttpPost]
public void PassThings(IEnumerable<Thing> things)
{
    // do stuff with things here...
}

I am using a .Net Core 2.1 Web Application and could not get a single answer here to work. I either got a blank parameter (if the method was called at all) or a 500 server error. I started playing with every possible combination of answers and finally got a working result.

In my case the solution was as follows:

Script - stringify the original array (without using a named property)

    $.ajax({
        type: 'POST',
        contentType: 'application/json; charset=utf-8',
        url: mycontrolleraction,
        data: JSON.stringify(things)
    });

And in the controller method, use [FromBody]

    [HttpPost]
    public IActionResult NewBranch([FromBody]IEnumerable<Thing> things)
    {
        return Ok();
    }

Failures include:

• Naming the content

  data: { content: nodes }, // Server error 500

• Not having the contentType = Server error 500

Notes

• dataType is not needed, despite what some answers say, as that is used for the response decoding (so not relevant to the request examples here).
• List<Thing> also works in the controller method