Posting from jQuery.ajax to a ASP.Net 5 Api Controller does not post integer parameter-CodePudding

I have the following api controller:

[Route("api/[controller]")]
[ApiController]
public class WeightingDefinitionsApiController : ControllerBase
{
    [HttpPost]
    public async Task<ActionResult<WeightingDefinition>> PostWeightingDefinition(int id)
    {...
    }
}

When I call the PostWeightingDefinition from the .Net code it works. Now I want to call this code from a .cshtml file using a jquery.ajaxcall:

var apiurl = "/api/WeightingDefinitionsApi/";
var data = { id: 13 };
$.ajax({
    url: apiurl,
    type: 'POST',
    dataType: 'json',
    data:data,
    success: function (d) {
                 alert("Saved Successfully");
                },
    error: function (x,y,z) {
                 alert("Error please try again");
                }
            });

If I connect this code to a button.click() event the code in the api controller is called but the id parameter is zero instead of 13.

Where am I going wrong?

CodePudding user response：

You ajax request sends the id as form data payload. This happens because you didn't specify the contentType option for the jQuery.ajax() request and the default is application/x-www-form-urlencoded; charset=UTF-8. So you have to add [FromForm] attribute to the id parameter of your action:

[HttpPost]
public async Task<ActionResult<WeightingDefinition>>
    PostWeightingDefinition([FromForm]int id)
{
    ...
}

When you don't specify any attribute to the id parameter then [FromQuery] is inferred so you would have to pass the id as query parameter:

var apiurl = "/api/WeightingDefinitionsApi?id=13";

Check the following links:

ApiController attribute - Binding source parameter inference documentation

jQuery.ajax() documentation