如何向 C# 中的 ASP.NET Core MVC controller 发送数据？

Question

I am trying to send data from my Javascript to my post method controller. I have knockout as my method to bind from Javascript to my view.

This is my controller, and this is wher convocationData is null

public async Task<ActionResult> CreateConvocation(string convocationData)
{
    string baseUrl = "http://localhost:8080";
    HttpClient client = new HttpClient();
    client.BaseAddress = new Uri(baseUrl);

This is how I try to call the method using jQuery:

var tmpSession = self.addSession();
var tmpDescription = self.addDesc();
var convocationData = {
            sessionCode: tmpSession,
            description: tmpDescription
        };

$.ajax({
            url: '/Convocations/CreateConvocation',
            type: 'POST',
            dataType: 'json',
            data: JSON.stringify(convocationData),
            contentType: 'application/json',
            success: function (data) {
                self.Convocations.push(new Convocation(self.addSession(), self.addDesc()));
                self.addDesc("");
                self.addSession("");
            },
            error: function (err) {
                alert(err.status + " : " + err.statusText);
            }
        });

Answer 1

Add [FromBody] attribute like this

[HttpPost]
public async Task<ActionResult> CreateConvocation([FromBody]string convocationData)
{
    return text;
}

You can read more here Accepting Raw Request Body Content with ASP.NET Web API

Update:

Also, read zgood's comments to your post. Instead of using JSON.stringify you should create a corresponding model as he is describing in his comment.

Update 2:

JS model class

class Convocation {
  constructor(sessionCode, description) {
    this.sessionCode = sessionCode;
    this.description = description;
  }
}

C# DTO class

public class Convocation
{
    public string SessionCode{ get; set; }
    public string Description { get; set; }
}

Then you can update your action method to this

[HttpPost]
public async Task<ActionResult> CreateConvocation([FromBody]Convocation convocation)
{
    return text;
}

and ajax post to this:

$.ajax({
    url: '/Convocations/CreateConvocation',
    type: 'POST',
    dataType: 'json',
    data: new Convocation(tmpSession, tmpDescription),
    contentType: 'application/json',
    success: function(data) {
        self.Convocations.push(new Convocation(self.addSession(), self.addDesc()));
        self.addDesc("");
        self.addSession("");
    },
    error: function(err) {
        alert(err.status + " : " + err.statusText);
    }
});

I didn't test the code but it should work.