.net6 接收json数据 Controller http post

要添加这两个包

前端ajax请求

 function tst() {
        $.ajax({
            type: "POST",
            contentType: "application/json",
            url: "/HelloWorld/Welcome",
            data: JSON.stringify({ "ID":1,"name": "haha" }),
            dataType: "json",
            success: function (data) {
                alert(data);
            }
        });
    };

关键在contentType 和JSON.stringify 如果这2两个没加上后台还是接收不到的！
contentType: “application/json”,
后台接收加上一个 [FromBody]

后台示例

  public class test
 {
            public int ID { get; set; }
            public string name { get; set; }
  }
  public string Welcome([FromBody]test ha)
  {}

后台完整代码

using DotNetWebApp0514a.Models;
using Microsoft.AspNetCore.Mvc;
using Newtonsoft.Json;
using System.Collections.Generic;
using System.Diagnostics;
using System.Net;
using System.IO;
using System.Web;

namespace DotNetWebApp0514a.Controllers
{
    public class UserData
    {
        public string id { get; set; }
        public string name { get; set; }
    }

    public class HomeController : Controller
    {
        private readonly ILogger<HomeController> _logger;

        public String getQrCode(Object data)
        {
            mylog("jsonData" + data);
            String ticket = "";
            return ticket;
        }

        public void mylog(String str, String str1="")
        {
            System.Diagnostics.Debug.WriteLine(str, str1);
        }

        public HomeController(ILogger<HomeController> logger)
        {
            _logger = logger;
        }
        public IActionResult Index()
        {
            mylog("进入 Index");
            return View();
        }
        public IActionResult Privacy()
        {
            mylog("进入 Privacy");
            return View();
        }
        // 能自动装配form表单数据 theJson(StuData stu)
        // 但不能自动装配json，要这样 theJson([FromBody]UserData stu)
        public List<UserData> theJson([FromBody]UserData stu)
        {
            String str = JsonConvert.SerializeObject(stu);
            System.Diagnostics.Debug.WriteLine("收到："+str);


            // Request.QueryString["ssss"].ToString();

            List<UserData> dataList = new List<UserData>() {
                new UserData {id="1",name="asd" },
            };
            String theJson = JsonConvert.SerializeObject(dataList);
            System.Diagnostics.Debug.WriteLine("theJson:" + theJson);

            return dataList;

            // 原文链接：https://blog.csdn.net/wesleysd/article/details/123065099
        }

        [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error()
        {
            System.Diagnostics.Debug.Write("进入 Error");
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }
    }
}