.net core asp.net webapi 2 post参数值始终为null（字符串）或0（int）

已经通过几十个链接，都说相同的解决方案。 为api调用中的参数创建一个对象。并使用json传递完全相同的对象

因此，API调用如下（即命中）：

输入对象的定义如下：

public class SearchParams
  {
    public string searchWord { get; set; }

    public int anid { get; set; }
  }

因此，呼吁：

let item = {
          searchWord: searchKeyword.value.trim(),
          anid: 1
      };

      const uri = "../../WebApi/SearchItems";

      fetch(uri, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'Accept': 'application/json'
        },
        body: JSON.stringify(item),
        //credentials: 'include',
        mode: 'cors',
      })

看看网络流量，通过的报头是：

:authority: localhost:44386
:method: POST
:path: /WebApi/SearchItems
:scheme: https
accept: application/json
accept-encoding: gzip, deflate, br
accept-language: en-GB,en-US;q=0.9,en;q=0.8
content-length: 32
content-type: application/json
cookie: .AspNetCore.Session=CfDJ8LGmdU3gpbZIvSkveH0x8cMT8VibUQlc07yQ8SJOo6DJkNqykRsAz2V6NVuQ5zQhzBNiHjZ2iRJc%2Fno44sQdQJhsVPnktzx8EWu%2Bptg9ONjmErDP3TZ1csme%2FAJ3H5hSgvooxH0snE00och2ov4ZldFCosHYGH6X70ESjL8PbcJg; .AspNetCore.Antiforgery.Q2hy0CiNRlg=CfDJ8LGmdU3gpbZIvSkveH0x8cOOBFRZOyah2508xPXIUjTbV_weFLdM06pME-M-kc2l48FOmSym_5JS9GUHJeciQEKJI9SHBu1D-5wLcVF4de3rYsjKRsI67qGrCado7eBFDBAbeYFOLWEMbXXCQr_0vlA
origin: https://localhost:44386
referer: https://localhost:44386/lb_users/Details/11
sec-fetch-dest: empty
sec-fetch-mode: cors
sec-fetch-site: same-origin
user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36

因此，有效载荷为：

{"searchWord":"qwerty","anid":1}

我的VS调试器和邮递员都返回null/0值

对.NETCore来说相对较新。 那么，我在这里遗漏了什么基本的东西，因为我看到的几十个问题似乎都与我在解决方案中添加的问题相同

提前谢谢

编辑： 这很有效

const uri = "../../WebApi/SearchItems";
      fetch(uri, {
        method: 'POST',
        headers: {
          "Content-type": "application/x-www-form-urlencoded; charset=UTF-8"
        },
        body: "searchWord=" + searchKeyword.value.trim() + "&anid=1",
        //credentials: 'include',
        mode: 'cors',
      })

因此，JSON似乎是个问题。

---

JSON对象是否已从传递给api调用的过程中删除？

我测试了asp.net webapi2和asp.net core，两者都可以工作。 以下是asp.net webapi2的演示：

ApiController：

public class ValuesController : ApiController
    {
        [System.Web.Http.HttpPost]
        public string GetVal(SearchParams searchParams)
        {
            return "success";
        }
    }
    public class SearchParams
    {
        public string searchWord { get; set; }

        public int anid { get; set; }
    }

阿贾克斯：

薪资水平：

{searchWord: "hghgfgf", anid: 1}

结果: 您还可以尝试创建一个新项目，并对其进行测试

<input id="searchWord"/>
<button onclick="sendData()">ssss</button>
<script>
    function sendData() {
        let item = {
            searchWord: $("#searchWord").val().trim(),
            anid: 1
        };

        const uri = "../api/Values";

        fetch(uri, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Accept': 'application/json'
            },
            body: JSON.stringify(item),
            //credentials: 'include',
            mode: 'cors',
        })
    }
</script>

:authority: localhost:44383
:method: POST
:path: /api/Values
:scheme: https
accept: application/json
accept-encoding: gzip, deflate, br
accept-language: en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7
content-length: 33
content-type: application/json
cookie: .AspNetCore.Culture=c%3Den-US%7Cuic%3Den-US; .AspNetCore.Antiforgery.I5tvYLHG_pU=CfDJ8AkZmG9N6OhEnYVb3Xy31rQgFnXqHPkWTaV4nUodZGM9SfyhvD5jztl-kzo768oHkGPUYV-bOoSNBP5OuTHO_yd08w-IxrsO39HceHJgOIqC5ePYLIxXd0w9cBzYeWEu5amihQhOqiLySw376bp9YdM
origin: https://localhost:44383
referer: https://localhost:44383/Home/Index1
sec-fetch-dest: empty
sec-fetch-mode: cors
sec-fetch-site: same-origin
user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36

{searchWord: "hghgfgf", anid: 1}