The difference between [FromBody] and [FromForm] in .net core

1. Pay attention to the post-type api in .net core (the premise is that the [ApiController] feature is added to the Controller). The default is this.

1. If the client Content-Type is application/json, if the api interface uses a single object as a parameter, the parameter can be parsed normally with or without adding [FromBody], but if the object list is used as a parameter, it must be added [FromBody], otherwise [FromBody] must be added, otherwise the parameters cannot be read.

2. If the client's Content-Type is not application/json, the api interface must add [FromForm], otherwise the client will report a 400 error when calling the interface.

3. If [FromBody] is added and the Content-Type of the client is not application/json, the interface will report a 400 error.

How does asp.net core webapi receive Josn and convert it into an entity

Now you can treat JSON as a parameter such as data = "JSON" and serialize it after receiving it. Is there an asynchronous method for receiving automatic conversion before :

code show as below:

/// <summary>
        /// 站点信息
        /// </summary>
        /// <param name="SStation">站点编码</param>
        /// <param name="Type">站点类型：地表水：Dbs  引用水：yys   空气:Air  自动站：waterzd  酸雨：rain</param>
        /// <returns></returns>
        [HttpGet, HttpPost]
        [AllowAnonymous]
        public ActionResult SStationInfo([FromForm] string SStation, [FromForm] string Type)
        {
            string message = string.Empty;
            if (string.IsNullOrEmpty(SStation)) {
                message = $"缺少[SStation]参数！";
                return Ok(new { code = 201, message });
            }
            if (string.IsNullOrEmpty(Type))
            {
                message = $"缺少[Type]参数！";
                return Ok(new { code = 201, message });
            }
            StnDetail stnDetail = new StnDetail();
            stnDetail.imgs = this.Dao.FindAll<SStationImg>().Where(p => p.SStation == SStation).ToList();
            switch (Type)
            {
                case "Air":
                    stnDetail.air= this.Dao.FindAll<Air_SStation>().Where(p => p.SStation==SStation).FirstOrDefault();

                    break;
                case "Dbs":
                    stnDetail.dbs = this.Dao.FindAll<Dbs_SStation>().Where(p => p.SStation == SStation).FirstOrDefault();

                    break;
                case "yys":
                    stnDetail.dws = this.Dao.FindAll<DrinkingWater_SStation>().Where(p => p.SStation == SStation).FirstOrDefault();

                    break;
               case "rain":
                    stnDetail.rs = this.Dao.FindAll<Rain_SStation>().Where(p => p.SStationCode == SStation).FirstOrDefault();

                    break;
               case "waterzd":
                    stnDetail.ws = this.Dao.FindAll<WaterZd_SStation>().Where(p => p.SStation == SStation).FirstOrDefault();

                    break;
                default:
                    message = $"[Type]参数错误！";
                    break;
            }

            return Ok(new { code = 200, message, stnDetail });
        }

Based on the above, if the client submits json data, it is recommended to add [FromBody].

If the Content-Type of the data submitted by the client is not application/json, an error will be reported. To solve the error, you need to add [FromForm] to the interface.