PutAsync不会将请求发送到Web api，但是提琴手可以正常工作

本文介绍了PutAsync不会将请求发送到Web api，但是提琴手可以正常工作的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

几个小时以来，我一直在试图找出问题所在，而我只是找不到问题所在.

I have been trying to figure out what is going wrong for a few hours now and i just can't find what is going wrong.

通过Mvc应用程序，put方法不会被命中，请求不会发生.但是，当我在提琴手中对其进行测试时，api中的PutMethod可以正常工作.

Via the Mvc application the put method doesn't get hit, the request doesn't happen. But when i test it in fiddler the PutMethod in the api works.

希望有人可以帮我清理一下.

Hopefully someone can clear things up for me.

也欢迎使用指针以提供更好的结构或一些好的文档.

Also pointers for a better structure or some good documentation are welcome .

public void UpdateWerknemerCompetentieDetail(int wnID, int WNC, CompetentieWerknemerDetail detail) { using (HttpClient client = new HttpClient()) { string token = (string)HttpContext.Current.Session["token"]; client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token); var wn = GetWerknemerById(wnID); //var wnc = wn.CompetentiesWerknemer.Select(c => c).Where(c => c.ID == WNC).FirstOrDefault(); detail.CompetentieWerknemerID = WNC; //wnc.CompetentieWerknemerDetail = detail; var url = String.Format(URL + "PutDetails?id=" + WNC); var json = JsonConvert.SerializeObject(detail, new JsonSerializerSettings() { ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore }); var response = client.PutAsync(url, new StringContent(json, Encoding.UTF8, "application/json")); } }

上面的代码是我的服务，应该向api发出请求.

The above code is my service that should make the request to the api.

这是Web api IHttpActionResult方法(put方法).

Here is the web api IHttpActionResult method (the put method).

[Route("PutDetails")] [HttpPut] public IHttpActionResult PutWerknemerCompetentieDetails(int id, [FromBody]CompetentieWerknemerDetail cwn) { if (!ModelState.IsValid) { return BadRequest(ModelState); } if (id != cwn.CompetentieWerknemerID) { return BadRequest(); } //_db.Entry(cwn).State = EntityState.Modified; try { _db.CompetentieWerknemerDetail.Add(cwn); _db.SaveChanges(); } catch (DbUpdateConcurrencyException) { if (!WerknemerExist(id)) { return NotFound(); } else { throw; } } return StatusCode(HttpStatusCode.NoContent); }

推荐答案

HttpClient.PutAsync 是异步API，它返回表示操作的 Task< HttpResponseMessage> 它将在将来完成，您需要 await .您将 HttpClient 包裹在 using 语句中，这意味着在触发异步PUT之后，您将处置客户端，该客户端在请求中导致竞争状态和对象的处置，这可能是您没有看到请求触发的原因.

HttpClient.PutAsync is an asynchronous API, it returns a Task<HttpResponseMessage> which represents an operation which will complete in the future, which you need to await. You're wrapping your HttpClient inside a using statement, which means that right after you trigger the asynchronous PUT, you're disposing the client which causes a race condition with the request and the disposal of your object, and is probably the reason you're not seeing the request fire.

您有两种选择.可以在其中使用方法 async Task 和 await :

You have two choices. Either make the method async Task and await inside it:

public async Task UpdateWerknemerCompetentieDetailAsync( int wnID, int WNC, CompetentieWerknemerDetail detail) { using (HttpClient client = new HttpClient()) { string token = (string)HttpContext.Current.Session["token"]; client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token); var wn = GetWerknemerById(wnID); //var wnc = wn.CompetentiesWerknemer.Select(c => c) // .Where(c => c.ID == WNC) // .FirstOrDefault(); detail.CompetentieWerknemerID = WNC; //wnc.CompetentieWerknemerDetail = detail; var url = String.Format(URL + "PutDetails?id=" + WNC); var json = JsonConvert.SerializeObject(detail, new JsonSerializerSettings() { ReferenceLoopHandling = ReferenceLoopHandling.Ignore }); var response = await client.PutAsync( url, new StringContent(json, Encoding.UTF8, "application/json")); } }

或使用同步API，例如 WebClient .

Or use a synchronous API, such as exposed by WebClient.