C# HttpClient - PutAsync

Question

我有一个后端控制器方法

[Route("{ropeId}/segments")]
[HttpPut]
public async Task<IActionResult> Put([NotNull] [FromBody] IEnumerable<Segment> segments)
{
    Debug.WriteLine("In here!");
}

我可以使用Rider中的草稿本轻松实现这个：

PUT https://localhost:6001/api/ropes/3/segments
Accept: */*
Cache-Control: no-cache
Content-Type: application/json

[{"SegmentNo":1,"RopeId":3,"LastReceived":"2019-12-28T14:34:35.9799039+01:00","BendDamage":0.018,"Temperature":30.0,"LoadLevel":1},
{"SegmentNo":16,"RopeId":3,"LastReceived":"2019-12-28T14:34:35.9799039+01:00","BendDamage":0.018,"Temperature":30.0,"LoadLevel":1}, {"SegmentNo":50,"RopeId":3,"LastReceived":"2019-12-28T14:34:35.9799039+01:00","BendDamage":0.018,"Temperature":30.0,"LoadLevel":1},
{"SegmentNo":69,"RopeId":3,"LastReceived":"2019-12-28T14:34:35.9799039+01:00","BendDamage":0.018,"Temperature":30.0,"LoadLevel":1},
{"SegmentNo":101,"RopeId":3,"LastReceived":"2019-12-28T14:34:35.9799039+01:00","BendDamage":0.018,"Temperature":30.0,"LoadLevel":1},  {"SegmentNo":106,"RopeId":3,"LastReceived":"2019-12-28T14:34:35.9799039+01:00","BendDamage":0.018,"Temperature":30.0,"LoadLevel":1},
{"SegmentNo":128,"RopeId":3,"LastReceived":"2019-12-28T14:34:35.9799039+01:00","BendDamage":0.018,"Temperature":30.0,"LoadLevel":1}]

分段模型：

public sealed class Segment
{
   public Segment(short segmentNo,
                  byte ropeId,
                  DateTime lastReceived,
                  double bendDamage,
                  double temperature,
                  byte loadLevel)
   {
      SegmentNo = segmentNo;
      RopeId = ropeId;
      LastReceived = lastReceived;
      BendDamage = bendDamage;
      Temperature = temperature;
      LoadLevel = loadLevel;
   }

   public short SegmentNo { get; }
   public byte RopeId { get; }
   public DateTime LastReceived { get; }
   public double BendDamage { get; }
   public double Temperature { get; }
   public byte LoadLevel { get; }
}

我无法使用httpClient PutAsync调用。

我尝试过：

var httpContent = new StringContent(updatedSegments);
var response = await httpClient.PutAsync(@"https://localhost:6001/api/ropes/3/segments", httpContent);

但是我遇到了一个“序列化错误”。

Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker[1]
Route matched with {action = "Put", controller = "Ropes"}. Executing action WEBAPI.Controllers.RopesController.Put (WEBAPI)
info: Microsoft.AspNetCore.Mvc.Infrastructure.ObjectResultExecutor[1]
Executing ObjectResult, writing value of type 'Microsoft.AspNetCore.Mvc.SerializableError'.

我的PutAsync调用有什么问题？

就像我说的，在Postman / PUT scratch中可以正常工作。

如果我执行

var s = await httpContent.ReadAsStringAsync();
s.Print();

我得到了上述JSON，所以我认为问题在于我需要在httpContent上设置某种头来告诉它它是application/json格式的。

- Stuart

---

尝试像这样指定httpContent的构建内容类型，对我来说效果很好： var httpContent = new StringContent(updatedSegments.ToString(Newtonsoft.Json.Formatting.None), Encoding.UTF8, "application/json"); - Dr. Roggia

搞定了，谢谢！ - Stuart

Answer 1

你尝试在httpContent对象的构造函数中指定内容类型了吗？我曾经使用httpClient调用并声明类型，就像这样：

var httpContent= new StringContent(updatedSegments.ToString(Newtonsoft.Json.Formatting.None), Encoding.UTF8, "application/json");

如果这对你也有帮助，请告诉我。

- Dr. Roggia