.NET API POST端点无法被控制台应用调用问题求助

我有一个.NET API，想用控制台应用测试其中的POST方法。把控制台里的数据序列化成JSON字符串后发送到API，但POST端点始终无法被命中，控制台也没有任何错误提示。不过GET请求正常，只有POST有问题。

using _ErrorLogger.Shared;
using _ErrorLogger.Server.Services;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using System.Runtime.CompilerServices;

namespace _ErrorLogger.Server.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class ExceptionDetailsController : ControllerBase
    {
        private readonly IExceptionDetailsService _exceptionDetailsService;
        public ExceptionDetailsController(IExceptionDetailsService exceptionDetailsService)
        {
            _exceptionDetailsService = exceptionDetailsService;
        }

        [HttpGet]
        [Route("GetExceptions")]
        public async Task<List<ExceptionDetails>> GetAll()
        {
            return await _exceptionDetailsService.GetAllExceptionDetails();
        }

        [HttpGet]
        [Route("GetExceptionByID/{id}")]
         public async Task<ExceptionDetails> GetByID(int id)
        {
            return await _exceptionDetailsService.GetExceptionDetails(id);
        }

        [HttpPost]
        [Route("CreateException")]
        public async Task<IActionResult> CreateException([FromBody]string obj)
        {
            //await _exceptionDetailsService.AddExceptionDetails(exceptionDetails);
            return Ok();
        }

        [HttpPost]
        [Route("Test")]
        public async Task<IActionResult> Test([FromBody] string obj)
        {
            return Ok();
        }
    }
}

public async void ExceptionsAnalyzer(Exception exception)
{
    HttpClient _httpClient = new HttpClient();

    StackTrace stack = new StackTrace(exception, true);

    StackFrame frame = stack.GetFrame(stack.FrameCount - 1);

    ExceptionDetails exceptionDetails = new ExceptionDetails
    {
        ExceptionMessage = exception.Message,
        InnerException = exception.InnerException?.ToString(),
        ExceptionType = exception.GetType().ToString(),
        ExceptionSourceFile = frame.GetFileName(),
        ExceptionSourceLine = frame.GetFileLineNumber().ToString(),
        ExceptionCaller = frame.GetMethod().ToString(),
        ExceptionStackTrace = exception.StackTrace,
        DateLogged = DateTime.Now

    };

    string json = JsonSerializer.Serialize(exceptionDetails);
    //var stringContent = new StringContent(json, Encoding.UTF8, "application/json");

    HttpResponseMessage response = await _httpClient.PostAsJsonAsync("http://localhost:5296/api/ExceptionDetails/CreateException", json);
    if (response.IsSuccessStatusCode)
    {

    }
}

核心问题是请求数据格式与API接收参数不匹配，外加异步代码的潜在问题，具体修复如下：

1. 修正数据格式不匹配问题 #

你的API端点CreateException接收的是[FromBody]string obj，但使用PostAsJsonAsync发送序列化后的exceptionDetails时，会把JSON字符串再次包装成JSON格式（相当于发送了带嵌套引号的字符串，比如"{...}"），导致API无法解析，返回400错误，但你未处理非成功响应所以看不到提示。

有两种修复方案：

方案一（推荐，符合REST规范）：修改API接收对象 #

直接让API接收ExceptionDetails类型，无需手动处理字符串序列化：

[HttpPost]
[Route("CreateException")]
public async Task<IActionResult> CreateException([FromBody] ExceptionDetails exceptionDetails)
{
    await _exceptionDetailsService.AddExceptionDetails(exceptionDetails);
    return Ok();
}

控制台代码无需修改，PostAsJsonAsync会自动正确序列化exceptionDetails对象。

方案二：保持API接收字符串，修正控制台请求方式 #

如果必须保持API接收字符串，改用StringContent发送原始JSON字符串，避免二次序列化：

var stringContent = new StringContent(json, Encoding.UTF8, "application/json");
HttpResponseMessage response = await _httpClient.PostAsync("http://localhost:5296/api/ExceptionDetails/CreateException", stringContent);

2. 修复异步代码隐患 #

• 避免使用async void，改用async Task，否则无法捕获异步操作中的异常：

  public async Task ExceptionsAnalyzer(Exception exception)
  {
      // 原有代码逻辑
  }
  

• 增加错误响应处理，方便排查问题：

  if (!response.IsSuccessStatusCode)
  {
      string errorMsg = await response.Content.ReadAsStringAsync();
      Console.WriteLine($"请求失败：{response.StatusCode}，详情：{errorMsg}");
  }
  

内容的提问来源于stack exchange，提问作者MarkBerry