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Frinavale's questions

Martin Hope
Frinavale
Asked: 2025-02-15 03:07:37 +0800 CST
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我目前正在学习 ASP.NET Core Web API 项目中的错误错误管理，以尝试找到一个优雅的解决方案，确保ProblemDetails在出现问题时始终返回。

我正在使用WeatherForecast创建带有控制器的新 C# / ASP.NET Core 8 Web API 项目时创建的默认 API 模板。

我已经实现了自定义异常处理程序；然而我发现它并不总是有效。

当我使用 调用 APIPostman导致错误时，我得到了正确的ProblemDetails、状态代码和标头信息；但是，当我从界面中的“试用”功能调用 API 时Swagger，我得到了错误的状态代码（500 内部错误）以及异常详细信息而不是ProblemDetails和错误的标头信息。

研究这个问题，我发现在我的GlobalExceptionHandler类（实现IExceptionHandle接口）中，如果我尝试来自 Swagger 的代码，该ProblemDetailsService.TryWriteAsync(...)方法就会返回false；但是，当我通过从 Postman 调用它执行完全相同的代码时，该ProblemDetailsService.TryWriteAsync(...)方法就会返回true。

我提出了一个当“ProblemDetailsS​​ervice.TryWriteAsync(...)”返回失败的情况，以便我可以尝试直接将其ProblemDetailsContext写入httpContext.Response。

当我这样做时，我能够捕获以下异常（再次，这仅在使用 Swagger 的 Try Code 功能时发生......而不是从 Postman 调用时发生）：

不支持对“System.Type”实例进行序列化和反序列化。路径：$.HttpContext.Features.Key。”

我不知道为什么这会失败。

我正在寻求帮助，如何确保无论如何调用 API，我的错误管理都以相同的方式运行。

GlobalExceptionHandler这是我的课程的实现：

public class GlobalExceptionHandler : IExceptionHandler
{
      private readonly IProblemDetailsService _problemDetailsService;

      public GlobalExceptionHandler(IProblemDetailsService problemDetailsService)
      {
          if (problemDetailsService == null) throw new ArgumentException(nameof(problemDetailsService));
          _problemDetailsService = problemDetailsService;
      }

      public async ValueTask<bool> TryHandleAsync(HttpContext httpContext, Exception exception, CancellationToken cancellationToken)
      {
          var message = exception switch
          {
              ArgumentException => ((ArgumentException)exception).Message,
              ValidationException => ((ValidationException)exception).Message,
              _ => $"Internal Server Error ({exception.GetType().Name})"
          };

          int status = exception switch
          {
              ArgumentException => (int)HttpStatusCode.BadRequest,
              ValidationException => (int)HttpStatusCode.BadRequest,
              _ => (int)HttpStatusCode.InternalServerError
          };

          ProblemDetails problemDetails = new()
          {
              Title = $"Bad Request: {exception.GetType().Name}", // human-readable summary of the problem type
              Detail = message, //detailed explanation specific to the problem
              Status = status,
              Instance = httpContext.Request.GetEncodedUrl(),
              Type = exception.HelpLink
          };

          var errorcontext = new ProblemDetailsContext()
          {
              HttpContext = httpContext,
              ProblemDetails = problemDetails,
              //Exception = exception,
              AdditionalMetadata = null
          };

          httpContext.Response.Clear();
          httpContext.Response.StatusCode = status;

          var written = await _problemDetailsService.TryWriteAsync(errorcontext);

          if (!written)
          {
              try
              {
                  await httpContext.Response.WriteAsJsonAsync<ProblemDetailsContext>(errorcontext);
                  written = true;
              }
              catch (Exception ex)
              {
                  Console.WriteLine(ex.ToString());
                  written = false;
              }
          }

          return written;
      }
}

这是我的Program.cs：

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using System.Net;
using System;
using System.ComponentModel.DataAnnotations;
using Microsoft.AspNetCore.Http.Extensions;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using System.Net.Http;
using Microsoft.AspNetCore.Diagnostics;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddControllers();

// Add services to the container.
builder.Services.AddExceptionHandler<ProblemDetailsScratchPad.GlobalExceptionHandler>();   // Using a custom exception handler that converts the exception into a Problem Details
builder.Services.AddProblemDetails();  // required for using the exception handler with the custom problem details exception handler code because it adds the services required for Problem Details

// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

app.UseExceptionHandler(opt => { }); //adding the custom GlobalExceptionHandler to the app's pipeline
app.UseAuthorization();

app.MapControllers();

app.Run();

这是我的实现WeatherForecastController（并不是说调用 post 或 get 会引发异常并由自定义异常处理程序进行处理）

[ApiController]
[Route("[controller]")]
public class WeatherForecastController : ControllerBase
{
    

    private readonly ILogger<WeatherForecastController> _logger;

    public WeatherForecastController(ILogger<WeatherForecastController> logger)
    {
        _logger = logger;
    }

    [HttpGet("GetWeatherForecast")]
    public ActionResult<IEnumerable<object>> GetWeatherForecast()
    {
        
            throw new ArgumentException("Please provide a valid value for a week day: between 0 and 6");

    }

    [HttpPost("PostWeatherForecastDTO")]
    public ActionResult<IEnumerable<object>> PostWeatherForecastDTO()
    {
         throw new Exception("Please provide a valid value for a week day: between 0 and 6");

    }
}
c#