c# - 在 Controller 外部将HttpResponseMessage转换为HttpActionResult的最简单方法

Question

实现IExceptionHandler时，结果是IHttpActionResult，但是createResponse返回HttpResponseMessage。我只想从请求上下文创建响应消息。它进行内容协商，我希望使用已经存在的东西，而不是自己创建实现IHttpActionResult的自定义模型。

Controller 可以访问帮助程序，以轻松地将HttpResponseMessage转换为HttpActionResult，但是我在 Controller 之外找不到任何东西。我最好的选择是什么？

var myCustomException = context.Exception as MyCustomException;

if (myCustomException != null)
{
   context.Result = context.Request.CreateResponse(myCustomException.StatusCode, 
                                                   myCustomException.Error);
   return;
}

context.Result = context.Request.CreateResponse(HttpStatusCode.InternalServerError, 
                                                new MyCustomError("Something went wrong"));

Answer 1

MSDN页面将帮助您:https://docs.microsoft.com/en-us/aspnet/web-api/overview/error-handling/web-api-global-error-handling

您需要一个全局错误处理程序。这是核心代码，您将在MSDN页面中找到详细信息。

class OopsExceptionHandler : ExceptionHandler
{
    public override void HandleCore(ExceptionHandlerContext context)
    {
        context.Result = new TextPlainErrorResult
        {
            Request = context.ExceptionContext.Request,
            Content = "Oops! Sorry! Something went wrong." +
                      "Please contact support@contoso.com so we can try to fix it."
        };
    }

    private class TextPlainErrorResult : IHttpActionResult
    {
        public HttpRequestMessage Request { get; set; }

        public string Content { get; set; }

        public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken)
        {
            HttpResponseMessage response = 
                             new HttpResponseMessage(HttpStatusCode.InternalServerError);
            response.Content = new StringContent(Content);
            response.RequestMessage = Request;
            return Task.FromResult(response);
        }
    }
}

顺便说一句，您应该提到MVC版本:

IHttpActionResult在ASP.NET Core 2中被IActionResult替换:

ExceptionHandlerContext位于System.Web.Http中，也不再存在。
这是详细信息:https://docs.microsoft.com/en-us/aspnet/core/migration/webapi?view=aspnetcore-2.1#migrate-models-and-controllers