ASP.NET Core 응용 오류 처리 Developer ExceptionPageMiddleware 미들웨어 에서'개발 자 이상 페이지'표시

 public class DeveloperExceptionPageOptions
 {
  public IFileProvider  FileProvider { get; set; }
  public int    SourceCodeLineCount { get; set; }
 }

 public static class DeveloperExceptionPageExtensions
 { 
  public static IApplicationBuilder UseDeveloperExceptionPage(this IApplicationBuilder app)
  {
   return app.UseMiddleware<DeveloperExceptionPageMiddleware>();
  } 
  public static IApplicationBuilder UseDeveloperExceptionPage(this IApplicationBuilder app,DeveloperExceptionPageOptions options)
  {
   return app.UseMiddleware<DeveloperExceptionPageMiddleware>(Options.Create(options));
  }
 }

 public class DeveloperExceptionPageMiddleware
 {
  private RequestDelegate _next;
  public async Task Invoke(HttpContext context)
  {
   try
   {
    await _next(context);
   }
   catch(Exception ex)
   {
    context.Response.Clear();
    context.Response.StatusCode = 500;
 
    ICompilationException compilationException = ex as ICompilationException;
    if (null != compilationException)
    {
     await DisplayCompilationException(context, compilationException);
    }
    else
    {
     await DisplayRuntimeException(context, ex);
    }
   }
  }
 
  private Task DisplayRuntimeException(HttpContext context, Exception ex);
  private Task DisplayCompilationException(HttpContext context,ICompilationException compilationException) ;
 }

 public class Program
 {
  public static void Main()
  {
   new WebHostBuilder()
    .UseKestrel()
    .UseContentRoot(Directory.GetCurrentDirectory())
    .ConfigureServices(svcs => svcs.AddMvc())
    .Configure(app => app
     .UseDeveloperExceptionPage()
     .UseMvc())
    .Build()
    .Run();
  }
 }
 
 public class HomeController : Controller
 {
  [HttpGet("/")]
  public IActionResult Index()
  {
   return View();
  }
}

 @{ 
  var value = new Foobar();
 }

 public interface ICompilationException
 {
  IEnumerable<CompilationFailure> CompilationFailures { get; }
 }
 
 public class CompilationFailure
 {
  public string        SourceFileContent { get; }
  public string        SourceFilePath { get; }
  public string        CompiledContent { get; }
  public IEnumerable<DiagnosticMessage>  Messages { get; }
  …
 }

 public class DiagnosticMessage
 {
  public string  SourceFilePath { get; }
  public int  StartLine { get; }
  public int  StartColumn { get; } 
  public int  EndLine { get; }
  public int  EndColumn { get; }
 
  public string  Message { get; }  
  public string  FormattedMessage { get; } 
 …
 }

 public class Program
 {
  public static void Main()
  {
   new WebHostBuilder()
    .UseKestrel()
    .UseContentRoot(Directory.GetCurrentDirectory())
    .ConfigureServices(svcs => svcs.AddMvc())
    .Configure(app => app
     .UseDeveloperExceptionPage(new DeveloperExceptionPageOptions { SourceCodeLineCount = 3 })
     .UseMvc())
    .Build()
    .Run();
  }
 }

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 public class Program
 {
  public static void Main()
  {
   new WebHostBuilder()
    .UseKestrel()
    .Configure(app => app
     .UseDeveloperExceptionPage()
     .Run(Invoke))
    .Build()
    .Run();
  }
  private static Task Invoke(HttpContext context)
  {
   throw new InvalidOperationException("Manually thrown exception");
  }
 }