How to pass the exception from exception handling middleware to ErrorController in ASP.NET Core MVC web application?

Question

I developed a global exception handling middleware and tried to pass my exception to the ErrorCotroller in my ASP.NET Core MVC application.

Middleware:

public class GlobalExceptionHandlingMiddleware
{
    private readonly RequestDelegate _next;         

    public GlobalExceptionHandlingMiddleware(RequestDelegate request)
    {
        _next = request; 
    }

    public async Task Invoke(HttpContext httpContext)
    {
        try
        {
            await _next(httpContext);
        }
        catch(Exception ex)
        {
            await HandleExceptionAsync(httpContext, ex);
        }
    }

    private async Task HandleExceptionAsync(HttpContext httpContext, Exception ex)
    {           
        httpContext.Response.Redirect("/Error/Error");
        httpContext.Items["exception"] = ex;
    }
} 

ErrorController:

public class ErrorController : Controller
{
    private readonly ILogger<ErrorController> _logger;

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

    [Route("/Error/Error")]
    public IActionResult Error()
    {
        Exception exec = (Exception)HttpContext.Items["exception"];
        ViewData["message"] = exec.Message;
        _logger.LogError(exec, "Internal server error");
        return View("Error");
    }  
}

I tried to use HttpContext.Items["exception"] to pass the exception to the ErrorController, but that was not successful.

How can I achieve this?

Answer 1

Change your middleware like below, it works for me.

And I am not familiar with your logic, you can modify it as you needed.

Test Result

GlobalExceptionHandlingMiddleware.cs

namespace AspCore7_Web_Identity
{
    public class GlobalExceptionHandlingMiddleware
    {
        private readonly RequestDelegate _next;

        public GlobalExceptionHandlingMiddleware(RequestDelegate next)
        {
            _next = next;
        }

        public async Task Invoke(HttpContext httpContext)
        {
            try
            {
                // Just for testing in my local
                //await HandleExceptionAsync(httpContext, new Exception("test exceptions"));
                await _next(httpContext);
            }
            catch (Exception ex)
            {
                await HandleExceptionAsync(httpContext, ex);
            }
        }

        private async Task HandleExceptionAsync(HttpContext httpContext, Exception ex)
        {
            httpContext.Items["exception"] = ex;

            PathString originalPath = httpContext.Request.Path;
            QueryString originalQueryString = httpContext.Request.QueryString;

            try
            {
                httpContext.Request.Path = "/Error/Error";
                httpContext.Request.QueryString = QueryString.Empty;

                await _next(httpContext);
            }
            finally
            {
                httpContext.Request.Path = originalPath;
                httpContext.Request.QueryString = originalQueryString;
            }
        }
    }

}

Register middlware here