How to catch unhandled errors in ASP.NET MVC?

Question

I've created a simple MVC project, add one method:

public class HomeController : Controller
{
    public async Task<string> Index()
    {
        var t = Task.Run(() =>
        {
            Debug.Print("Debug___1");
            throw new Exception("Error #1");
            Debug.Print("Debug___2");
        });
        await Task.Delay(5000);
        return "ASD";
    }
}

Then i run application, get "ASD" output and debug messages:

Debug___1
Exception thrown: 'System.Exception' in WebApplication2.dll

But how can I catch that exception? I've tried creating Application_Error method on global.asas, but it didn't work:

namespace WebApplication2
{
    public class MvcApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);
        }

        protected void Application_Error(object sender, EventArgs e)
        {
            Debug.Print("Catched");
        }
    }
}

Are you looking for a way to catch Exceptions arising from Task.Run? — mahlatse, Jan 31 '19 at 14:34
Have you tried [https://learn.microsoft.com/en-us/dotnet/standard/parallel-programming/exception-handling-task-parallel-library](https://learn.microsoft.com/en-us/dotnet/standard/parallel-programming/exception-handling-task-parallel-library) — mahlatse, Jan 31 '19 at 18:57

score 0 · Answer 1 · answered Jan 31 '19 at 03:02

0

At the controller level, you can deal with unhandled exceptions by overriding the OnException method.

Look at this link for a description: https://www.codeproject.com/Articles/850062/Exception-handling-in-ASP-NET-MVC-methods-explaine

answered Jan 31 '19 at 03:02

Charles Owen

2,403
1
14
25

Doesn't work exceptions in Task.Run(). But works for other exception in a controller. – DTXqueque Jan 31 '19 at 06:11

score 0 · Answer 2 · answered Jan 31 '19 at 13:10

catch(Exception ex)
{
 //create custom error handling method
 ErrorLog(ex);
}

Public static void Errorlog(Exception ex)
{
//creates new txt file to view errordetails
 string strPath = @"D:\ErrorLog.txt";
 File.create(strPath);
 using (StreamWriter sw = File.AppendText(strPath))
 {
   sw.WriteLine("Error Details",+DateTime.Now);
   sw.WriteLine("Error Message: " + ex.Message);
   sw.WriteLine("Stack Trace: " + ex.StackTrace);
 }
}

score 0 · Answer 3 · answered Jan 31 '19 at 21:30

.NET 4 allows you to define how your task will handle exceptions as shown in the following post : catch exception that is thrown in different thread

So in your example above, you would first define your task

Task<string> task = new Task<string>(Test);

then pass in an exception handler

task.ContinueWith(ExceptionHandler, TaskContinuationOptions.OnlyOnFaulted);

then finally define an exception handler somewhere

static void ExceptionHandler(Task<string> task)
{
    var exception = task.Exception;
    //Handle error via ModelState or how you prefer 
}

score 0 · Answer 4 · answered Jun 23 '20 at 13:18

0

Use the HttpServerUtility.HttpApplication.Server object's method GetLastError.

protected void Application_Error(object sender, EventArgs e)
{
    Exception ex = Server.GetLastError();
}

answered Jun 23 '20 at 13:18

Daniel

1,044
11
10

How to catch unhandled errors in ASP.NET MVC?

4 Answers4