Global exception handling

Context: Global exception handling catches exceptions that are not handled by application code. Different environments have different mechanisms: ASP.NET Core uses middleware, desktop applications use AppDomain.UnhandledException, and tasks use TaskScheduler.UnobservedTaskException. Global handlers are typically used for logging, displaying friendly error messages, and performing cleanup before shutdown.

Usage Example (Console App)

using System;

class Program
{
    static void Main()
    {
        AppDomain.CurrentDomain.UnhandledException += (sender, e) =>
        {
            Console.WriteLine($"Unhandled exception: {e.ExceptionObject}");
            // Log and possibly shutdown gracefully
        };

        throw new Exception("Something went wrong!");
    }
}

Output console

dotnet run
Unhandled exception: System.Exception: Something went wrong!
   at Program.Main(String[] args)

Important notes

• Global handlers cannot prevent application termination (in most cases).
• They are a last resort; prefer handling exceptions locally.
• In ASP.NET Core, middleware is the recommended approach.

Real-world usage example

Desktop application – Log any unhandled exception to a file and show a user‑friendly dialog.
See .NET docs on global exception handling.

Related sections

• 12.5.1 ASP.NET Core middleware
• 12.5.2 AppDomain UnhandledException
• 12.5.3 TaskScheduler UnobservedTaskException