AppDomain.UnhandledException Event

Definition

Occurs when an exception is not caught.

public event UnhandledExceptionEventHandler? UnhandledException;
public event UnhandledExceptionEventHandler UnhandledException;
[add: System.Security.SecurityCritical]
[remove: System.Security.SecurityCritical]
public event UnhandledExceptionEventHandler UnhandledException;

Event Type

Implements

Attributes

Examples

The following example demonstrates the UnhandledException event. It defines an event handler, MyHandler, that is invoked whenever an unhandled exception is thrown in the default application domain. It then throws two exceptions. The first is handled by a try/catch block. The second is unhandled and invokes the MyHandle routine before the application terminates.

using System;

public class Example
{
   public static void Main()
   {
      AppDomain currentDomain = AppDomain.CurrentDomain;
      currentDomain.UnhandledException += new UnhandledExceptionEventHandler(MyHandler);

      try {
         throw new Exception("1");
      } catch (Exception e) {
         Console.WriteLine("Catch clause caught : {0} \n", e.Message);
      }

      throw new Exception("2");
   }

   static void MyHandler(object sender, UnhandledExceptionEventArgs args)
   {
      Exception e = (Exception) args.ExceptionObject;
      Console.WriteLine("MyHandler caught : " + e.Message);
      Console.WriteLine("Runtime terminating: {0}", args.IsTerminating);
   }
}
// The example displays the following output:
//       Catch clause caught : 1
//
//       MyHandler caught : 2
//       Runtime terminating: True
//
//       Unhandled Exception: System.Exception: 2
//          at Example.Main()

Remarks

For more information about this API, see Supplemental API remarks for UnhandledException.

Applies to

Product Versions
.NET Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1