Is it possible to catch unexpected errors globally in c# WPF apllication - c# 4.0

Question

Is it possible to catch unexpected errors globally in c# WPF application - c# 4.0

I found that DispatcherUnhandledException was able to catch UI thread errors but actually i need TPL threads. UnhandledException was able to catch thread errors but it was still causing software to terminate.

So any solution to catch unhandled exceptions in the threads not in UI thread and still let software to run not terminate. Threads are TPL threads. (Task Parallel Library)

possible duplicate of [How to handle all unhandled exceptions when using Task Parallel Library?](http://stackoverflow.com/questions/2707295/how-to-handle-all-unhandled-exceptions-when-using-task-parallel-library) — Jon, Oct 22 '11 at 13:21

score 2 · Accepted Answer · answered Oct 22 '11 at 12:52

2

A part from handling DispatcherUnhandledException which you already have done add this to your config file

<configuration>
  <runtime>  
    <legacyUnhandledExceptionPolicy enabled="1"/>
  </runtime>
</configuration>

This prevents your secondary threads exception from shutting down the application.

answered Oct 22 '11 at 12:52

Haris Hasan

29,856
10
92
122

so i can use this and UnhandledException to catch errors and let software continue am i correct ? but where do i put it ? it is wpf not asp.net – Furkan Gözükara Oct 22 '11 at 13:35
In your app.config file which not only exists in ASP.Net apps. It will only allow you not quit app in case of an exception. I am not sure how how will you catch them – Haris Hasan Oct 22 '11 at 13:50
where is this config file i don't see anywhere. i have app.xaml but it gives error when i put it there – Furkan Gözükara Oct 22 '11 at 13:54
Right click on your project -> add new item-> application configuration file – Haris Hasan Oct 22 '11 at 14:03
thanks. i also add this and i think both will solve problem. AppDomain.CurrentDomain.UnhandledException += new UnhandledExceptionEventHandler(MyExceptionHandler); – Furkan Gözükara Oct 22 '11 at 19:20

score 1 · Answer 2 · answered Oct 22 '11 at 18:40

You can use Custom Escalation Policy in TPL to address your case.You do this by adding an event handler to the static System.Threading.Tasks.TaskScheduler.UnobservedTaskException member

    class Test
    {
        static void Main(string[] args)
        {
            // create the new escalation policy
            TaskScheduler.UnobservedTaskException += (object sender, UnobservedTaskExceptionEventArgs eventArgs) =>
             {
                // mark the exception as being handled
                eventArgs.SetObserved();
                // get the aggregate exception and process the contents
                 ((AggregateException)eventArgs.Exception).Handle(ex =>
                    {
                        // write the type of the exception to the console
                         Console.WriteLine("Exception type: {0}", ex.GetType());
                        return true;
                    });
              };
            // create tasks that will throw an exception
            Task task1 = new Task(() =>
            {
                throw new NullReferenceException();
            });
            Task task2 = new Task(() =>
            {
                throw new ArgumentOutOfRangeException();
            });
            // start the tasks
            task1.Start(); task2.Start();
            // wait for the tasks to complete - but do so
            // without calling any of the trigger members
            // so that the exceptions remain unhandled
            while (!task1.IsCompleted || !task2.IsCompleted)
            {
                Thread.Sleep(500);
            }
            // wait for input before exiting
            Console.WriteLine("Press enter to finish and finalize tasks");
            Console.ReadLine();
        }
    }
}

Is it possible to catch unexpected errors globally in c# WPF apllication - c# 4.0

2 Answers2