c# - Trying to showing a dialog on DispatcherUnhandledException -

i have wpf application i'm adding top level, catch error handling. handle dispatcherunhandledexception event so:

    private void app_ondispatcherunhandledexception(object sender, dispatcherunhandledexceptioneventargs e)     {         if (_ishandlingerror)         {             _log.error("critical unhandled error", e.exception);             e.handled = true;             return;         }          _ishandlingerror = true;         var vm = _windsorcontainer.resolve<errorreporterviewmodel>();          dispatcher.invoke(() =>         {             vm.details = failuremessagebuilder.createcontent(e.exception);             var view = new errorreporterview { datacontext = vm };              view.show();         });          e.handled = true;          notifyofexception(e.exception, vm.description);          _ishandlingerror = false;     } 

the problem is, call show() (or showdialog) never returns, , error dialog never shown.

what might issue?

do have attached event application?

capp.dispatcher.unhandledexception += new dispatcherunhandledexceptioneventhandler(dispatcher_unhandledexception);                 capp.initializecomponent();                 capp.run(new mainwindow()); 

and then

private static void dispatcher_unhandledexception(object sender, dispatcherunhandledexceptioneventargs e)         { ...e.exception.message }