System.ArgumentException Occurs With WindowsFormsHost in WPF Application

You can work around this behavior in these ways.

1. Do not programmatically remove controls from the WindowsFormsHost element. Instead, hide them by setting their Visible property.

2. Wire an eventhandler to the System.Windows.Forms.Application.ThreadException event. This will allow you to suppress the Windows Forms exception dialog. The code can check specifically to see if the exception is a System.ArgumentException from System.Windows.Forms, that contains "System.Windows.Forms.Integration.WindowsFormsHost.RestoreFocusedChild" in its call stack. If not, then display the standard Windows Forms exception dialog box.


        public MainWindow()
        {
            System.Windows.Forms.Application.ThreadException += new System.Threading.ThreadExceptionEventHandler(Application_ThreadException);
        }

        void Application_ThreadException(object sender, System.Threading.ThreadExceptionEventArgs e)
        {
            if (!FailureFromFocusedChild(e.Exception))
            {
                System.Windows.Forms.Application.ThreadExceptionDialog dlg;
                dlg = new System.Windows.Forms.Application.ThreadExceptionDialog(e.Exception);
                dlg.ShowDialog();
            }

        private bool FailureFromFocusedChild(Exception e)
        {
            bool result = false;
            string stackTrace = e.StackTrace;
           
            result = (e is System.ArgumentException) && (e.Source == "System.Windows.Forms")
                    && (stackTrace.IndexOf("System.Windows.Forms.Integration.WindowsFormsHost.RestoreFocusedChild")>=0);


            return result;
        }