WPCordovaClassLib.CordovaView.page_BackKeyPress C# (CSharp) Method

        void page_BackKeyPress(object sender, CancelEventArgs e)
        {
            if (OverrideBackButton)
            {
                try
                {
                    CordovaBrowser.InvokeScript("eval", new string[] { "cordova.fireDocumentEvent('backbutton');" });
                    e.Cancel = true;
                }
                catch (Exception ex)
                {
                    Console.WriteLine("Exception while invoking backbutton into cordova view: " + ex.Message);
                }
            }
            else
            {
                try
                {
                    PageDidChange = false;

                    Uri uriBefore = this.Browser.Source;
                    // calling js history.back with result in a page change if history was valid.
                    CordovaBrowser.InvokeScript("eval", new string[] { "(function(){window.history.back();})()" });

                    Uri uriAfter = this.Browser.Source;

                    e.Cancel = PageDidChange || (uriBefore != uriAfter);
                }
                catch (Exception)
                {
                    e.Cancel = false; // exit the app ... ?
                }
            }
        }