Esempio n. 1
0
        private void fireAutomationEvents()
        {
            //no reentrancy. It may happen if one of handlers calls UpdateLayout synchronously
            if (_inFireAutomationEvents)
            {
                return;
            }

            EventTrace.EasyTraceEvent(EventTrace.Keyword.KeywordLayout, EventTrace.Level.Verbose, EventTrace.Event.WClientLayoutFireAutomationEventsBegin);
            try
            {
                _inFireAutomationEvents = true;
                _firePostLayoutEvents   = false;

                LayoutEventList.ListItem [] copy = AutomationEvents.CopyToArray();

                for (int i = 0; i < copy.Length; i++)
                {
                    LayoutEventList.ListItem item = copy[i];
                    //store peer here in case if thread gets pre-empted between check for IsAlive and invocation
                    //and GC can run making something that was alive not callable.
                    AutomationPeer peer = null;
                    try
                    {
                        // this will return null if element is already GC'ed
                        peer = (AutomationPeer)(item.Target);
                    }
                    catch (InvalidOperationException) //this will happen if element is being resurrected after finalization
                    {
                        peer = null;
                    }

                    if (peer != null)
                    {
                        peer.FireAutomationEvents();
                        // if handler dirtied the tree, go clean it again before calling other handlers
                        if (hasDirtiness)
                        {
                            break;
                        }
                    }
                    else
                    {
                        AutomationEvents.Remove(item);
                    }
                }
            }
            finally
            {
                _inFireAutomationEvents = false;
                EventTrace.EasyTraceEvent(EventTrace.Keyword.KeywordLayout, EventTrace.Level.Verbose, EventTrace.Event.WClientLayoutFireAutomationEventsEnd);
            }
        }