private static EventListenerList CreateWeakListener(object target, object state)
{
var eventInfo = (EventInfo)state;
var listenerInternal = new EventListenerList();
object handler = eventInfo.EventHandlerType == typeof(EventHandler)
? new EventHandler(listenerInternal.Raise)
: ServiceProvider.ReflectionManager.TryCreateDelegate(eventInfo.EventHandlerType,
listenerInternal, EventListenerList.RaiseMethod);
if (handler == null)
{
return(EventListenerList.EmptyListener);
}
#if NET_STANDARD
var addMethod = eventInfo.AddMethod;
#else
var addMethod = eventInfo.GetAddMethod(true);
#endif
if (addMethod == null)
{
return(EventListenerList.EmptyListener);
}
addMethod.InvokeEx(target, handler);
return(listenerInternal);
}
private static EventListenerList CreateContextListener(object src, object state)
{
var context = (IBindingContext)state;
var listenerInternal = new EventListenerList();
context.ValueChanged += listenerInternal.Raise;
return(listenerInternal);
}
public void Dispose()
{
EventListenerList listener = _eventListener;
var weakItem = _weakItem;
if (listener != null && !weakItem.IsEmpty)
{
_eventListener = null;
_weakItem = WeakEventListenerWrapper.Empty;
listener.Remove(weakItem);
}
}
private IDisposable AddInternal(WeakEventListenerWrapper weakItem, string path)
{
lock (this)
{
if (_listeners.Length == 0)
{
_listeners = new[] { new KeyValuePair <WeakEventListenerWrapper, string>(weakItem, path) };
_size = 1;
_removedSize = 0;
}
else
{
if (_removedSize == 0)
{
if (_size == _listeners.Length)
{
EventListenerList.EnsureCapacity(ref _listeners, _size, _size + 1);
}
_listeners[_size++] = new KeyValuePair <WeakEventListenerWrapper, string>(weakItem, path);
}
else
{
for (int i = 0; i < _size; i++)
{
if (_listeners[i].Key.IsEmpty)
{
_listeners[i] = new KeyValuePair <WeakEventListenerWrapper, string>(weakItem, path);
--_removedSize;
break;
}
}
}
}
}
return(new Unsubscriber(this, weakItem, path));
}
static EventListenerList()
{
RaiseMethod = typeof(EventListenerList).GetMethodEx(nameof(Raise), MemberFlags.Public | MemberFlags.Instance);
EmptyListener = new EventListenerList(true);
}
public Unsubscriber(EventListenerList eventListener, WeakEventListenerWrapper weakItem)
{
_eventListener = eventListener;
_weakItem = weakItem;
}
