private void InnerRemove(TypedEventHandler <TSender, TResult> handler, Func <EventRegistrationToken> token)
{
// Check if we handlers
bool wasNull = (eventTable.InvocationList == null);
// Remove
if (handler != null)
{
eventTable.RemoveEventHandler(handler);
}
else
{
eventTable.RemoveEventHandler(token());
}
// Notify of remove
if (observer != null)
{
observer.Removed(this);
}
// If last handler, notify
if ((!wasNull) && (eventTable.InvocationList == null))
{
if (lastRemoved != null)
{
lastRemoved();
}
if (observer != null)
{
observer.LastRemoved(this);
}
}
}
public void RemoveEventHandler_Token_RemovesFromTable()
{
EventHandler handler = new EventHandler(EventHandlerMethod1);
var tokenTable = new EventRegistrationTokenTable <Delegate>();
EventRegistrationToken token = tokenTable.AddEventHandler(handler);
tokenTable.RemoveEventHandler(token);
Assert.Null(tokenTable.InvocationList);
// Calls to RemoveEventHandler after removal are nops.
tokenTable.RemoveEventHandler(token);
}
public void RemoveEventHandler_MultipleTimes_RemovesSingleDelegateFromTable()
{
EventHandler handler = new EventHandler(EventHandlerMethod1);
var tokenTable = new EventRegistrationTokenTable <Delegate>();
tokenTable.AddEventHandler(handler);
tokenTable.AddEventHandler(handler);
tokenTable.RemoveEventHandler(handler);
Assert.Equal(new Delegate[] { handler }, tokenTable.InvocationList.GetInvocationList());
tokenTable.RemoveEventHandler(handler);
Assert.Null(tokenTable.InvocationList);
}
// void PropertyChanged.remove(EventRegistrationToken token)
private void remove_CanExecuteChanged(EventRegistrationToken token)
{
ICommand _this = Unsafe.As <ICommand>(this);
EventRegistrationTokenTable <EventHandler> table = s_weakTable.GetOrCreateValue(_this);
if (table.RemoveEventHandler(token, out EventHandler handler))
{
_this.CanExecuteChanged -= handler;
}
}
// void PropertyChanged.remove(EventRegistrationToken token)
internal void remove_PropertyChanged(EventRegistrationToken token)
{
INotifyPropertyChanged _this = Unsafe.As <INotifyPropertyChanged>(this);
EventRegistrationTokenTable <PropertyChangedEventHandler> table = s_weakTable.GetOrCreateValue(_this);
if (table.RemoveEventHandler(token, out PropertyChangedEventHandler handler))
{
_this.PropertyChanged -= handler;
}
}
public void AddEventHandler_Null_ReturnsZeroToken()
{
var tokenTable = new EventRegistrationTokenTable <Delegate>();
EventRegistrationToken token = tokenTable.AddEventHandler(null);
Assert.Equal(0, token.GetHashCode());
// Removing this token should be a nop.
tokenTable.RemoveEventHandler(token);
}
// void CollectionChanged.remove(EventRegistrationToken token)
internal void remove_CollectionChanged(EventRegistrationToken token)
{
INotifyCollectionChanged _this = Unsafe.As <INotifyCollectionChanged>(this);
EventRegistrationTokenTable <NotifyCollectionChangedEventHandler> table = s_weakTable.GetOrCreateValue(_this);
if (table.RemoveEventHandler(token, out NotifyCollectionChangedEventHandler? handler))
{
_this.CollectionChanged -= handler;
}
}
public void RemoveEventHandler_Delegate_RemovesFromTable()
{
EventHandler handler1 = new EventHandler(EventHandlerMethod1);
EventHandler handler2 = new EventHandler(EventHandlerMethod2);
EventHandler combinedHandler = (EventHandler)Delegate.Combine(handler1, handler2);
var tokenTable = new EventRegistrationTokenTable <Delegate>();
tokenTable.AddEventHandler(combinedHandler);
tokenTable.RemoveEventHandler(handler1);
tokenTable.RemoveEventHandler(handler2);
Assert.Equal(new Delegate[] { handler1, handler2 }, tokenTable.InvocationList.GetInvocationList());
tokenTable.RemoveEventHandler(combinedHandler);
Assert.Null(tokenTable.InvocationList);
// Calls to RemoveEventHandler after removal are nops.
tokenTable.RemoveEventHandler(combinedHandler);
}
public void RemoveEventHandler_NullDelegate_Nop()
{
var tokenTable = new EventRegistrationTokenTable <Delegate>();
tokenTable.RemoveEventHandler(null);
}