private void SwapFromViewController(UIViewController fromViewController,
UIViewController toViewController)
{
fromViewController.WillMoveToParentViewController(null);
toViewController.View.Frame = SourceViewController.View.Bounds;
SourceViewController.AddChildViewController(toViewController);
SourceViewController.Transition(fromViewController,
toViewController,
0.3,
UIViewAnimationOptions.TransitionCrossDissolve,
() => { },
(bool finished) =>
{
fromViewController.RemoveFromParentViewController();
toViewController.DidMoveToParentViewController(SourceViewController);
var containerViewController = SourceViewController as ITransitioningViewController;
if (containerViewController != null)
{
containerViewController.ViewChanging.TrySetResult(true);
}
});
}
void AddInitialViewController(UIViewController viewController)
{
// first run no transition animation
SourceViewController.AddChildViewController(viewController);
viewController.View.Frame = SourceViewController.View.Bounds;
SourceViewController.Add(viewController.View);
viewController.DidMoveToParentViewController(SourceViewController);
var containerViewController = SourceViewController as ITransitioningViewController;
if (containerViewController != null)
{
containerViewController.ViewChanging.TrySetResult(true);
}
}
public override void Perform()
{
var containerView = ((IContainerController)SourceViewController).ContainerView;
var previous = SourceViewController.ChildViewControllers.Last();
if (previous != null && previous.GetType() != typeof(TabBarController))
{
previous.RemoveFromParentViewController();
previous.View.RemoveFromSuperview();
}
SourceViewController.AddChildViewController(DestinationViewController);
containerView.AddSubview(DestinationViewController.View);
DestinationViewController.DidMoveToParentViewController(SourceViewController);
DestinationViewController.View.TranslatesAutoresizingMaskIntoConstraints = false;
DestinationViewController.View.LeadingAnchor.ConstraintEqualTo(containerView.LeadingAnchor).Active = true;
DestinationViewController.View.TrailingAnchor.ConstraintEqualTo(containerView.TrailingAnchor).Active = true;
DestinationViewController.View.TopAnchor.ConstraintEqualTo(containerView.TopAnchor).Active = true;
DestinationViewController.View.BottomAnchor.ConstraintEqualTo(containerView.BottomAnchor).Active = true;
}