UITapGestureRecognizer xamarin-多次轻按可快速显示多个视图

Question

I'm having some difficulties solving a problem in xamarin. In ViewDidAppear of my viewcontroller I am registering a tap gesture.

ProfileViewController

public override void ViewDidAppear (bool animated)
        {
            base.ViewDidAppear (animated);
            if (!_hasUi) {
                SetUi ();
            }

            SetProfile ();

            if (CheckConnectivityStatus ()) {

                SetGameData ();

                if (_hasRegisteredGestures) return;
                //SetGestures();
                AssignGesturesToUi();


                _hasRegisteredGestures = true;
            } else {
                HandleWebAPICallError ();
            }
        }


 public void AssignGesturesToUi()
        {

            _bonusTap = new UITapGestureRecognizer(ShowBonus) { CancelsTouchesInView = false };

            _userProfile.VwLevel.MultipleTouchEnabled = false;
            _userProfile.VwLevel.UserInteractionEnabled = true;
            _userProfile.VwLevel.AddGestureRecognizer(_bonusTap);

        }

I then have my ShowBonus method which takes tap as a parameter.

private void ShowBonus (UITapGestureRecognizer tap)
        {
            if (tap.State == UIGestureRecognizerState.Cancelled)
                return;

            _userProfile.VwLevel.UserInteractionEnabled = true;

            //RemoveGestures();
                var tab = TabBarController as GameTabController;
                tab?.SetTabBarVisible(false, true);
                var mainStoryboard = UIStoryboard.FromName("Main", null);
                var achievementsViewController = (AchievementsViewController)mainStoryboard.InstantiateViewController("AchievementsViewController");
                AddChildViewController(achievementsViewController);
                achievementsViewController.Achievements = false;
                achievementsViewController.View.Transform = CGAffineTransform.MakeScale(0.01f, 0.01f);
                achievementsViewController.View.Center = _userProfile.ConvertPointToView(_userProfile.Cup.Center, View);
                achievementsViewController.ReturnPoint = achievementsViewController.View.Center;
                View.AddSubview(achievementsViewController.View);
                achievementsViewController.View.Alpha = 0.0f;
                UIView.Animate(0.5f, 0.0f, UIViewAnimationOptions.CurveEaseInOut,
                    () => {
                        achievementsViewController.View.Transform = CGAffineTransform.MakeScale(1.0f, 1.0f);
                        achievementsViewController.View.Center = View.Center;
                        achievementsViewController.View.Alpha = 1.0f;
                    },
                    () => {
                        achievementsViewController.DidMoveToParentViewController(this);

                    });

        }

Show bonus displays another view infront of the profile view. If I tap the UI quickly it will fire the code twice. Is it possible that even if I tap it multiple times quickly that it only ever fires the code once?

Answer 1

Define variable lastShowPress of type DateTime and store there last time of ShowBonus was called. At the begining of ShowBonus check if ShowBonus was called within let say 10 seconds or whatever interval you need. If it was - return, if not - store the time and execute. You will need to protect this variable/checking by lock object.