需求說明：

由於介面大小限制，我們寫完listview或者recyclerView展現圖片後已經佔據了整個螢幕，螢幕下方還有個button，我們需要在滑動圖片的時候button隱藏，出現圖片的時候展現button。

需求分析：

一、給receycleview新增滑動監聽事件

二、給button新增動畫效果

需求實現：

一、我們要實現滑動監聽

//定義自動隱藏監聽內部類，實現recycleView滑動監聽
public AutoHideListener(Activity activity, View view, Animation hide, int hideDuration, Animation show, int showDuration) {
            _ref = new WeakReference<>(activity);
            _view = view;
            _hide = hide;
            _hideDuration = hideDuration;
            _show = show;
            _showDuration = showDuration;
        }

        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            final Activity activity = _ref.get();
            if (activity == null) return;

            switch (newState) {
                case RecyclerView.SCROLL_STATE_IDLE:
                    doOnIdle(activity);
                    break;
                case RecyclerView.SCROLL_STATE_DRAGGING :
                case RecyclerView.SCROLL_STATE_SETTLING:
                    LogUtil.d("SCROLL_STATE_SETTLING");
                    doOnScroll(activity);
                    break;
            }
            //_onScrollChange = false;
        }

        private void doOnScroll(final Activity activity) {
            if (_state != Hide) {
                new Thread() {
                    @Override
                    public void run() {
                        super.run();
                        if (_onScrollChange) {
                            activity.runOnUiThread(new Runnable() {
                                @Override
                                public void run() {
                                    _state = Hide;
                                    _view.setClickable(false);
                                    _view.startAnimation(_hide);
                                }
                            });
                        }
                    }
                }.start();
            }
        }

        private void doOnIdle(final Activity activity) {
            _onScrollChange = false;
            if (_state != Show) {
                if (_idleThread != null) {
                    synchronized (this) {
                        _idleTime = DefaultIdleTime;
                    }
                } else {
                    _idleTime = DefaultIdleTime;
                    _idleThread = new Thread() {
                        @Override
                        public void run() {
                            super.run();
                            synchronized (this) {
                                while (_idleTime > 0) {
                                    _idleTime -= 100;
                                    SystemClock.sleep(100);
                                }
                            }
                            activity.runOnUiThread(new Runnable() {
                                @Override
                                public void run() {
                                    _view.setClickable(true);
                                    _view.startAnimation(_show);
                                }
                            });
                            SystemClock.sleep(_showDuration);
                            _state = Show;
                            _idleThread = null;
                        }
                    };
                    _idleThread.start();
                }
            }
        }

        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            super.onScrolled(recyclerView, dx, dy);
            _onScrollChange = true;
        }
    }
 

二、實現監聽方法

private static void setViewAutoHide(final Activity activity, final View view, final RecyclerView list) {
        view.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @SuppressLint("NewApi")
            @Override
            public void onGlobalLayout() {
                view.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                int height = view.getMeasuredHeight() + 2;
                Log.i("TAGAAA", "height=" + height);
                final TranslateAnimation hide = new TranslateAnimation(0, 0, 0, height);
                final int hideDuration = 250;
                hide.setDuration(hideDuration);
                AccelerateDecelerateInterpolator i = new AccelerateDecelerateInterpolator();
                hide.setInterpolator(i);
                hide.setFillAfter(true);
                final TranslateAnimation show = new TranslateAnimation(0, 0, height, 0);
                final int showDuration = 250;
                show.setDuration(showDuration);
                show.setInterpolator(i);
                show.setFillAfter(true);
                list.addOnScrollListener(new AutoHideListener(activity, view, hide, hideDuration, show, showDuration));
            }
        });
    }
 

三、呼叫方法

setViewAutoHide(this, btTextWantUpdate,recyclerView);

小節：

實現方法有多種，不過我剛好用到了他，大家共同學習進步