Viewpager 橫向滑動效果系統(tǒng)就自帶了很多種，比如這個
效果
那如果做成豎屏的這種效果呢 。我百度過很多，效果都不是很好，有的代碼特別多而且存在很多問題。我結(jié)合了以前別人的代碼現(xiàn)在來教大家個簡單的實(shí)現(xiàn)過程。
首先自定義Viewpager 是肯定必不可少的了
public class VerticalViewPager extends ViewPager { private OnItemClickListener mOnItemClickListener; public VerticalViewPager(Context context) { super(context); init(); } public VerticalViewPager(Context context, AttributeSet attrs) { super(context, attrs); init(); setup(); } private void init() { // The majority of the magic happens here setPageTransformer(true, new VerticalPageTransformer()); // The easiest way to get rid of the overscroll drawing that happens on the left and right setOverScrollMode(OVER_SCROLL_NEVER); } private MotionEvent swapXY(MotionEvent ev) { float width = getWidth(); float height = getHeight(); float newX = (ev.getY() / height) * width; float newY = (ev.getX() / width) * height; ev.setLocation(newX, newY); return ev; } @Override public boolean onInterceptTouchEvent(MotionEvent ev){ boolean intercepted = super.onInterceptTouchEvent(swapXY(ev)); swapXY(ev); // return touch coordinates to original reference frame for any child views return intercepted; } private float scaleY ; @Override public boolean onTouchEvent(MotionEvent ev) { System.out.println("----------getY" + ev.getY()); System.out.println("----------scaleY" + scaleY); if (ev.getAction()==MotionEvent.ACTION_MOVE){ } if (ev.getAction()==MotionEvent.ACTION_DOWN){ scaleY = ev.getY(); } if (ev.getAction()==MotionEvent.ACTION_UP){ if (scaleY == ev.getY()){ System.out.println("------------------======"); scaleY= 0; return false; } } try { return super.onTouchEvent(swapXY(ev)); }catch (Exception e){ } return true; } public void setOnItemClickListener(OnItemClickListener onItemClickListener) { mOnItemClickListener = onItemClickListener; } public interface OnItemClickListener { void onItemClick(int position); } private void setup() { final GestureDetector tapGestureDetector = new GestureDetector(getContext(), new TapGestureListener()); setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { tapGestureDetector.onTouchEvent(event); return false; } }); } private class TapGestureListener extends GestureDetector.SimpleOnGestureListener { @Override public boolean onSingleTapConfirmed(MotionEvent e) { if(mOnItemClickListener != null) { mOnItemClickListener.onItemClick(getCurrentItem()); } return true; } }}要實(shí)現(xiàn)動畫效果的核心就在 setPageTransformer(true, new VerticalPageTransformer());，大家都知道這個是設(shè)置Viewpager 設(shè)置動畫的方法 ，那么要實(shí)現(xiàn)這個如果用系統(tǒng)自帶的切換動畫效果的話 肯定是不符合Viewpager 豎屏滑動的效果的。所以自定義PageTransformer 就是必然的趨勢了
private class VerticalPageTransformer implements ViewPager.PageTransformer { private float MIN_SCALE = 0.5f; @Override public void transformPage(View view, float position) { if (position < -1) { // [-Infinity,-1) // This page is way off-screen to the left. view.setAlpha(0); }else if (position <= 0) { // [-1,1] view.setAlpha(1 + position); view.setTranslationX(-view.getWidth() * position); view.setPivotY( view.getMeasuredHeight()); view.setPivotX( view.getMeasuredWidth()/2); view.setTranslationY( position * view.getHeight()); float scaleFactor = MIN_SCALE + (1 - MIN_SCALE) * (1 - Math.abs(position)); view.setScaleX(scaleFactor); view.setScaleY(scaleFactor); } else if (position <= 1) { // [-1,1] view.setAlpha(1); view.setTranslationX(-view.getWidth() * position); view.setTranslationY( position * view.getHeight()); float scaleFactor = MIN_SCALE + (1 - MIN_SCALE) * (1 - Math.abs(position)); } else { // (1,+Infinity] view.setAlpha(0); view.setTranslationY( position * view.getHeight()); } } }重寫transformPage 方法。然后得到如上gif 向左旋轉(zhuǎn)90的效果，剩下的代碼你們看看也就知道是item點(diǎn)擊事件與滑動事件的監(jiān)聽。所以就不細(xì)講了
以上就是本文的全部內(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持武林網(wǎng)。
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