ViewPagerCards

使用步骤:

第一步:初始化ViewPager:

<android.support.v4.view.ViewPager
 android:id="@+id/viewPager"
 android:layout_width="match_parent"
 android:layout_height="330dp"
 android:layout_gravity="bottom"
 android:clipToPadding="false"
 android:overScrollMode="never"
 android:paddingBottom="30dp"
 android:paddingEnd="@dimen/card_padding"
 android:paddingLeft="@dimen/card_padding"
 android:paddingRight="@dimen/card_padding"
 android:paddingStart="@dimen/card_padding" />

第二步:设置setPageTransformer:

public class ShadowTransformer implements ViewPager.OnPageChangeListener, ViewPager.PageTransformer {
 private ViewPager mViewPager;
 private CardAdapter mAdapter;
 private float mLastOffset;
 private boolean mScalingEnabled;
 public ShadowTransformer(ViewPager viewPager, CardAdapter adapter) {
 mViewPager = viewPager;
 viewPager.addOnPageChangeListener(this);
 mAdapter = adapter;
 }
 public void enableScaling(boolean enable) {
 if (mScalingEnabled && !enable) {
 // shrink main card
 CardView currentCard = mAdapter.getCardViewAt(mViewPager.getCurrentItem());
 if (currentCard != null) {
 currentCard.animate().scaleY(1);
 currentCard.animate().scaleX(1);
 }
 }else if(!mScalingEnabled && enable){
 // grow main card
 CardView currentCard = mAdapter.getCardViewAt(mViewPager.getCurrentItem());
 if (currentCard != null) {
 currentCard.animate().scaleY(1.1f);
 currentCard.animate().scaleX(1.1f);
 }
 }
 mScalingEnabled = enable;
 }
 @Override
 public void transformPage(View page, float position) {
 }
 @Override
 public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
 int realCurrentPosition;
 int nextPosition;
 float baseElevation = mAdapter.getBaseElevation();
 float realOffset;
 boolean goingLeft = mLastOffset > positionOffset;
 // If we're going backwards, onPageScrolled receives the last position
 // instead of the current one
 if (goingLeft) {
 realCurrentPosition = position + 1;
 nextPosition = position;
 realOffset = 1 - positionOffset;
 } else {
 nextPosition = position + 1;
 realCurrentPosition = position;
 realOffset = positionOffset;
 }
 // Avoid crash on overscroll
 if (nextPosition > mAdapter.getCount() - 1
 || realCurrentPosition > mAdapter.getCount() - 1) {
 return;
 }
 CardView currentCard = mAdapter.getCardViewAt(realCurrentPosition);
 // This might be null if a fragment is being used
 // and the views weren't created yet
 if (currentCard != null) {
 if (mScalingEnabled) {
 currentCard.setScaleX((float) (1 + 0.1 * (1 - realOffset)));
 currentCard.setScaleY((float) (1 + 0.1 * (1 - realOffset)));
 }
 currentCard.setCardElevation((baseElevation + baseElevation
 * (CardAdapter.MAX_ELEVATION_FACTOR - 1) * (1 - realOffset)));
 }
 CardView nextCard = mAdapter.getCardViewAt(nextPosition);
 // We might be scrolling fast enough so that the next (or previous) card
 // was already destroyed or a fragment might not have been created yet
 if (nextCard != null) {
 if (mScalingEnabled) {
 nextCard.setScaleX((float) (1 + 0.1 * (realOffset)));
 nextCard.setScaleY((float) (1 + 0.1 * (realOffset)));
 }
 nextCard.setCardElevation((baseElevation + baseElevation
 * (CardAdapter.MAX_ELEVATION_FACTOR - 1) * (realOffset)));
 }
 mLastOffset = positionOffset;
 }
 @Override
 public void onPageSelected(int position) {
 }
 @Override
 public void onPageScrollStateChanged(int state) {
 }
}

第三步:设置setAdapter:

public class CardFragmentPagerAdapter extends FragmentStatePagerAdapter implements CardAdapter {
 private List<CardFragment> mFragments;
 private float mBaseElevation;
 public CardFragmentPagerAdapter(FragmentManager fm, float baseElevation) {
 super(fm);
 mFragments = new ArrayList<>();
 mBaseElevation = baseElevation;
 for(int i = 0; i< 5; i++){
 addCardFragment(new CardFragment());
 }
 }
 @Override
 public float getBaseElevation() {
 return mBaseElevation;
 }
 @Override
 public CardView getCardViewAt(int position) {
 return mFragments.get(position).getCardView();
 }
 @Override
 public int getCount() {
 return mFragments.size();
 }
 @Override
 public Fragment getItem(int position) {
 return mFragments.get(position);
 }
 @Override
 public Object instantiateItem(ViewGroup container, int position) {
 Object fragment = super.instantiateItem(container, position);
 mFragments.set(position, (CardFragment) fragment);
 return fragment;
 }
 public void addCardFragment(CardFragment fragment) {
 mFragments.add(fragment);
 }
}

第四步:设置CardAdapter:

public interface CardAdapter {
 int MAX_ELEVATION_FACTOR = 8;
 float getBaseElevation();
 CardView getCardViewAt(int position);
 int getCount();
}

第五步:实现:

mViewPager.setAdapter(mFragmentCardAdapter);
mViewPager.setPageTransformer(false, mFragmentCardShadowTransformer);