摘要：
mIsTouching&&getAdapter（）！=null&&getAdapter（）。getCount（）˃1）｛post（newRunnable（）｛@Overridepublicvoidrun（）{setCurrentItem（getCurrentItem（）+1）；｝｝）；｝打破case暂停：中断；caseDESTROY:shutdownTimer（）；break；}}}，01000*超时，时间单位。毫秒）；}publicvoisetHasData（booleanhasData）｛this.hasData=hasData；｝publicvoidsetTimeOut（inttimeOut）｛this.timeOut=timeOut；｝@OverrideprotectedvoidonDetachedFromWindow（）｛super.onDetachedfrom Window（）；shutdownTimer（）；｝privatevoidshutdownTimer（）｛if（mCarouselTimer！
1、轮播控件涉及到的两个类
CarouselViewPager.javapublic class CarouselViewPager extends ViewPager { @IntDef({RESUME, PAUSE, DESTROY}) @Retention(RetentionPolicy.SOURCE) public @interface LifeCycle { } public static final int RESUME = 0; public static final int PAUSE = 1; public static final int DESTROY = 2; /** * 生命周期状态，保证{@link #mCarouselTimer}在各生命周期选择执行策略 */ private int mLifeCycle = RESUME; /** * 是否正在触摸状态，用以防止触摸滑动和自动轮播冲突 */ private boolean mIsTouching = false; /** * 超时时间 */ private int timeOut = 2; /** * 轮播定时器 */ private ScheduledExecutorService mCarouselTimer; /** * 有数据时，才开始进行轮播 */ private boolean hasData; public CarouselViewPager(Context context) { super(context); } public CarouselViewPager(Context context, AttributeSet attrs) { super(context, attrs); } public void setLifeCycle(@LifeCycle int lifeCycle) { this.mLifeCycle = lifeCycle; } @Override public boolean onTouchEvent(MotionEvent ev) { switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: case MotionEvent.ACTION_MOVE: mIsTouching = true; break; case MotionEvent.ACTION_CANCEL: case MotionEvent.ACTION_UP: mIsTouching = false; break; } return super.onTouchEvent(ev); } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); startTimer(); } public void startTimer() { if (!hasData) { return; } shutdownTimer(); mCarouselTimer = Executors.newSingleThreadScheduledExecutor(); mCarouselTimer.scheduleAtFixedRate(new Runnable() { @Override public void run() { switch (mLifeCycle) { case RESUME: if (!mIsTouching && getAdapter() != null && getAdapter().getCount() > 1) { post(new Runnable() { @Override public void run() { setCurrentItem(getCurrentItem() + 1); } }); } break; case PAUSE: break; case DESTROY: shutdownTimer(); break; } } }, 0, 1000 * timeOut, TimeUnit.MILLISECONDS); } public void setHasData(boolean hasData) { this.hasData = hasData; } public void setTimeOut(int timeOut) { this.timeOut = timeOut; } @Override protected void onDetachedFromWindow() { super.onDetachedFromWindow(); shutdownTimer(); } private void shutdownTimer() { if (mCarouselTimer != null && mCarouselTimer.isShutdown() == false) { mCarouselTimer.shutdown(); } mCarouselTimer = null; } }
CarouselPagerAdapter.java/** * @描述 @link CarouselViewPager 轮播控件}所需的adapter */ public abstract class CarouselPagerAdapter<V extends CarouselViewPager> extends PagerAdapter { /** * 系数，可以自行设置，但又以下原则需要遵循： * <ul> * <li>必须大于1</li> * <li>尽量小</li> * </ul> */ private static final int COEFFICIENT = 10; private V mViewPager; public CarouselPagerAdapter(V viewPager) { this.mViewPager = viewPager; } /** * @return 实际数据数量 */ @IntRange(from = 0) public abstract int getRealDataCount(); @Override public final int getCount() { long realDataCount = getRealDataCount(); if (realDataCount > 1) { realDataCount = getRealDataCount() * COEFFICIENT; realDataCount = realDataCount > Integer.MAX_VALUE ? Integer.MAX_VALUE : realDataCount; } return (int) realDataCount; } @Override public final boolean isViewFromObject(View view, Object object) { return view == object; } @Override public final Object instantiateItem(ViewGroup container, int position) { position = position % getRealDataCount(); return this.instantiateRealItem(container, position); } public abstract Object instantiateRealItem(ViewGroup container, int position); @Override public final void destroyItem(ViewGroup container, int position, Object object) { container.removeView((View) object); } @Override public final void finishUpdate(ViewGroup container) { // 数量为1，不做position替换 if (getCount() <= 1) { return; } int position = mViewPager.getCurrentItem(); // ViewPager的更新即将完成，替换position，以达到无限循环的效果 if (position == 0) { position = getRealDataCount(); mViewPager.setCurrentItem(position, false); } else if (position == getCount() - 1) { position = getRealDataCount() - 1; mViewPager.setCurrentItem(position, false); } } }
2、实现3D效果需要用到的类
public class GalleryTransformer implements ViewPager.PageTransformer { @Override public void transformPage(View view, float position) { float scale = 0.5f; float scaleValue = 1 - Math.abs(position) * scale; view.setScaleX(scaleValue); view.setScaleY(scaleValue); view.setAlpha(scaleValue); view.setPivotX(view.getWidth() * (1 - position - (position > 0 ? 1 : -1) * 0.75f) * scale); view.setElevation(position > -0.25 && position < 0.25 ? 1 : 0); } }
3、使用方法
public class MainActivity extends AppCompatActivity { private CarouselViewPager viewPager; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); viewPager = (CarouselViewPager) findViewById(R.id.id_viewpager); ImagePagerAdapter adapter = new ImagePagerAdapter(this, viewPager); viewPager.setOffscreenPageLimit(3); viewPager.setAdapter(adapter); // 设置轮播时间 viewPager.setTimeOut(5); // 设置3d效果 viewPager.setPageTransformer(true, new GalleryTransformer()); // 设置已经有数据了，可以进行轮播，一般轮播的图片等数据是来源于网络，网络数据来了后才设置此值，此处因为是demo，所以直接赋值了 viewPager.setHasData(true); // 开启轮播 viewPager.startTimer(); } }
public class ImagePagerAdapter extends CarouselPagerAdapter<CarouselViewPager> { public ImagePagerAdapter(Context context, CarouselViewPager viewPager) { super(viewPager); } int[] imgRes = { R.drawable.img_wallhaven_426244, R.drawable.img_wallhaven_431231, R.drawable.img_wallhaven_432740, /* R.drawable.img_wallhaven_426244, R.drawable.img_wallhaven_431231, R.drawable.img_wallhaven_432740, R.drawable.img_wallhaven_426244, R.drawable.img_wallhaven_431231, R.drawable.img_wallhaven_432740,*/ }; @Override public Object instantiateRealItem(ViewGroup container, int position) { ImageView view = new ImageView(container.getContext()); view.setScaleType(ImageView.ScaleType.FIT_XY); view.setAdjustViewBounds(true); view.setImageResource(imgRes[position]); view.setLayoutParams(new LinearLayout.LayoutParams(900, 400)); container.addView(view); return view; } @Override public int getRealDataCount() { return imgRes != null ? imgRes.length : 0; } }
ps:
ImagePagerAdapter.java是一个普通的PagerAdapter类，用户自定义，需要继承CarouselPagerAdapter<CarouselViewPager>并重写CarouselPagerAdapter的构造方法，在
public Object instantiateRealItem(ViewGroup container, int position) 方法中定义界面的具体显示 public int getRealDataCount() {
return imgRes != null ? imgRes.length : 0;
}方法中返回具体的页面总数<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:clipChildren="false" android:gravity="center" tools:context=".MainActivity"> <com.twiceyuan.galleryviewpager.CarouselViewPager android:id="@+id/id_viewpager" android:layout_width="240dp" android:layout_height="120dp" android:clipChildren="false"/> </RelativeLayout>
