如何在ViewPager上进行循环滚动？

Question

我想将我的ViewPager设置为循环滚动。我希望第一页能够滚动到第2页和最后一页。我希望我的最后一页滚动到[最后一页-1]和第一页。我已经尝试了，虽然我不确定何时调用我创建的方法。在ViewPager中似乎没有一种方法可以处理这种事情，所以我创建了下面的内容。

    public ViewPagerAdapter(final ViewPager pager, int... pageIDs) {
        super();
        int actualNoOfIDs = pageIDs.length;
        count = actualNoOfIDs + 2;
        Log.d(TAG, "actualNoOfIDs: " + actualNoOfIDs +
                "count: " + count);

        pageIDsArray = new int[count];
        for (int i = 0; i < actualNoOfIDs; i++) {
            pageIDsArray[ i + 1] = pageIDs[i];
        }
        pageIDsArray[0] = pageIDs[actualNoOfIDs - 1];
        pageIDsArray[count - 1] = pageIDs[0];

        Log.d(TAG, "actualNoOfIDs#2: " + actualNoOfIDs +
                "count#2: " + count);
        pager.setOnPageChangeListener(new OnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                int pageCount = getCount();
                if (position == 0) {
                    pager.setCurrentItem(pageCount - 2, false);
                } else if (position == pageCount - 1) {
                    pager.setCurrentItem(1, false);
                }
            }

            @Override
            public void onPageScrollStateChanged(int state) {
                // TODO Auto-generated method stub
                Log.d(TAG, "onPageScrollStateChanged()");
//              if (state == ViewPager.SCROLL_STATE_IDLE) { 
//                  int pageCount = getCount(); 
//                  int currentItem = pager.getCurrentItem(); 
//                  if (currentItem == 0) { 
//                      pager.setCurrentItem(pageCount - 2, false); 
//                  } else if (currentItem == pageCount - 1) { 
//                      pager.setCurrentItem(1, false); 
//                  } 
//              } 

            }

            @Override
            public void onPageScrolled(int position, float positionOffset, 
                    int positionOffsetPixels) {
                // TODO Auto-generated method stub
                Log.d(TAG, "onPageScrolled()");

            }
        });
    }

我的整个代码有点冗长，但如果有帮助我可以发布它。

public class ViewPagerAdapter extends PagerAdapter {
    public static String TAG = ViewPagerAdapter.class.getSimpleName();

    private int count;
    private int[] pageIDsArray;

    private TextToSpeech btnTTS;
    private TtsButton tTSBtn;

    String inputTxt;
    Context context;
    View itemView;

    TextView tvNumber; // container for atomic number
    TextView tvSymbol; // container for symbol
    TextView tvWeight; // container for weight
    TextView tvName; // container for name
    TextView tvGroup; // container for group
    TextView tvPeriod; // container for period
    TextView tvBlock; // container for block
    TextView tvFamily; // container for family
    TextView tvColor; // container for color
    TextView tvPhase; // container for phase
    TextView tvMelt; // container for melting point
    TextView tvBoil; // container for boiling point
    TextView tvNeutrons; // container for neutrons
    TextView tvProtons; // container for protons
    TextView tvElectrons; // container for electrons
    TextView tvUrl; // container for electrons

    public ViewPagerAdapter(Context context, List<Integer> arrayAtomicNum, 
            List<String> arrayName, List<String> arraySymbol, List<String> arrayFamily,
            List<String> arrayPhase, List<String> arrayColor, List<Integer> arrayGroup, 
            List<Integer> arrayPeriod, List<String> arrayBlock, List<Integer> arrayProtons,
            List<Integer> arrayNeutrons, List<Integer> arrayElectrons, List<Double> arrayWeight,
            List<Double> arrayMelt, List<Double> arrayBoil, List<String> arrayUrl) {    
        this.context = context;
        ElementStructure.arrayAtomicNum = arrayAtomicNum;
        ElementStructure.arrayName = arrayName;
        ElementStructure.arraySymbol = arraySymbol;
        ElementStructure.arrayFamily = arrayFamily;
        ElementStructure.arrayPhase = arrayPhase;
        ElementStructure.arrayColor = arrayColor;
        ElementStructure.arrayGroup = arrayGroup;
        ElementStructure.arrayPeriod = arrayPeriod;
        ElementStructure.arrayBlock = arrayBlock;
        ElementStructure.arrayProtons = arrayProtons;
        ElementStructure.arrayNeutrons = arrayNeutrons;
        ElementStructure.arrayElectrons = arrayElectrons;
        ElementStructure.arrayWeight = arrayWeight;
        ElementStructure.arrayMelt = arrayMelt;
        ElementStructure.arrayBoil = arrayBoil;
        ElementStructure.arrayUrl = arrayUrl;
    }


    public ViewPagerAdapter(final ViewPager pager, int... pageIDs) {
        super();
        int actualNoOfIDs = pageIDs.length;
        count = actualNoOfIDs + 2;
        Log.d(TAG, "actualNoOfIDs: " + actualNoOfIDs +
                "count: " + count);

        pageIDsArray = new int[count];
        for (int i = 0; i < actualNoOfIDs; i++) {
            pageIDsArray[ i + 1] = pageIDs[i];
        }
        pageIDsArray[0] = pageIDs[actualNoOfIDs - 1];
        pageIDsArray[count - 1] = pageIDs[0];

        Log.d(TAG, "actualNoOfIDs#2: " + actualNoOfIDs +
                "count#2: " + count);
        pager.setOnPageChangeListener(new OnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                int pageCount = getCount();
                if (position == 0) {
                    pager.setCurrentItem(pageCount - 2, false);
                } else if (position == pageCount - 1) {
                    pager.setCurrentItem(1, false);
                }
            }

            @Override
            public void onPageScrollStateChanged(int state) {
                // TODO Auto-generated method stub
                Log.d(TAG, "onPageScrollStateChanged()");
//              if (state == ViewPager.SCROLL_STATE_IDLE) { 
//                  int pageCount = getCount(); 
//                  int currentItem = pager.getCurrentItem(); 
//                  if (currentItem == 0) { 
//                      pager.setCurrentItem(pageCount - 2, false); 
//                  } else if (currentItem == pageCount - 1) { 
//                      pager.setCurrentItem(1, false); 
//                  } 
//              } 

            }

            @Override
            public void onPageScrolled(int position, float positionOffset, 
                    int positionOffsetPixels) {
                // TODO Auto-generated method stub
                Log.d(TAG, "onPageScrolled()");

            }
        });
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return ElementStructure.arrayAtomicNum.size();

    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        // TODO Auto-generated method stub
        return view == ((RelativeLayout) object);
    }

    @Override
    public Object instantiateItem(ViewGroup container, final int position) {

        LayoutInflater inflater = (LayoutInflater) context
             .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        int layoutColorId = ElementStructure.arrayLayoutColor.get(position);

        if (layoutColorId == 1) {
            itemView = inflater.inflate(R.layout.frame_learn_a, container,
                     false);
        } else if (layoutColorId == 2) {
            itemView = inflater.inflate(R.layout.frame_learn_b, container,
                     false);
        } else if (layoutColorId == 3) {
            itemView = inflater.inflate(R.layout.frame_learn_c, container,
                     false);
        } else if (layoutColorId == 4) {
            itemView = inflater.inflate(R.layout.frame_learn_d, container,
                     false);    
        }

        Button btnSpeak = (Button)itemView.findViewById(R.id.btnaudio);

        btnSpeak.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                inputTxt = ElementStructure.arrayName.get(position);
                tTSBtn = new TtsButton(this, inputTxt); 
            }

        });

        // atomic number textView
        tvNumber = (TextView)itemView.findViewById(R.id.metanumber);

        // symbol textView
        tvSymbol = (TextView)itemView.findViewById(R.id.metasymbol);

        // weight textView
        tvWeight = (TextView)itemView.findViewById(R.id.metaweight);

        // name textView
        tvName = (TextView)itemView.findViewById(R.id.metaname);

        // group textView
        tvGroup = (TextView)itemView.findViewById(R.id.metagroup);

        // period textView
        tvPeriod = (TextView)itemView.findViewById(R.id.metaperiod);

        // block textView
        tvBlock = (TextView)itemView.findViewById(R.id.metablock);

        // family textView
        tvFamily = (TextView)itemView.findViewById(R.id.metafamily);

        // color textView
        tvColor = (TextView)itemView.findViewById(R.id.metacolor);

        // phase textView
        tvPhase = (TextView)itemView.findViewById(R.id.metaphase);

        // melting point textView
        tvMelt = (TextView)itemView.findViewById(R.id.metamelt);

        // boiling point textView
        tvBoil = (TextView)itemView.findViewById(R.id.metaboil);

        // neutrons textView
        tvNeutrons = (TextView)itemView.findViewById(R.id.metaneutrons);

        // protons textView
        tvProtons = (TextView)itemView.findViewById(R.id.metaprotons);

        // electrons textView
        tvElectrons = (TextView)itemView.findViewById(R.id.metaelectrons);

        // url textView
        tvUrl = (TextView)itemView.findViewById(R.id.metaurl);

        // capture position and set to the TextViews
        tvNumber.setText(String.valueOf(ElementStructure.arrayAtomicNum.get(position)));
        tvSymbol.setText(ElementStructure.arraySymbol.get(position));
        tvWeight.setText(String.valueOf(ElementStructure.arrayWeight.get(position)));
        tvName.setText(ElementStructure.arrayName.get(position));
        tvPeriod.setText(String.valueOf(ElementStructure.arrayPeriod.get(position)));
        tvBlock.setText(String.valueOf(ElementStructure.arrayBlock.get(position)));
        tvFamily.setText(ElementStructure.arrayFamily.get(position));
        tvColor.setText(ElementStructure.arrayColor.get(position));
        tvPhase.setText(ElementStructure.arrayPhase.get(position));
        tvNeutrons.setText(String.valueOf(ElementStructure.arrayNeutrons.get(position)));
        tvProtons.setText(String.valueOf(ElementStructure.arrayProtons.get(position)));
        tvElectrons.setText(String.valueOf(ElementStructure.arrayElectrons.get(position)));
        tvUrl.setText(ElementStructure.arrayUrl.get(position));

        // capture position, adjust for 0 value cases
        if (ElementStructure.arrayGroup.get(position) == 0) {
            tvGroup.setText("n/a");
        } else {
            tvGroup.setText(String.valueOf(ElementStructure.arrayGroup.get(position)));
        }

        if (ElementStructure.arrayMelt.get(position) == 0) {
            tvMelt.setText("n/a");
        } else {
            tvMelt.setText(String.valueOf(ElementStructure.arrayMelt.get(position)));
        }

        if (ElementStructure.arrayBoil.get(position) == 0) {
            tvBoil.setText("n/a");
        } else {
            tvBoil.setText(String.valueOf(ElementStructure.arrayBoil.get(position)));
        }

        // add fragments to container (ViewPager)
        ((ViewPager) container).addView(itemView);
        return itemView;

    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        Log.d(TAG, "destroyItem()");
        // remove fragments from container (ViewPager)
        ((ViewPager) container).removeView((RelativeLayout) object);
    }


    @Override
    public void finishUpdate(View container) {
        // TODO Auto-generated method stub
        Log.d(TAG, "finishUpdate()");
    }

    @Override
    public void restoreState(Parcelable state, ClassLoader loader) {
        // TODO Auto-generated method stub
        Log.d(TAG, "restoreState()");
    }

    @Override
    public Parcelable saveState() {
        // TODO Auto-generated method stub
        Log.d(TAG, "saveState()");
        return null;
    }

    @Override
    public void startUpdate(View container) {
        // TODO Auto-generated method stub
        Log.d(TAG, "startUpdate()");
    }




    public class TtsButton extends Activity implements OnInitListener {

        public TtsButton(OnClickListener onClickListener, String inputTxt) {
            super();
            tTSCheck(inputTxt);
        }

        private void tTSCheck (String inputTxt) {

            int resultCodeCheck = TextToSpeech.Engine.CHECK_VOICE_DATA_PASS;
            if (resultCodeCheck == 1) {
                btnTTS = new TextToSpeech(context, this);
            } else {
                Intent installTTSFiles = new Intent(); //missing data, install it
                installTTSFiles.setAction(TextToSpeech.Engine.ACTION_INSTALL_TTS_DATA);
                startActivity(installTTSFiles);
            }
        }

        @Override
        public void onInit(int status) {
            // TODO Auto-generated method stub
            if(status == TextToSpeech.SUCCESS)
            {
                Log.i(TAG, "TTS INIT: SUCCESS");
                btnTTS.setLanguage(Locale.US);
                btnTTS.speak(inputTxt, TextToSpeech.QUEUE_FLUSH, null);
            }
            else if(status == TextToSpeech.ERROR)
            {
                Log.e(TAG, "TTS INIT: ERROR");
            }
        }

        @Override
        public void onPause() {
            if (btnTTS != null) {
                btnTTS.stop();
                btnTTS.shutdown();
            }
            super.onPause();
        }

    } //end embedded class

} //end ViewPagerAdapter

提前致谢。我正在考虑尝试使用动作手势，但是，我真的不明白为什么我的方法不能工作这么久以至于我可以在正确的位置调用它。我最初的想法是每次位置改变时调用它在“Object instantiateItem（ViewGroup容器，最终的int位置）”，如果条件是正确的。但我不确定这是不是最好。

Answer 1

这是一个没有虚假页面的解决方案，就像魅力一样：

public class CircularViewPagerHandler implements ViewPager.OnPageChangeListener {
    private ViewPager   mViewPager;
    private int         mCurrentPosition;
    private int         mScrollState;

    public CircularViewPagerHandler(final ViewPager viewPager) {
        mViewPager = viewPager;
    }

    @Override
    public void onPageSelected(final int position) {
        mCurrentPosition = position;
    }

    @Override
    public void onPageScrollStateChanged(final int state) {
        handleScrollState(state);
        mScrollState = state;
    }

    private void handleScrollState(final int state) {
        if (state == ViewPager.SCROLL_STATE_IDLE) {
            setNextItemIfNeeded();
        }
    }

    private void setNextItemIfNeeded() {
        if (!isScrollStateSettling()) {
            handleSetNextItem();
        }
    }

    private boolean isScrollStateSettling() {
        return mScrollState == ViewPager.SCROLL_STATE_SETTLING;
    }

    private void handleSetNextItem() {
        final int lastPosition = mViewPager.getAdapter().getCount() - 1;
        if(mCurrentPosition == 0) {
            mViewPager.setCurrentItem(lastPosition, false);
        } else if(mCurrentPosition == lastPosition) {
            mViewPager.setCurrentItem(0, false);
        }
    }

    @Override
    public void onPageScrolled(final int position, final float positionOffset, final int positionOffsetPixels) {
    }
}

你只需要将它作为onPageChangeListener设置为你的ViewPager，就是这样：

viewPager.setOnPageChangeListener(new CircularViewPagerHandler(viewPager));

为避免在ViewPager的“结尾”出现这种蓝色光芒，您应该将此行应用于放置ViewPager的xml：

android:overScrollMode="never"

Answer 2

好的，我有一个答案。它实际上比我想象的要容易，但确实需要一些技巧。首先，让我从设置开始。可以说，例如，您在ViewPager中滚动浏览了三个页面（A-B-C）。并且你想要设置它，这样如果你继续滚动C（第3页），它会转到A（第1页），如果你在A（第1页）上向后滚动它会转到C（第3页） ）。

我不是说我的解决方案是最好的，但它有效，我没有看到任何问题。首先，您必须创建两个“假”页面。虚假页面代表ViewPager的第一页和最后一页。接下来你需要设置一个onPageChangeListener（），并使用onPageSelected（）方法。您需要假页面的原因是因为onPageSelected（）仅在您移动（滑动）后注册。换句话说，如果没有这种方法，最终用户将不得不滚动到第2页并返回第1页以接收第1页上的匹配，这也意味着将跳过第1页，具体取决于您的代码逻辑。

设置确实是完整的答案。一旦你有假页面，只需在必要的方法中使用setCurrentItem（）。

以下是我的代码的外观。确保将它放在公共Object instantiateItem（最终的ViewGroup容器，最终的int position）方法中，就在您将容器中的视图返回之前。

((ViewPager) container).setOnPageChangeListener(new OnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                Log.d(TAG, "onPageSelected() :: " + "position: " + position);

                // skip fake page (first), go to last page
                if (position == 0) {
                    ((ViewPager) container).setCurrentItem(118, false);
                }

                // skip fake page (last), go to first page
                if (position == 119) {
                    ((ViewPager) container).setCurrentItem(1, false); //notice how this jumps to position 1, and not position 0. Position 0 is the fake page!
                }

            }

就是这样，它就是诀窍！唯一要做的就是在第1位开始你的ViewPager（这是第二页：假页=第1页，我的真实起始页=第2页）。现在，每次滚动到假页面时，我都会将其重定向到最后一个真实页面。每次我向前滚动到最后一个假页面时，我都会将其重定向到真正的起始页面（第2页）。

另外，不要尝试在onPageScrollStateChanged中放入任何代码。这种方法很奇怪，似乎状态值是无法控制的。它不断从一个州跳到另一个州。即使没有滚动。这只是我提到的一个提示。

Answer 3

我创建了圆形viewpager，在向左滑动期间从上到下顺畅滚动，在向右滑动时从第一个到最后一个。

为此添加了起始页和最后一页的最后一页： 在addOnPageChangeListener里面：我们要做一些计算，当我们在0位置然后在onPageScrollStateChanged上设置当前项目作为最后一项，反之亦然。

查看代码

public class ViewPagerCircular_new extends AppCompatActivity {
ViewPager viewPager;
ArrayList<String> str = new ArrayList<String>();
boolean chageImage = false;
int setPos;

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.view_pager_normal);
    viewPager = (ViewPager) findViewById(R.id.vf_home_top_pager);
    str.add("6");         // added the last page to the frist
    str.add("1");        // First item to display in view pager
    str.add("2");
    str.add("3");
    str.add("4");
    str.add("5");
    str.add("6");     // last item to display in view pager
    str.add("1");      // added the first page to the last
    ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
    viewPager.setAdapter(adapter);
    viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener()
    {

        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels)
        {
            if (position == str.size() - 1)
            {
                chageImage = true;
                setPos = 1;
            } else if (position == 0)
            {
                chageImage = true;
                setPos = str.size() - 2;
            } else
            {
                chageImage = false;
            }
        }

        @Override
        public void onPageSelected(int position)
        {
        }

        @Override
        public void onPageScrollStateChanged(int state)
        {
            if (state == ViewPager.SCROLL_STATE_IDLE && chageImage)
            {
                viewPager.setCurrentItem(setPos, false);
            }
        }
    });
// display the 1st item as current item 
    viewPager.setCurrentItem(1);
}

//寻呼机适配器

public class ViewPagerAdapter extends FragmentStatePagerAdapter
{

    public ViewPagerAdapter(FragmentManager fm)
    {
        super(fm);
    }

    @Override
    public Fragment getItem(int position)
    {
        PagerFragment fragment = new PagerFragment();
        Bundle bundle = new Bundle();
        bundle.putString("pos", str.get(position));
        fragment.setArguments(bundle);
        return fragment;
    }

    @Override
    public int getCount()
    {
        return str.size();
    }

}

//要在适配器中显示的片段

public class PagerFragment extends Fragment
{

    Bundle bundle;
    String pos;

    public PagerFragment()
    {
    }

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        bundle = getArguments();
        pos = bundle.getString("pos");
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        TextView textView = new TextView(ViewPagerCircular_new.this);
        textView.setGravity(Gravity.CENTER);
        textView.setTextSize(25);
        textView.setText(pos);
        return textView;
    }

}

}

Answer 4

试试这个

((ViewPager) container)
                .setOnPageChangeListener(new OnPageChangeListener() {
                    @Override
                    public void onPageSelected(int position) {
                        Log.i("TAG", "pos::" + position);

                    }
                    @Override
                    public void onPageScrollStateChanged(int state) {
                        // TODO Auto-generated method stub                            
                           int currentPage = pager.getCurrentItem();
                           Log.i("TAG", "currentPage::" + currentPage);
                           Log.i("TAG", "currentState::" + currentState);
                           Log.i("TAG", "previousState::" + previousState);
                           if (currentPage == 4 || currentPage == 0) {
                            previousState = currentState;
                            currentState = state;
                            if (previousState == 1 && currentState == 0) {
                             pager.setCurrentItem(currentPage == 0 ? 4 : 0);
                            }
                           }

                    }

                    @Override
                    public void onPageScrolled(int arg0, float arg1,
                            int arg2) {
                        // TODO Auto-generated method stub

                    }
                });

        return

这应该放在

里面

 @Override
    public Object instantiateItem(final View container, int position) {}

Answer 5

我稍微修改了@portfoliobuilder的答案。这很简单。 设置当前项目时没有平滑滚动，直到PageChangeState为“0”，因此它会非常流畅。

((ViewPager)container).setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

    }

    @Override
    public void onPageSelected(int position) {
        currentPage = position;
    }

    @Override
    public void onPageScrollStateChanged(int state) {

        // state equals to 0 means the scroll action is stop
        if(state == 0) {

            if(currentPage == 0)
                ((ViewPager)container).setCurrentItem(imageResourceList.size()-2,false);

            if(currentPage == imageResourceList.size()-1)
                ((ViewPager)container).setCurrentItem(1,false);
        }
    }
});

Answer 6

这是我的解决方案：

myViewPager.java

public class myViewPager extends PagerAdapter {

    public myViewPager (Context context) {
        this.context = context;
    }

    @Override
    public int getCount() {
        return rank.length+2;
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == object;
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        // Declare Variables

        TextView textViewRank;



        //Log.i(TAG, "get position = "+position);

        inflater = (LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View itemView = inflater.inflate(R.layout.viewpager_item, container,
            false);

        textViewRank= (TextView) itemView.findViewById(R.id.textView1);

        if (position == getCount() - 1) {
            textViewRank.setText(rank[0]);
        } else if (position == 0) {
            textViewRank.setText(rank[rank.length-1]);
        } else {
            textViewRank.setText(rank[position-1]);
        }


        ((ViewPager) container).addView(itemView);

        return itemView;
    }
    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        container.removeView((View) object);
    }
}

viewpager_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:id="@+id/textView1"/>
</LinearLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {
    private static final String TAG = MainActivity.class.getName();
    public static String[] rank;
    myViewPager adapter;
    private ViewPager viewPager;
    private static int currentPage;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        rank = new String[] { "1", "2", "3", "4", "5", "6", "7", "8", "9", "10" };
        viewPager = (ViewPager) findViewById(R.id.view_pager);
        adapter = new myViewPager(this);

        viewPager.setAdapter(adapter);

        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                Log.i(TAG, "onPageSelected = "+position);
                currentPage = position;
            }
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
                // not needed
            }
            @Override
            public void onPageScrollStateChanged(int state) {
                if (state == ViewPager.SCROLL_STATE_IDLE) {
                    int pageCount = rank.length+2;

                    if (currentPage == pageCount-1){
                        viewPager.setCurrentItem(1,false);
                    } else if (currentPage == 0){
                        viewPager.setCurrentItem(pageCount-2,false);
                    }
                }
            }
        });
    }


}

activity_main.xml中

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1" />

</LinearLayout>

假设数组有10个元素。然后“添加”2个虚拟元素，但不是真的添加。当调用“get_count”函数时，只返回size = 10 + 2个元素。

虚拟e [0] e [1] e [2] e [3] e [4] e [5] e [6] e [7] e [8] e [9]虚拟

在viewPager.addOnPageChangeListener中：

当您滑动到最后一个元素时，viewPager应将第一个元素设置为下一个元素。

if (currentPage == pageCount-1){
    viewPager.setCurrentItem(1,false);
}

当您滑动到第一个元素时，viewPager应将最后一个元素设置为下一个元素。

else if (currentPage == 0){
    viewPager.setCurrentItem(pageCount-2,false);
}

在instantiateItem中：

 if (position == getCount() - 1) {
    textViewRank.setText(rank[0]);
 } else if (position == 0) {
    textViewRank.setText(rank[rank.length-1]);    
 } else {
    textViewRank.setText(rank[position-1]);
 }

Answer 7

我尝试了@ Portfoliobuilder的解决方案，这很棒。但是有一个小问题：当前项目是头部或尾部时，如果我只是单击ViewPager而不是拖动，则项目将变为尾部或头部。我在ViewPager中添加了一个触摸侦听器来解决问题。

skinPager.setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            //Record the x when press down and touch up, 
            //to judge whether to scroll between head and tail
            int x = (int) event.getX();
            int y = (int) event.getY();
            if(event.getAction() == MotionEvent.ACTION_DOWN)
                skinPagerPressX = x;
            else if(event.getAction() == MotionEvent.ACTION_UP)
                skinPagerUpX = x;
            return false;
        }
    });

以下是portfoliobuilder的修改功能：

private void handleSetNextItem() {
    final int lastPosition = skinPager.getAdapter().getCount() - 1;
    //Only scroll when dragged
    if(mCurrentPosition == 0 && skinPagerUpX > skinPagerPressX) {
        skinPager.setCurrentItem(lastPosition, false);
    } else if(mCurrentPosition == lastPosition && skinPagerUpX < skinPagerPressX) {
        skinPager.setCurrentItem(0, false);
    }
}

Answer 8

@tobi_b的答案并不完全成功，因为它从最后一次到第一次都没有顺利滑动（至少在我的试用中）。但我的答案真的让他感到鼓舞。 我的解决方案是什么时候从假的最后跳到真正的第一个，等到最后一个滚动完成。这是我的代码，很简单，

private final class MyPageChangeListener implements OnPageChangeListener {

    private int currentPosition;

    @Override
    public void onPageScrollStateChanged(int state) {
        if (state == ViewPager.SCROLL_STATE_IDLE) {
            if (currentPosition == viewPager.getAdapter().getCount() - 1) {
                viewPager.setCurrentItem(1, false);
            }
            else if (currentPosition == 0) {
                viewPager.setCurrentItem(viewPager.getAdapter().getCount() - 2, false);
            }
        }
    }

    @Override
    public void onPageScrolled(int scrolledPosition, float percent, int pixels) {
        //empty
    }

    @Override
    public void onPageSelected(int position) {
        currentPosition = position;
    }

}

然而，这种解决方案并不完美。从最后一个到第一个快速滑动时，它有一点缺陷。如果我们在很短的时间内滑动两次，第二张幻灯片将无效。这个问题需要解决。

Answer 9

是一个简单的例子，监听器的重要部分是对循环终点的STATE_IDLE的检测。 因此，首先实现OnPageChangeListener类，然后在您的处理程序类上添加以下部分：

@Override
    public void onPageScrollStateChanged(int state) {

        if (state == ViewPager.SCROLL_STATE_IDLE) {

            if (mPreviousPosition == mCurrentPosition && !mIsEndOfCycle) {

                if (mCurrentPosition == 0) {
                    mViewPager.setCurrentItem(getAdapterItemsCount() - 1);
                } else {
                    mViewPager.setCurrentItem(0);
                }

                mIsEndOfCycle = true;
            } else {
                mIsEndOfCycle = false;
            }

            mPreviousPosition = mCurrentPosition;
        }

    }

Answer 10

解决了从右向左滑动第一页到最后一页时反复出现的动画，反之亦然

@tobi_b回答略有修改，解决了我的问题。 为此，将起始页和最后一页的最后一页的副本添加到最后一页。然后从PagerAdapter中的以下方法中删除NOT运算符。将setCurrentItem（lastposition，false）更改为setCurrentItem（lastposition-1，false）和setCurrentItem（0，false）为setCurrentItem（1，false）。

private void setNextItemIfNeeded() {
    if (isScrollStateSettling()) {
        handleSetNextItem();
    }
}

private boolean isScrollStateSettling() {
    return mScrollState == ViewPager.SCROLL_STATE_SETTLING;
}
private void handleSetNextItem() {
    final int lastPosition = pager.getAdapter().getCount() - 1;
    if(mCurrentPosition == 0) {
        pager.setCurrentItem(lastPosition-1, false);
    } else if(mCurrentPosition == lastPosition) {
       pager.setCurrentItem(1, false);
    }
}

在您的MainActivity.java中，不要忘记将当前项设置为1。 希望这会有所帮助。