Android 检测ViewPager上的视图更改

我正在通过SwipeyTabsAdapter实现一个横向的库ViewPager viewPageExtensions（com.astuetz.ViewPager.extensions）。当视图发生变化时，是否需要拦截？以同样的方式，我可以知道用户在任何时候都处于什么样的视图中

ViewPager的代码

public class DiccionariuPagerAdapter extends PagerAdapter {

    protected transient Activity mContext;

    private int mLength = 0;

    public DiccionariuPagerAdapter(Activity context, int length) {
        mContext = context;
        mLength = length;
    }

    @Override
    public int getCount() {
        return mLength;
    }

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

        RelativeLayout v = new RelativeLayout(mContext);

        View vi; // Creating an instance for View Object
        LayoutInflater inflater = (LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        if (position == 0) {            
            vi = inflater.inflate(R.layout.diccionariu, null);
        }
        else if (position == 1) {
            vi = inflater.inflate(R.layout.conxugar, null);
        }
        else {
            vi = inflater.inflate(R.layout.traducir, null);
        }

        v.addView(vi);

        //v.addView(t);

        ((ViewPager) container).addView(v, 0);

        startUpdate(container);

        return v;
    }

    @Override
    public void destroyItem(View container, int position, Object view) {
        ((ViewPager) container).removeView((View) view);
    }

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

    @Override
    public void finishUpdate(View container) {}

    @Override
    public void restoreState(Parcelable state, ClassLoader loader) {}

    @Override
    public Parcelable saveState() {
        return null;
    }

    @Override
    public void startUpdate(View container) {}

}

---

非常感谢您使用当前物品：

int itemId = ViewPager.getCurrentItem()

这样，您就可以使用从适配器检索实际视图

Adapter.getItem(itemId)

您还可以使用监听器

OnPageChangeListener

viewPager.setOnPageChangeListener(new OnPageChangeListener...

编译和工作：

~~~

---

setOnPageChangeListener

现在不推荐使用，但我们可以使用

addOnPageChangeListener

/

removeOnPageChangeListener

。

    mPager.setOnPageChangeListener(new OnPageChangeListener()
    {
        @Override
        public void onPageSelected(int position) 
        {
                // if listener is set - when using an indicator, must update that here
                mIndicator.setCurrentItem(position);

                String msg = "onPageSelected - position: " + position;
                Log.d("debug1", msg);
        }

        @Override
        public void onPageScrollStateChanged(int state) {}

        @Override
        public void onPageScrolled(int position, float arg1, int arg2) {}
    });