Android视图寻呼机在滑动时翻转更多页面答案

【问题标题】：Android view Pager flip more pages on swipeAndroid视图寻呼机在滑动时翻转更多页面
【发布时间】：2014-10-29 14:40:47
【问题描述】：

我正在使用 ViewPager 和 FragmentStatePageAdapter 来显示用户可以通过的多个视图。在当前实现中每次滑动只会更改一个页面。相反，我想根据用户滑动浏览多个视图。如果滑动时间长/快，我需要翻阅多个视图，反之亦然。

这是我当前的代码

public class MyAdapter extends FragmentStatePagerAdapter 
{
        public MyAdapter(FragmentManager fragmentManager) {
            super(fragmentManager);
        }

        @Override
        public int getCount() {
            return 10;
        }

        @Override
        public Fragment getItem(int position) {
            return ItemFragment.init(position);
        }


    }

PageContainer 类

public class PagerContainer extends FrameLayout implements ViewPager.OnPageChangeListener {

    private ViewPager mPager;
    boolean mNeedsRedraw = false;

    public PagerContainer(Context context) {
        super(context);
        init();
    }

    public PagerContainer(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public PagerContainer(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    private void init() {
        //Disable clipping of children so non-selected pages are visible
        setClipChildren(false);

        //Child clipping doesn't work with hardware acceleration in Android 3.x/4.x
        //You need to set this value here if using hardware acceleration in an
        // application targeted at these releases.
        setLayerType(View.LAYER_TYPE_SOFTWARE, null);
    }

    @Override
    protected void onFinishInflate() {
        try {
            mPager = (ViewPager) getChildAt(0);
            mPager.setOnPageChangeListener(this);
        } catch (Exception e) {
            throw new IllegalStateException("The root child of PagerContainer must be a ViewPager");
        }
    }

    public ViewPager getViewPager() {
        return mPager;
    }

    private Point mCenter = new Point();
    private Point mInitialTouch = new Point();

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        mCenter.x = w / 2;
        mCenter.y = h / 2;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        //We capture any touches not already handled by the ViewPager
        // to implement scrolling from a touch outside the pager bounds.
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mInitialTouch.x = (int)ev.getX();
                mInitialTouch.y = (int)ev.getY();
            default:
                ev.offsetLocation(mCenter.x - mInitialTouch.x, mCenter.y - mInitialTouch.y);
                break;
        }

        return mPager.dispatchTouchEvent(ev);
    }

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        //Force the container to redraw on scrolling.
        //Without this the outer pages render initially and then stay static
        if (mNeedsRedraw) invalidate();
    }

    @Override
    public void onPageSelected(int position) { }

    @Override
    public void onPageScrollStateChanged(int state) {
        mNeedsRedraw = (state != ViewPager.SCROLL_STATE_IDLE);
    }
}

我如何在安卓中做到这一点？

谢谢

【问题讨论】：

标签： android android-fragments android-viewpager carousel fragmentstatepageradapter

【解决方案1】：

你可以通过调用来改变视图：

ViewPager.setCurrentItem(int index)
ViewPager.setCurrentItem(int index, bool animation)

您必须自己处理滑动命令，但在某张幻灯片上，您需要调用 ViewPager 的 setCurrentItem。 setCurrentItem 方法还允许您启用或禁用动画。

【讨论】：