Android 某些设备上的自定义ViewPager呈现问题

我开发了一种用于在应用程序中选择人员的滚动机制。这是一个自定义的视图寻呼机，允许每次在屏幕上显示一个以上的项目（在我的例子中是3个），并由两侧的阴影包围

以下是它在Nexus 5、Nexus 4、Galaxy S3等设备上的外观和工作原理：

但是在一些设备上，如（索尼Xperia，以及不同类型的摩托罗拉），渲染效果看起来很差，结果如下：

关于我在@commonware的博客文章中引用的代码：

第三个选项是你可以找到的代码

这是我的相关代码：

PagerContainer:

    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.
        if (Build.VERSION.SDK_INT >= 11 && Build.VERSION.SDK_INT < 19)
        {
            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) { 
        invalidate();
    }

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

  //Size View Pager:
    //========================================
    pagerSize = mContainerSize.getViewPager();
    adapter = new MySizePagerAdapter();
    pagerSize.setAdapter(adapter);
    //Necessary or the pager will only have one extra page to show  make this at least however many pages you can see
    pagerSize.setOffscreenPageLimit(adapter.getCount());
    //A little space between pages
    pagerSize.setPageMargin(15);
    //If hardware acceleration is enabled, you should also remove  clipping on the pager for its children.
    pagerSize.setClipChildren(false);

---

更多的研究让我明白，这个问题与硬件加速有关，或者与某些设备缺乏硬件加速有关。但是通过代码禁用它也没有帮助。

我会尝试将ViewPager的layerType及其子项设置为软件渲染，而不是父帧布局

---

您可能还想查看这篇博文：

我最终使用了另一个

ViewPager的实现，该实现给出了相同的结果，但渲染问题在哪里都看不到，这是代码：

  private class MyTypePagerAdapter extends PagerAdapter {

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

        TextView view = new TextView(getActivity());
        view.setText(mTempBeverageList.get(position).getName().toUpperCase());
        if (!wasTypeChanged && (!isLocaleHebrew  && position == 1))
        {
            view.setTypeface(null, Typeface.BOLD);
            view.setTextSize(19);
        }
        else
        {
            view.setTextSize(16);
        }
        view.setSingleLine();
        view.setGravity(Gravity.CENTER);
        view.setTextColor(getResources().getColor(R.color.cups_black));
        view.setBackgroundColor(getResources().getColor(R.color.cups_cyan));
        container.addView(view);
        return view;
    }

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

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

    @Override
    public float getPageWidth(int position) {
      return (0.33333f);
    }

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

初始化部分：

pagerType= (ViewPager) view.findViewById(R.id.pagerType);   
pagerType.setAdapter(new MyTypePagerAdapter());
pagerType.setOffscreenPageLimit(6);

谢谢你的回答，现在我更清楚地知道为什么会发生这种情况，但是你的解决方案和博客文章中的解决方案仍然没有帮助我。但是+1表示努力。