WebViews在ViewPager不加载/渲染，直到页面显示 [英] WebViews in ViewPager are not loaded/rendered until page is shown

问题描述

我使用的是ViewPager许多WebViews，它是表示ePub格式。我的问题是，WebViews只是渲染/加载（我不是很确定）德恩及其相应的页面变得可见。在此之后的页面上不需要重新呈现，直到它从ViewPagerAdapter破坏。 其结果是，总是有一个白色的页面的一小会儿。我怎么能pre-使得它顺利滚动到下web视图（这是之前没有渲染）。

I use a ViewPager with many WebViews, it is for showing an ePub. My Problem is that the WebViews are just rendered/loaded (im not quite sure) wenn their corresponding page becomes visible. After this the page doesn't need to be re-rendered until it is destroyed from the ViewPagerAdapter. The consequence is that there is always a white page for a little while. How can i pre-render the page that it scrolls smooth to next webView (which was not rendered before).

这是我PagerAdapter：

This is my PagerAdapter:

public class MagazineReaderPagerAdapter extends PagerAdapter {

    private MagazineReaderActivity activity;
    private EpubDocument epub;

    public MagazineReaderPagerAdapter(Context ctx, EpubDocument epub)
    {
        activity = (MagazineReaderActivity) ctx;
        this.epub = epub;
    }

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

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        ReaderWebViewMulti view = new ReaderWebViewMulti(activity);
        view.loadContentDocument(epub.getContentDocuments().get(position), epub);

        ((ViewPager) container).addView(view, 0);
        return view;
    }

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

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

ReaderWebViewMulti从的WebView IND扩展实现的方法loadContentDocument至极加载通过loadDataWithBaseURL的内容。

ReaderWebViewMulti extends from WebView ind implements a method loadContentDocument wich loads the content via loadDataWithBaseURL.

编辑： 在活性的OnCreate的setOffscreenPageLimit被设置为3

edit: At activity-oncreate the setOffscreenPageLimit is set to 3

 viewPager.setOffscreenPageLimit(3);

要指出的是什么问题，我犯了一个小视频在 YouTube上

To point out what the problem is, i made a little video on YouTube

这是第二个4，你可以看到，每一页是刚刚呈现的时候已经是可见的。当我回去，一切都很好。

From second 4 you can see that every page is just rendered when it is already visible. When i go back everything is fine.

推荐答案

我有同样的问题，并通过禁用硬件加速Web视图固定它：

I had the same problem and fixed it by disabling hardware acceleration for the web view:

webView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);

请参阅<一href="http://stackoverflow.com/questions/8273327/webview-inside-viewpager-or-scrollview-weird-rendering-bug-on-android-3-0">WebView内ViewPager或滚动型 - Android电子奇怪的渲染错误3.0+

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