自 Android 7 起，WebView 显示空白页

Question

以下代码在 Android 7 之前的设备上运行良好。Android 7 和 8 WebView 显示空白屏幕而不是某些内容：

java部分：

public static class QuickIntroFragment1 extends Fragment{
        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
            View view = inflater.inflate(R.layout.layout_web_view, container, false);
            WebView wv = (WebView) view.findViewById(R.id.wv_intro);
            wv.loadUrl("file:///android_res/raw/learn_methodology.html");
            return view;
        }
    }

AndroidManifest 已包含必要的权限：

<uses-permission android:name="android.permission.INTERNET" />

本地html 部分位于下方，但其他网址（例如 google.com）也未显示：

    <!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8" />
    <title>Word Dolphin documentation</title>
    <style type="text/css">
      ul{
      margin-left:-17px;
      }
    </style>
</head>
<body>
<p>Language learning consists of several parts: skill of creating and understanding of sentences, vocabulary filling, pronunciation training and communication skills. Word Dolphin helps to learn words and prevent to forget it.</p>
<ul>
    <li>if you want to come to a mutual understanding you need to know about 3000 words. 7-9  thousand words will be sufficient for everyday communication. Where to get these words? Firstly, you can search by phrases similar to "1000 most popular words". Secondly, just read in the learning language. Preferably, these texts on the well-known theme. So, except the most popular words, you obtain living language samples.</li>
    <li>after you have found the unknown word, add it to WordDolphin and define translation. In fact, there may be a lot of meanings of the word. But you should learn 3 or 4 most used meanings. Learn it. Optimal quantity is 2 or 3 meanings because more will be difficult to remember. For many languages, Google or Microsoft Translator shows the most used meanings, pronunciation samples, etc.</li>
    <li>after you have added unknown words with translations, you can remember them. First learn few words, for example 5, and step by step increase its quantity. The main rule here: they should be easy to remember. It is necessary to listen to pronunciation and try to repeat it. Very good practice to remember words is writing.</li>
    <li>finally, check the meaning. It is necessary because learned words will be forgotten fast without practice. Firstly repeat newly learned words, then the rest. Word Dolphin keeps up your skills and based on it will create checklist.</li>
</ul>
<p>For read more tap ☰ and select <b>Info</b>.</p>
<p>Good work!</p>
</body>
</html>

此行为出现在 Google Android 模拟器上。所以this 不是我的问题。

Answer 1

似乎是我的硬件有问题，因为使用更强大的硬件和相同的模拟图像，我没有观察到这个错误。