Android related

The build env. 

ensure that your computer’s BIOS is set up to support Intel’s virtualization extensions

using x86 emulator

>=8G RAM

SSD is preferred. 

if using in linux, make sure that you can run 32-bit Linux binaries

 sudo apt-get install libncurses5:

manifest

 change android:allowBackup to be false

 

webview

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_about);
    WebView wv = findViewById(R.id.about);
    wv.loadUrl("file:///android_asset/about.html");
}

the android_assets folder must be under app/source/main/assets. but the visit address is : 

file:///android_asset/about.html

why?