Flutter Webivew加载指示器

Question

我当前正在使用flutter_webview_plugin，并试图在用户单击网站内的链接时添加加载指示器。我知道在最初加载网站时这是可能的，但是一旦用户进入网站并在webview中导航，就不知道如何实现。我当前的代码如下：

class _MyHomePageState extends State<MyHomePage> {
  final flutterWebviewPlugin = new FlutterWebviewPlugin();


  @override

  Widget build(BuildContext context) {
    return WebviewScaffold(
        url: "samplewebsite.com",
        withJavascript: true,
        withZoom: false,

        clearCookies: true,
        //clearCache: true,
        hidden: true,
        //withLocalStorage: false,

        appBar: AppBar(
          titleSpacing: 0.0,
        //title: Text("Sample Website"),
    backgroundColor: Color(0xFF021818),
    actions: <Widget>[
      InkWell(
        child: Icon(Icons.refresh),
        onTap: (){
          flutterWebviewPlugin.reload();
          },
      ),
      FlatButton(
        textColor: Colors.white,
        onPressed: () {
          flutterWebviewPlugin.reloadUrl("samplewebsite.com/page1");},
        child: Text("PAGE1"),
        shape: CircleBorder(side: BorderSide(color: Colors.transparent)),
      ),
      FlatButton(
        textColor: Colors.white,
        onPressed: () {
          flutterWebviewPlugin.reloadUrl("samplewebsite.com/page2");},
        child: Text("PAGE2"),
        shape: CircleBorder(side: BorderSide(color: Colors.transparent)),
      ),
      FlatButton(
              textColor: Colors.white,
              onPressed: () {
                flutterWebviewPlugin.reloadUrl("samplewebsite.com/login");},
              child: Text("LOGIN"),
              shape: CircleBorder(side: BorderSide(color: Colors.transparent)),
            ),
    ]),



    );
  }

任何对此的澄清将不胜感激。