webview_scroll_demo.dart

class WebViewScrollDemoState extends State<WebViewDemo> {

  double _bodyHeight = 500;

  WebViewController _controller;

  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return SizedBox(
        height: _bodyHeight,
        child: Scrollable(
            viewportBuilder: (_, offset) {
              return WebViewport(
                offset: offset,
                clipBehavior: Clip.hardEdge,
                onScroll: _onScroll,
                child: WebView(
                  key: _webviewKey,
                  initialUrl: "https://juejin.cn",
                  onWebViewCreated: (controller) {
                    _controller = controller;
                  },
                  javascriptMode: JavascriptMode.unrestricted,
                  debuggingEnabled: true,
                ),
                contentHeight: _contentHeight,
              );
            },
          ),
      );
  }

  void _onScroll(Offset offset) {
    _controller?.evaluateJavascript(
        "window.scrollTo(0,${_webviewOffsetY.abs().ceil()})");
  }
}