加载进度等于100，但未显示文件。
尝试更改路径尝试从西里尔文更改为拉丁文尝试externalStorageDir

@override
  void initState() {
    controller
      ..setJavaScriptMode(JavaScriptMode.unrestricted)
      ..enableZoom(true)
      ..setBackgroundColor(const Color(0x00000000))
      ..setNavigationDelegate(
        NavigationDelegate(
          onProgress: (int progress) {
            printMessage("viewer progress : $progress");
          },
          onPageStarted: (String url) {},
          onPageFinished: (String url) {},
          onWebResourceError: (WebResourceError error) {
            setState(() {
              canRenderFile = false;
            });
            printMessage("error viewer ${error.description}");
          },
        ),
      );
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    printMessage(widget._path ?? "");
    if (canRenderFile) {
      controller.loadFile(widget._path ?? "");
    }
    if (canRenderFile == true) {
      return WebViewWidget(controller: controller);
    } else {
      return DownloadFileView(
        fileName: widget.file?.name ?? "",
        fileSize: widget.file?.fileSize.toUiSize().toString() ?? "",
        onAction: () {
          widget.onDownload?.call();
        },
      );
    }
  }
}

这是我的代码canRenderFile是默认=真