我尝试从PackageInfo获取应用程序的版本，但值为空。救命啊！

PackageInfo packageInfo =
   await PackageInfo.fromPlatform();
print('package info: $packageInfo');

我尝试在终端打印PackageInfo：

PackageInfo(appName: MyApp, buildNumber: 3, version: )

正如你所看到的是从响应空的版本...我也试过：

Future getVersion() async {
    PackageInfo.fromPlatform().then((PackageInfo packageInfo) {
      setState(() {
        appName = packageInfo.appName;
        version = packageInfo.version;
        print('version: $version');
      });
    });
  }