flutter - 错误:在flutter中只能在初始化程序中访问静态成员

Question

我试图解决此问题，但无法
我正在将数据传递给构造函数进行初始化并放入源中
有人能帮助我吗

插件:https://pub.dev/packages/flutter_ijkplayer

class FullScreen extends StatefulWidget {
  String url_ , userAgent;
  FullScreen(
    this.url_,
    this.userAgent,
  ) ;

  @override
  _FullScreenState createState() => _FullScreenState(this.url_, this.userAgent);
}

class _FullScreenState extends State<FullScreen> {
  var controller = IjkMediaController();
  String url , userAgent;


  _FullScreenState(this.url, this.userAgent);
  Orientation get orientation => MediaQuery.of(context).orientation;
  DataSource source = DataSource.network(
    widget.url_,------>ERROR : Error: Only static members can be accessed in initializers
    headers: {
      'User-Agent':widget.userAgent------>ERROR : Error: Only static members can be accessed in initializers
    }
  );


  @override
  initState() async {
    controller.setDataSource(source, autoPlay: true);
    super.initState();
  }

Answer 1

您只能访问静态成员初始化。要使变量静态化，请在变量声明的前面使用static关键字。

static String url;

但是如果你。不想将其设为静态，则可以按以下方式在initistate中初始化该变量。

var controller;
  Orientation get orientation => MediaQuery.of(context).orientation;
  DataSource source;
  @override
  void initState() {
    super.initState();
    controller = IjkMediaController();
    source =
        DataSource.network(widget.url_, headers: {'User-Agent': widget.url_});
    controller.setDataSource(source, autoPlay: true);
  }