如何在Flutter中启用/禁用ElevatedButton

有人知道如何启用/禁用 Flutter ElevatedButton 吗？我已经查看了文档，但看不到任何明显的内容。

class IcoButton extends StatelessWidget {
    IcoButton(
      {@required this.lbl,
      @required this.col,
      @required this.ico,
      @required this.onPress});

  final String lbl;
  final FaIcon ico;
  final MaterialColor col;
  final Function onPress;

  @override
  Widget build(BuildContext context) {
    return ElevatedButton.icon(
      label: Text(lbl),
      icon: ico,
      style: ElevatedButton.styleFrom(
        primary: col,
        onPrimary: Colors.white,
        minimumSize: Size(160.0, 60.0),
        textStyle: TextStyle(
          fontSize: 24,
        ),
      ),
      onPressed: onPress,
    );
     }
    }

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