flutter - 取消不必要的声明以调用流取消

Question

我有 flutter 的代码，可以创建一个流并在处置期间取消该流:

 @override
  void dispose()  {
    if (_playerSubscription != null) {
      _playerSubscription.cancel;
      _playerSubscription = null;
    }
    super.dispose();
  }

问题是，当我将代码提交到pub.dev时，静态分析器会发出以下错误:
Avoid using unnecessary statements.
该错误在该行上发出:

_playerSubscription.cancel;

我已经检查了async.dart中的代码，它使用与我完全相同的三行代码。

Answer 1

cancel()是一种方法。您需要像这样更改它:

  @override
  void dispose()  {
    if (_playerSubscription != null) {
      _playerSubscription.cancel();
      _playerSubscription = null;
    }
    super.dispose();
  }