如何合并Lambda代理

Question

我想做这个:

class Foo {

  static Func<string> sRunner;

  Func<string> _runner;

  public Foo(Func<string> runner){

    _runner = runner ?? sRunner ?? () => "Hey!";

  }
}

我在lambda上得到一个"无效表达式"术语.可以内联修复吗？

Answer 1

_runner = runner ?? sRunner ?? (() => "Hey!");