错误 CS1525：意外符号“?”，应为“.”在 monodevelop

Question

这是给我错误的代码：

s.GetWeight(out weightInLb, out weightInG, out weightInOz, out bool? isStable);

 Error CS1525: Unexpected symbol `?', expecting `.'

这段代码调用函数GetWeight，代码如下：

 public void GetWeight(out decimal? weightInLb, out decimal? weightInG, out decimal? weightInOz, out bool? isStable)

我做错了什么？请帮忙！

编辑

如果我更换 ?与一个。我收到错误：

Error CS0117: `bool' does not contain a definition for `isStable'

Answer 1

您似乎在尝试使用 out variables，但您的编译器不支持它。所以用老式的方式来做

bool? isStable;
s.GetWeight(out weightInLb, out weightInG, out weightInOz, out isStable);

Error CS1525: Unexpected symbol `?', expecting `.' in monodevelop