在连接语句中访问Qt信号的"有效载荷"

Question

如何在连接语句的lambda中访问信号的'有效载荷？

说信号看起来像这样：

signals:
  void stateChanged(std::pair<unsigned, unsigned>);

现在在Connect语句中，我想在lambda中访问std::pair，该怎么做？这样的东西：

connect(&sender, &sendClass::stateChanged, ()[]{ use content of std::pair for conversion here; emit other signal with converted content });

Answer 1

您必须提供lambda函数参数：

connect(&sender, &sendClass::stateChanged,
        (std::pair<unsigned, unsigned> state)[] { /*do something with state*/ });