Qt“私人插槽:"这是什么?

Qt quot;private slots:quot; what is this?(Qt“私人插槽:这是什么?)

问题描述

我知道如何使用它，但它的语法让我很困扰.什么是私人插槽:"在做什么?

I understand how to use it, but the syntax of it bothers me. What is "private slots:" doing?

我以前从未在类定义中看到 private 关键字和 : 之间的东西.这里有什么奇特的 C++ 魔法吗?

I have never seen something between the private keyword and the : in a class definition before. Is there some fancy C++ magic going on here?

这里的例子:

 #include <QObject>

 class Counter : public QObject
 {
     Q_OBJECT

 public:
     Counter() { m_value = 0; }

     int value() const { return m_value; }

 public slots:
     void setValue(int value);

 ...

推荐答案

Slots 是 C++ 的 Qt 特定扩展.它仅在通过 Qt 的预处理器元对象编译器 (moc) 发送代码后才进行编译.见 http://doc.qt.io/qt-5/moc.html 用于文档.

Slots are a Qt-specific extension of C++. It only compiles after sending the code through Qt's preprocessor, the Meta-Object Compiler (moc). See http://doc.qt.io/qt-5/moc.html for documentation.

正如弗兰克指出的，只有链接才需要 moc.额外的关键字是用标准预处理器#defined 去掉的.

As Frank points out, moc is only required for linking. The extra keywords are #defined away with the standard preprocessor.

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