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Q_OBJECT

程序员文章站 2022-06-24 16:31:15
#define Q_OBJECT \public: \ Q_OBJECT_CHECK \ QT_WARNING_PUSH \ Q_OBJECT_NO_OVERRIDE_WARNING \ static const QMetaObject staticMetaObject; \ virtual const QMetaObject *metaObject() const; \ virtual void *qt_metacast(const char *); \....
#define Q_OBJECT \
public: \
    Q_OBJECT_CHECK \
    QT_WARNING_PUSH \
    Q_OBJECT_NO_OVERRIDE_WARNING \
    static const QMetaObject staticMetaObject; \
    virtual const QMetaObject *metaObject() const; \
    virtual void *qt_metacast(const char *); \
    virtual int qt_metacall(QMetaObject::Call, int, void **); \
    QT_TR_FUNCTIONS \
private: \
    Q_OBJECT_NO_ATTRIBUTES_WARNING \
    Q_DECL_HIDDEN_STATIC_METACALL static void qt_static_metacall(QObject *, QMetaObject::Call, int, void **); \
    QT_WARNING_POP \
    struct QPrivateSignal {}; \
    QT_ANNOTATE_CLASS(qt_qobject, "")
  1. 公有QMetaObject静态对象staticMetaObject
  2. 私有qt_static_metacall静态函数
  3. virtual const QMetaObject *metaObject() const; \    用于获取类静态拥有的元对象
  4. virtual void *qt_metacast(const char *); \                   通过元对象获取对象指针
  5. virtual int qt_metacall(QMetaObject::Call, int, void **); \     用于信号槽机制

1:为该类型的所有对象共有,属于类变量。

2:  私有静态函数qt_static_metacall,类里使用

3.4.5 在MOC生成代码的时候会重写这些虚函数。

 

class QMetaObject {
struct { // private data
        const QMetaObject *superdata;
        const QByteArrayData *stringdata;
        const uint *data;
        typedef void (*StaticMetacallFunction)(QObject *, QMetaObject::Call, int, void **);
        StaticMetacallFunction static_metacall;
        const QMetaObject * const *relatedMetaObjects;
        void *extradata; //reserved for future use
    } d;
};
struct QArrayData
{
    QtPrivate::RefCount ref;
    int size;
    uint alloc : 31;
    uint capacityReserved : 1;

    qptrdiff offset; // in bytes from beginning of header
}

 

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Q_OBJECT

本文地址:https://blog.csdn.net/jadeshu/article/details/107060428