图解Qt信号槽实现

https://blog.csdn.net/sun222555888/article/details/80642740

信号槽实现需了解如下基础组件

    QObject - 核心数据

//QObject数据基类
class Q_CORE_EXPORT QObjectData {
public:
    virtual ~QObjectData() = 0;
    QObject *q_ptr;
    QObject *parent;
    QObjectList children;

    uint isWidget : 1;
    uint blockSig : 1;
    uint wasDeleted : 1;
    uint isDeletingChildren : 1;
    uint sendChildEvents : 1;
    uint receiveChildEvents : 1;
    uint isWindow : 1; //for QWindow
    uint unused : 25;
    int postedEvents;
    QDynamicMetaObjectData *metaObject;
    QMetaObject *dynamicMetaObject() const;
};

//QObject数据基类

//QObjectPrivate扩展数据
struct ExtraData
{
    ExtraData() {}
#ifndef QT_NO_USERDATA
    QVector<QObjectUserData *> userData;
#endif
    QList<QByteArray> propertyNames;
    QList<QVariant> propertyValues;
    QVector<int> runningTimers;
    QList<QPointer<QObject> > eventFilters; //事件过滤器数据集
    QString objectName;
};

//QObjectPrivate数据概览
public:
    ExtraData *extraData;    // extra data set by the user
    QThreadData *threadData; // id of the thread that owns the object

    QObjectConnectionListVector *connectionLists; //最重要的：信号槽关联关系链表！

    Connection *senders;     // linked list of connections connected to this object
    Sender *currentSender;   // object currently activating the object

    QMetaObject

//QMetaObject核心数据类
struct { // private data
    const QMetaObject *superdata; //最重要的：父类元对象！
    const QByteArrayData *stringdata;   //最重要的：字符串流，多种类信息！
    const uint *data; //最重要的：二进制流，多种类信息。部分数据，通过Index索引从stringdata解析出来！
    typedef void (*StaticMetacallFunction)(QObject *, QMetaObject::Call, int, void **);
    StaticMetacallFunction static_metacall;
    const QMetaObject * const *relatedMetaObjects;
    void *extradata; //reserved for future use
} d;

如何通过QObject/QMetaObject实现信号槽
举个例子：初始阶段，老师的一个信号与学生的三个槽分别链接。程序启动后，触发老师的信号，然后学生的三个槽函数分别执行。

    简述元对象、QObject、子对象的关系；信号槽的链接
  

    一个信号触发后，如何调到槽函数的大致流程
 

关注核心类、核心数据的流动，不要深陷细节。