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

 1 //QObject数据基类
 2 class Q_CORE_EXPORT QObjectData {
 3 public:
 4     virtual ~QObjectData() = 0;
 5     QObject *q_ptr;
 6     QObject *parent;
 7     QObjectList children;
 8 
 9     uint isWidget : 1;
10     uint blockSig : 1;
11     uint wasDeleted : 1;
12     uint isDeletingChildren : 1;
13     uint sendChildEvents : 1;
14     uint receiveChildEvents : 1;
15     uint isWindow : 1; //for QWindow
16     uint unused : 25;
17     int postedEvents;
18     QDynamicMetaObjectData *metaObject;
19     QMetaObject *dynamicMetaObject() const;
20 };

//QObject数据基类

 1 //QObjectPrivate扩展数据
 2 struct ExtraData
 3 {
 4     ExtraData() {}
 5 #ifndef QT_NO_USERDATA
 6     QVector<QObjectUserData *> userData;
 7 #endif
 8     QList<QByteArray> propertyNames;
 9     QList<QVariant> propertyValues;
10     QVector<int> runningTimers;
11     QList<QPointer<QObject> > eventFilters; //事件过滤器数据集
12     QString objectName;
13 };

1 //QObjectPrivate数据概览
2 public:
3     ExtraData *extraData;    // extra data set by the user
4     QThreadData *threadData; // id of the thread that owns the object
5 
6     QObjectConnectionListVector *connectionLists; //最重要的：信号槽关联关系链表！
7 
8     Connection *senders;     // linked list of connections connected to this object
9     Sender *currentSender;   // object currently activating the object

    QMetaObject

 1 //QMetaObject核心数据类
 2 struct { // private data
 3     const QMetaObject *superdata; //最重要的：父类元对象！
 4     const QByteArrayData *stringdata;   //最重要的：字符串流，多种类信息！
 5     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！
 6     typedef void (*StaticMetacallFunction)(QObject *, QMetaObject::Call, int, void **);
 7     StaticMetacallFunction static_metacall;
 8     const QMetaObject * const *relatedMetaObjects;
 9     void *extradata; //reserved for future use
10 } 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。