Signal & Slot in QT

QObject.connect(sender, “2signal( )”,reciver,”1slot()”);

 1 class QExample : public QObject
 2 {
 3 
 4        Q_OBJECT
 5 
 6 public:
 7        QTestA (QObject *parent );
 8 
 9        ~QTestA ();
10 signals:
11        void SignalA1 ();
12        void SignalA2 (int i );
13 
14 public slots:
15        void SlotA1 ();
16        void SlotA2 (char *szBuf ,int nSize );
17 private:
18 
19 public:
20 
21 int qt_metacall (QMetaObject ::Call _c , int _id , void **_a )
22 {
23     _id = QObject ::qt_metacall (_c , _id , _a );
24     if (_id < 0)
25         return _id ;
26     if (_c == QMetaObject ::InvokeMetaMethod ) 
27    {
28         switch (_id ) {
29         case 0: SignalA1 (); break ;
30         case 1: SignalA2 ((*reinterpret_cast < int (*)>(_a [1]))); break ;
31         case 2: SlotA1 (); break ;
32         case 3: SlotA2 ((*reinterpret_cast < char *(*)>(_a [1])),(*reinterpret_cast < int (*)>(_a [2]))); break ;
33         default : ;
34          }
35         _id -= 4;
36     }
37     return _id ;
38 }
39       
40 
41 }; 

1  QMetaObject 
2 {
3     const QMetaObject *superdata ;
4     const char *stringdata ; //save class name, signal name, parameter name,slot name, all ended by ‘/0‘
5     const uint *data ; //int array, store information of QMetaObjectPrivate
6 }

 1 struct QMetaObjectPrivate
 2 
 3 {
 4 
 5     int revision ;
 6     int className ;
 7     int classInfoCount , classInfoData ;
 8     int methodCount , methodData ;
 9     int propertyCount , propertyData ;
10     int enumeratorCount , enumeratorData ;
11     int constructorCount , constructorData ;
12 }; 

 1 static const uint qt_meta_data_Q QExampleData[] = {
 2        2,       // revision
 3        0,       // classname
 4        0,    0, // classinfo  
 5        4,   12, // methods and its data
 6        0,    0, // properties
 7        0,    0, // enums/sets
 8        0,     0, // constructors
 9        // 以上部分 是QMetaObjectPrivate 结构信息
10        // signals: signature, parameters, type, tag, flags
11        8,    7,    7,    7, 0x05,
12       21,   19,    7,    7, 0x05,
13       // slots: signature, parameters, type, tag, flags
14       35,    7,    7,    7, 0x0A,
15       56,   44,    7,    7, 0x0A,
16       0        // end
17 }; 

// slots: signature, parameters, type, tag, flags
1 static const char qt_meta_stringdata_Q QExampleMetaData [] = {
2     "QTestA/0/0SignalA1()/0i/0SignalA2(int)/0"
3     "SlotA1()/0szBuf,nSize/0SlotA2(char*,int)/0"
4 }; 

 1 QMetaObject::connect(sender, signal_index,receiver, method_index,type, types);
 2 QObject *s =const_cast<QObject*>(sender);
 3 QObject*r = const_cast<QObject *>(receiver);
 4 
 5 QOrderedMutexLockerlocker(&s->d_func()->threadData->mutex,                       &r->d_func()->threadData->mutex);
 6 
 7 QObjectPrivate::Connection c;
 8 
 9 c.receiver = r;
10 c.method = method_index;
11 c.connectionType = type;
12 c.argumentTypes= types;
13 
14 s->d_func()->addConnection(signal_index, &c);
15 r->d_func()->refSender(s, signal_index);