QTCreator：类之间的信号槽机制

Question

如果您不从类中制作对象（仅从类中继承），则如何在两个类之间求解信号/插槽机制？ Qtimer，QSerialport，哪个是信号的来源，在第二类中，您建立连接？

是这样的方法吗？

就我而言。我有两个类USB2CAN_DRIVER和CANVIEW。 USB2CAN_DRIVER 从QSerialport继承，该QSerialport继承了Qiodevice包含信号（readyRead（））。 我知道，这在 Canview 中用于与Handler Subroutine read_u2c（）连接，

我知道，在测试中，代码中是很多垃圾。

在 canview.cpp void canview :: on_connectport_release（）中是建立连接的，在 usb2can_driver.cpp int usb2can_driver :::::::: ConnectToport（QString PortName）是QSerialport继承的一部分。

每个答案我都会很高兴。如果您认为这个问题是错误提出的，请给我反馈。

usb2can_driver.h

#ifndef USB2CAN_DRIVER_H
#define USB2CAN_DRIVER_H

#include "QSerialPort"
#include "QTimer"
#include "QObject"
#include "QSignalSpy"


class USB2CAN_driver : public QSerialPort
{
    Q_OBJECT;

public:
    USB2CAN_driver();
    //virtual ~USB2CAN_driver();

    //QSerialPort *port_USB2CAN = new QSerialPort();


    int temporary_init_Counter = 0;
    int init();
    void USB_LoopBack();
    void Boot_Mode();
    void Config_Mode();
    void Normal_Mode();
    void LoopBack_Mode();
    QByteArray Get_Mode();

    void WriteReg(QByteArray regAdress, QByteArray value[]);
    QByteArray WriteCMD(QByteArray CMD_name, QByteArray value);
    QByteArray ReadReg(QByteArray regAdress);

    QString portName;
    int connectToPort(QString portName);
    int disconnectedFromPort();

    QTimer *tim;
    int tim_counter = 0;

public: signals:
    void readyRead();


private slots:
    QByteArray read_USB2CAN();
    void initSend();
    //void timEvent();

};

#endif // USB2CAN_DRIVER_H

usb2can_driver.cpp

#include "USB2CAN_define.h"
#include "QSerialPort"
#include "QSerialPort"
#include "QObject"
#include "QDebug"
#include <QSignalSpy>



USB2CAN_driver::USB2CAN_driver()
{
    //USB2CAN_driver:: = new QSerialPort();
    //USB2CAN_driver::Baud9600;
    //USB2CAN_driver::AllDirections;
    //qDebug() << "Open port" << USB2CAN_driver::open(QIODevice::ReadWrite);
}

/*
USB2CAN_driver::~USB2CAN_driver(){
    QObject::disconnect(USB2CAN_driver::,SIGNAL(readyRead()),USB2CAN_driver::,SLOT(QByteArray read_USB2CAN()));
}
*/

int USB2CAN_driver::connectToPort(QString portName){
    //port_USB2CAN.setPortName(portName);
    USB2CAN_driver::setPortName(portName);
    USB2CAN_driver::setBaudRate(QSerialPort::Baud9600,QSerialPort::AllDirections);
    USB2CAN_driver::setPortName(portName);
    //Reimplemented separately as signal of driver. !!!
    //qDebug() << "connect S&S in the driver, status: " << QObject::connect(this,SIGNAL(readyRead),this,SLOT(read_USB2CAN));
    //qDebug() << "connect S&S in the driver, status: " << connect(this,SIGNAL(readyRead()),this,SLOT(read_USB2CAN()));
    //QSignalSpy spy(this, SIGNAL(readyRead()));
    //qDebug() << "from driver" << spy.wait(5000) << "----" << spy.signal();
    tim = new QTimer;

    return USB2CAN_driver::open(QIODevice::ReadWrite);
}

/*
void USB2CAN_driver::timEvent(){
    qDebug() << "Tim" << tim_counter++;
    if(tim_counter >= 5){
        tim_counter = 0;
        tim->stop();
    }
}
*/

int USB2CAN_driver::disconnectedFromPort(){
    //QObject::disconnect(this,SIGNAL(readyRead()),this,SLOT(read_USB2CAN()));
    USB2CAN_driver::close();
    if(USB2CAN_driver::isOpen()){
        return 1;
    }
    else{
        qDebug() << "------------------Port is diconected-----------------";
        return 0;
    }
}


void USB2CAN_driver::USB_LoopBack(){
}
void USB2CAN_driver::Boot_Mode(){
}
void USB2CAN_driver::Config_Mode(){
}
void USB2CAN_driver::Normal_Mode(){
}
void USB2CAN_driver::LoopBack_Mode(){
}
QByteArray USB2CAN_driver::Get_Mode(){
    while(!USB2CAN_driver::waitForBytesWritten(300)){
        USB2CAN_driver::write(getMode);
    }
    return USB2CAN_driver::readAll(); //In progress...
}

void USB2CAN_driver::WriteReg(QByteArray regAdress, QByteArray value[]){
    int length = regAdress.length() + value->length();
    QByteArray len;
    len.setNum(length);
    QByteArray sendVal[] = { writeReg, len, regAdress, *value };
    QByteArray sendData;
    sendData.fromRawData(*sendVal,sizeof (sendVal));
    while(!USB2CAN_driver::waitForBytesWritten(300)){
        USB2CAN_driver::write(sendData);
    }
}
QByteArray USB2CAN_driver::WriteCMD(QByteArray CMD_name, QByteArray value){
}
QByteArray USB2CAN_driver::ReadReg(QByteArray regAdress){
}

int USB2CAN_driver::init(){
}

QByteArray USB2CAN_driver::read_USB2CAN(){
    qDebug() <<"From driver RX" << USB2CAN_driver::readAll();
    return USB2CAN_driver::readAll();
}

void USB2CAN_driver::initSend(){
}

canview.h

#define CANVIEW_H

#include <QDialog>
#include <usb2can_driver.h>

namespace Ui {
class CANview;
}

class CANview : public QDialog
{
    Q_OBJECT

public:
    explicit CANview(QWidget *parent = nullptr);
    ~CANview();

    USB2CAN_driver *u2c;
    QTimer *time;


private: signals:
    friend void USB2CAN_driver::readyRead();
private slots:
    void on_connectPort_released();

    void on_pushButton_released();

    QByteArray read_u2c();

    void timerSubrutine();

private:
    Ui::CANview *ui;
};

#endif // CANVIEW_H

canview.cpp

#include "ui_canview.h"
#include "QSignalSpy"

CANview::CANview(QWidget *parent) : QDialog(parent),ui(new Ui::CANview)
{
    ui->setupUi(this);
    u2c = new USB2CAN_driver;

}

CANview::~CANview()
{
    delete ui;   
}

//connect fcn
void CANview::on_connectPort_released()
{
    if(u2c->isOpen()){
        u2c->disconnectedFromPort();
    }
    else{
        u2c->connectToPort(ui->inputNamePort->text());
        qDebug() << "Connect rx task, status: " << connect(???,SIGNAL(readyRead()),this,SLOT(read_u2c()));
        connect(u2c->tim,SIGNAL(timeout()),this,SLOT(timerSubrutine()));
        u2c->tim->start(800);

    }

    //Controll of opened/close port
    if(u2c->isOpen()){
        ui->connectPort->setCheckState(Qt::CheckState::Checked);
    }
    else{
        ui->connectPort->setCheckState(Qt::CheckState::Unchecked);
    }
}

//Send function
void CANview::on_pushButton_released()
{
    u2c->write(ui->TX_textBrowser->toPlainText().toLatin1(),static_cast<int>(ui->TX_textBrowser->toPlainText().length()));
    qDebug() << "Send: " << static_cast<int> (ui->TX_textBrowser->toPlainText().length());
    QSignalSpy spy(u2c,SIGNAL(readyRead()));
    qDebug() << spy.signal() << spy.signalsBlocked() << spy.isValid();
}

QByteArray CANview::read_u2c(){
    qDebug() << "RX:" << u2c->readAll();
    ui->RX_textBrowser_2->setPlainText(u2c->readAll());
    return u2c->readAll();
}

void CANview::timerSubrutine(){
    qDebug() << "TimerEvent" << u2c->tim_counter++;
    if(u2c->tim_counter >= 5){
        u2c->tim->stop();
    }
}```

Answer 1

无法如 @Scheff的猫所述连接类。

解决方案是不要在 usb2can_driver 中使用QSerialport的继承。如果我想通过插槽（是第二类）连接QSerialport的信号，则必须在USB2CAN_DRIVER的构造函数中创建一个对象。

此对象允许使用信号/插槽机制。

简而
对于第二类（Canview）中的连接，我使用了此语法：

connect(u2c->port_USB2CAN,SIGNAL(readyRead()),this,SLOT(read_u2c()));

感谢Scheff的Cat，您的评论很有帮助。该解决方案正在起作用，但是如果有人看到非标准语法，请警告我。