Qt 使用线程 访问modbus485 读写仪器仪表参数 c++ 代码实例 不采用继承Qthread 重写run 的方法实现

以下是使用 Qt 线程和 Modbus 库实现访问 Modbus 485 读写仪器仪表参数的 C++ 代码示例，不采用继承 QThread 重写 run 的方法实现：

// modbusworker.h
#ifndef MODBUSWORKER_H
#define MODBUSWORKER_H

#include <QObject>
#include <QModbusDevice>
#include <QModbusTcpClient>

class ModbusWorker : public QObject
{
    Q_OBJECT

public:
    explicit ModbusWorker(QObject *parent = nullptr);
    void setConnectionParameters(QString host, quint16 port);
    void setDeviceAddress(int address);
    bool connectDevice();
    void readData(int startAddress, int numberOfValues);
    void writeData(int startAddress, int value);

signals:
    void dataRead(QVector<quint16> data);
    void dataWritten();

private:
    QModbusDevice *modbusDevice;
    QString connectionHost;
    quint16 connectionPort;
    int deviceAddress;
};

#endif // MODBUSWORKER_H

// modbusworker.cpp
#include "modbusworker.h"

ModbusWorker::ModbusWorker(QObject *parent)
    : QObject(parent)
{
    modbusDevice = new QModbusTcpClient(this);
}

void ModbusWorker::setConnectionParameters(QString host, quint16 port)
{
    connectionHost = host;
    connectionPort = port;
}

void ModbusWorker::setDeviceAddress(int address)
{
    deviceAddress = address;
}

bool ModbusWorker::connectDevice()
{
    if (!modbusDevice)
        return false;

    modbusDevice->setConnectionParameter(QModbusDevice::NetworkAddressParameter, connectionHost);
    modbusDevice->setConnectionParameter(QModbusDevice::NetworkPortParameter, connectionPort);
    modbusDevice->setConnectionParameter(QModbusDevice::SerialPortNameParameter, "COM1");
    modbusDevice->setConnectionParameter(QModbusDevice::SerialParityParameter, "EvenParity");
    modbusDevice->setConnectionParameter(QModbusDevice::SerialBaudRateParameter, 9600);
    modbusDevice->setConnectionParameter(QModbusDevice::SerialDataBitsParameter, 8);
    modbusDevice->setConnectionParameter(QModbusDevice::SerialStopBitsParameter, 1);
    modbusDevice->setTimeout(1000);
    modbusDevice->setNumberOfRetries(3);

    if (!modbusDevice->connectDevice()) {
        return false;
    }

    return true;
}

void ModbusWorker::readData(int startAddress, int numberOfValues)
{
    if (!modbusDevice)
        return;

    if (auto *reply = modbusDevice->sendReadRequest(QModbusDataUnit(QModbusDataUnit::HoldingRegisters,
                                                                      startAddress, numberOfValues),
                                                     deviceAddress)) {
        if (!reply->isFinished()) {
            connect(reply, &QModbusReply::finished, this, [=]() {
                if (reply->error() == QModbusDevice::NoError) {
                    emit dataRead(reply->result().values());
                }
                reply->deleteLater();
            });
        } else {
            delete reply;
        }
    } else {
        emit dataRead(QVector<quint16>());
    }
}

void ModbusWorker::writeData(int startAddress, int value)
{
    if (!modbusDevice)
        return;

    if (auto *reply = modbusDevice->sendWriteRequest(QModbusDataUnit(QModbusDataUnit::HoldingRegisters,
                                                                       startAddress, 1),
                                                      QVector<quint16>{static_cast<quint16>(value)},
                                                      deviceAddress)) {
        if (!reply->isFinished()) {
            connect(reply, &QModbusReply::finished, this, [=]() {
                if (reply->error() == QModbusDevice::NoError) {
                    emit dataWritten();
                }
                reply->deleteLater();
            });
        } else {
            delete reply;
        }
    } else {
        emit dataWritten();
    }
}

// mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "modbusworker.h"

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void on_connectPushButton_clicked();
    void on_readPushButton_clicked();
    void on_writePushButton_clicked();

    void on_dataRead(QVector<quint16> data);
    void on_dataWritten();

private:
    Ui::MainWindow *ui;
    ModbusWorker *modbusWorker;
};

#endif // MAINWINDOW_H

// mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QMessageBox>
#include <QThread>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
    , modbusWorker(new ModbusWorker(this))
{
    ui->setupUi(this);

    connect(modbusWorker, &ModbusWorker::dataRead, this, &MainWindow::on_dataRead);
    connect(modbusWorker, &ModbusWorker::dataWritten, this, &MainWindow::on_dataWritten);
}

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

void MainWindow::on_connectPushButton_clicked()
{
    if (ui->tcpConnectionRadioButton->isChecked()) {
        modbusWorker->setConnectionParameters(ui->hostLineEdit->text(),
                                               ui->portSpinBox->value());
    } else if (ui->serialConnectionRadioButton->isChecked()) {
        // Set serial connection parameters
    }

    modbusWorker->setDeviceAddress(ui->deviceAddressSpinBox->value());

    if (!modbusWorker->connectDevice()) {
        QMessageBox::warning(this, "Error", "Unable to connect to Modbus device.");
    }
}

void MainWindow::on_readPushButton_clicked()
{
    modbusWorker->readData(ui->startAddressSpinBox->value(),
                           ui->numberOfValuesSpinBox->value());
}

void MainWindow::on_writePushButton_clicked()
{
    modbusWorker->writeData(ui->startAddressSpinBox->value(),
                            ui->writeValueSpinBox->value());
}

void MainWindow::on_dataRead(QVector<quint16> data)
{
    // Process read data
}

void MainWindow::on_dataWritten()
{
    // Process write data
}

在主界面中，通过连接不同的按钮和输入框，调用 ModbusWorker 类中的函数，实现连接 Modbus 设备、读取数据、写入数据等操作。而 ModbusWorker 类中的函数则使用 Qt Modbus 库提供的类和函数，实现连接 Modbus 设备、读写数据等操作，同时使用信号与槽机制将数据传递到主线程进行处理。