c++ - 两个对象 QT 之间的示例 SLOT/SIGNAL

Question

我的应用程序包含 2 个不同的对象(QObject 和 QMainWIndow)，我想知道如何使用 SLOT/SIGNAL 在它们之间进行通信。此外，现有更好的方法吗？

有人可以举一个简单的例子吗？谢谢 :)

sample

主窗口.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "ui_mainwindow.h"
#include "object.h"

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private:
    Ui::MainWindow *ui;

private slots:


};

#endif // MAINWINDOW_H

主窗口.cpp

#include "mainwindow.h"
#include "object.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    connect(ui->chkState, SIGNAL(clicked()), this, SLOT(object->chkState();));
}

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

对象.h

#ifndef OBJET_H
#define OBJET_H

#include "mainwindow.h"
#include <QMainWindow>
#include <QObject>

class Object : public QObject
{
    Q_OBJECT
public:
    explicit Object(QObject *parent = 0);
    bool state;

signals:

private slots:
    void chkState(Ui::MainWindow *ui);
};

#endif // OBJET_H

对象文件

#include "object.h"
#include "mainwindow.h"

Object::Object(QObject *parent) : QObject(parent)
{

}

void Object::chkState(Ui::MainWindow *ui)
{
    if (ui->chkState->isChecked())
    {
        ui->state->setText("true");
        state = true;
    }
    else
    {
        ui->state->setText("false");
        state = false;
    }
}

Answer 1

这是一个如何发出信号和槽的简单示例。

        #ifndef MAINWINDOW_H
        #define MAINWINDOW_H

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

        namespace Ui {
        class MainWindow;
        }

        class MainWindow : public QMainWindow
        {
            Q_OBJECT

        public:
            explicit MainWindow(QWidget *parent = 0);
            ~MainWindow();

        signals:
            void transmit_to_object(bool value);

        private slots:
            void receive_from_object(bool value);

            void on_checkBox_clicked();

        private:
            Ui::MainWindow *ui;
            object          m_object;
        };

        #endif // MAINWINDOW_H

    #ifndef OBJECT_H
    #define OBJECT_H

    #include <QObject>

    class object : public QObject
    {
        Q_OBJECT

        public:
            explicit object(QObject * parent = 0);

        signals:
            void transmit_to_gui(bool value);

        private slots:
            void receive_from_gui(bool value);

        private:
        bool state;

    };

    #endif // OBJECT_H

#include "mainwindow.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}

#include "mainwindow.h"
#include "ui_mainwindow.h"

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

    connect(&m_object,SIGNAL(transmit_to_gui(bool)),this,SLOT(receive_from_object(bool)));

    connect(this,SIGNAL(transmit_to_object(bool)),&m_object,SLOT(receive_from_gui(bool)));

}

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

void MainWindow::receive_from_object(bool value)
{
    if(value)
    {
        ui->lineEdit->setText("true");
    }
    else
    {
        ui->lineEdit->setText("false");
    }
}

void MainWindow::on_checkBox_clicked()
{
    if(ui->checkBox->isChecked())
    {
        emit transmit_to_object(true);
    }
    else
    {
        emit transmit_to_object(false);
    }

}

#include "object.h"
#include "mainwindow.h"

object::object(QObject *parent)
{

}

void object::receive_from_gui(bool value)
{
    state = value;

    emit transmit_to_gui(state);
}