spinbox和slider

#-------------------------------------------------
#
# Project created by QtCreator 2020-05-03T01:20:40
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = spinbox
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which has been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

CONFIG += c++11

SOURCES += 
        main.cpp 
        spinbox.cpp

HEADERS += 
        spinbox.h

FORMS += 
        spinbox.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

spinbox.h

#ifndef SPINBOX_H
#define SPINBOX_H

#include <QMainWindow>
#include <QDialog>
#include <QLabel>
#include <QPushButton>
#include <QTime>
#include <QString>
#include <QTimer>

namespace Ui {
class spinbox;
}

class spinbox : public QMainWindow
{
    Q_OBJECT

public:
    explicit spinbox(QWidget *parent = nullptr);
    ~spinbox();
private:
    Ui::spinbox *ui;
};

#endif // SPINBOX_H

spinbox.cpp

#include "spinbox.h"
#include "ui_spinbox.h"

spinbox::spinbox(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::spinbox)
{
    ui->setupUi(this);
    connect(ui->spinBox, SIGNAL(valueChanged(int)), ui->slider, SLOT(setValue(int)));
    connect(ui->slider, SIGNAL(valueChanged(int)), ui->spinBox, SLOT(setValue(int)));
}

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

main.cpp

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

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

    return a.exec();
}