QSpinBox用于整数的显示和输入，一般显示十进制数，也可以显示二进制、十六进制数，而且可以在显示框中增加前缀和后缀。QDoubleSpinBox用于浮点数的显示和输入，可以设置显示小数位数，也可以设置显示的前缀和后缀。

样式示例

代码示例
SpinBoxDemoDialog.h

#ifndef SPINBOXDEMODIALOG_H
#define SPINBOXDEMODIALOG_H

#include <QDialog>

namespace Ui
{
    class SpinBoxDemoDialog;
}

class SpinBoxDemoDialog : public QDialog
{
    Q_OBJECT

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

private slots:
    void on_decimalism_sb_valueChanged(int arg1);

private:
    Ui::SpinBoxDemoDialog* ui;
};

#endif // SPINBOXDEMODIALOG_H

SpinBoxDemoDialog.cpp

#include "SpinBoxDemoDialog.h"
#include "ui_SpinBoxDemoDialog.h"

SpinBoxDemoDialog::SpinBoxDemoDialog(QWidget* parent)
    : QDialog(parent)
    , ui(new Ui::SpinBoxDemoDialog)
{
    ui->setupUi(this);
    this->setWindowTitle("SpinBoxDemo");
    //后缀
    ui->num_sp->setSuffix("kg");
    //最小值
    ui->num_sp->setMinimum(0);
    //最大值
    ui->num_sp->setMaximum(255);
    //当前显示的值
    ui->num_sp->setValue(5);
    //前缀
    ui->signal_price->setPrefix("$");
    //单击上下调整按钮时的单步改变值
    ui->signal_price->setSingleStep(0.1);
    ui->all_price->setPrefix("$");
    ui->all_price->setSingleStep(1);
    //二进制
    ui->binary_sb->setDisplayIntegerBase(2);
    //十进制
    ui->decimalism_sb->setDisplayIntegerBase(10);
    //十六进制
    ui->sexadecimal_sb->setDisplayIntegerBase(16);
}

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

void SpinBoxDemoDialog::on_decimalism_sb_valueChanged(int arg1)
{
    ui->binary_sb->setValue(arg1);
    ui->sexadecimal_sb->setValue(arg1);
}