#include <QApplication>

#include <QSpinBox>

#include <QHBoxLayout>

#include <QLabel>

int main(int argc, char *argv[])

{

    QString qsum;

    QApplication app(argc,argv);

    QWidget *window = new QWidget;

    window->setWindowTitle("just change at the same time");

    QSpinBox *spinBox1 = new QSpinBox;

    spinBox1->setRange(0,39);

    QLabel *label1 = new QLabel;

    label1->setText("hello");

    QLabel *label2 = new QLabel;

    label2->setText("hello");

    QSpinBox *spinBox3 = new QSpinBox;

    spinBox3->setRange(0,39);

    int sum = spinBox1->value() + spinBox3->value();

    qsum = (QString) sum;

    QObject::connect(spinBox1, SIGNAL(valueChanged(QString)), label1, SLOT(setText(QString)));

    QObject::connect(spinBox1, SIGNAL(valueChanged(int)), label2, SLOT( setNum(int)));

    //QObject::connect(spinBox1, SIGNAL(valueChanged(int)), spinBox3, SLOT(setValue(int)));

    spinBox1->setValue(4);

    QHBoxLayout *layout = new QHBoxLayout;

    layout->addWidget(spinBox1);

    layout->addWidget(label1);

    layout->addWidget(label2);

    layout->addWidget(spinBox3);

    window->setLayout(layout);

    window->show();

    return app.exec();

}

运行截图如下：

http://s4/middle/500bd63ctc796b28cbfb3&690第一步实现 联动"  TITLE="qt 第一步实现 联动" />