QT从入门到实战完整版 P30

自定义封装控件

smallWidgt.h

#ifndef SMALLWIDGET_H
#define SMALLWIDGET_H

#include <QWidget>

namespace Ui {
class SmallWidget;
}

class SmallWidget : public QWidget
{
    Q_OBJECT

public:
    explicit SmallWidget(QWidget *parent = nullptr);
    ~SmallWidget();
    //设置数字
    void setNum(int num);

    //获取数字
    int getNum();

private:
    Ui::SmallWidget *ui;
};

#endif // SMALLWIDGET_H

smallWidget.cpp

#include "smallwidget.h"
#include "ui_smallwidget.h"

SmallWidget::SmallWidget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::SmallWidget)
{
    ui->setupUi(this);
    //
    void(QSpinBox:: * spSignal)(int)=&QSpinBox::valueChanged;
    connect(ui->spinBox,spSignal,ui->horizontalSlider,&QSlider::setValue);
    //QSlider移动 QStringBox跟着移动
    connect(ui->horizontalSlider,&QSlider::valueChanged,ui->spinBox,&QSpinBox::setValue);

}
//设置数字
void SmallWidget::setNum(int num)
{
    ui->spinBox->setValue(num);
}
//获取数字
int SmallWidget::getNum()
{
    return ui->spinBox->value();
}
SmallWidget::~SmallWidget()
{
    delete ui;
}

Widget.cpp

#include "widget.h"
#include "ui_widget.h"
#include <QDebug>

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    //点击获取，获取当前控件的值
    connect(ui->pushButtonget,&QPushButton::clicked,[=](){
        qDebug()<<ui->widget_2->getNum();
    });
    //设置到一半
    connect(ui->pushButtonset,&QPushButton::clicked,[=](){
        ui->widget_2->setNum(50);
    });
}

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