QT入门笔记-自定义控件封装 30

具体代码如下:

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++17

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    main.cpp \
    smallwidget.cpp \
    widget.cpp

HEADERS += \
    smallwidget.h \
    widget.h

FORMS += \
    smallwidget.ui \
    widget.ui

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

#include "widget.h"

#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Widget w;
    w.show();
    return a.exec();
}

#include "smallwidget.h"
#include "ui_smallwidget.h"
#include <QDebug>
smallWidget::smallWidget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::smallWidget)
{
    ui->setupUi(this);
    //信号和槽中不需要写函数名后的() 注意重载 使用函数指针或者类型转换来表示
    connect(ui->spinBox,(void (QSpinBox:: *)(int))&QSpinBox::valueChanged,ui->horizontalSlider,&QSlider::setValue);
    connect(ui->horizontalSlider,&QSlider::valueChanged,ui->spinBox,&QSpinBox::setValue);
}

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

void smallWidget::getNum()
{
    qDebug()<<ui->spinBox->value();
}




void smallWidget::setNum(int n )
{
    ui->horizontalSlider->setValue(50);
}

#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();
public:
    void getNum();
    void setNum(int n);

private:
    Ui::smallWidget *ui;
};

#endif // SMALLWIDGET_H

#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    connect(ui->btn_get,&QPushButton::clicked,ui->widget,&smallWidget::getNum);
    connect(ui->btn_set,&QPushButton::clicked,ui->widget,&smallWidget::setNum);
}

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

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>

QT_BEGIN_NAMESPACE
namespace Ui {
class Widget;
}
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = nullptr);
    ~Widget();

private:
    Ui::Widget *ui;
};
#endif // WIDGET_H