QT槽函数

#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();
//槽函数声明
public slots:
    void FoodisComing();

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

#include "widget.h"
#include "ui_widget.h"
#include <QMessageBox>
//声明使用弹消息框的类
//点餐送达的按钮和弹消息
Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    connect(ui->pushButton,SIGNAL(clicked()),this,SLOT(FoodisComing()));
}

Widget::~Widget()
{
    delete ui;
}
//槽函数的定义
void Widget::FoodisComing()
{
    QMessageBox::information(this,tr("开始送餐"),tr("快递送达"));
}