Qt实现上下文菜单
一、重载contextMenuEvent()事件处理函数,在重载的contextMenuEvent函数中显示QMenu对象:
widget.h文件
#ifndef WIDGET_H
#define WIDGET_H
#include <QWidget>
class QMenu;
class QAction;
namespace Ui {
class Widget;
}
class Widget : public QWidget
{
Q_OBJECT
public:
explicit Widget(QWidget *parent = 0);
~Widget();
protected:
void contextMenuEvent(QContextMenuEvent *event);
private:
Ui::Widget *ui;
QMenu * menu;
QAction * openAction;
QAction * saveAsAction;
};
#endif // WIDGET_H
widget.cpp文件
#include "widget.h"
#include "ui_widget.h"
#include <QMenu>
#include <QAction>
#include <QContextMenuEvent>
Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget),
menu(new QMenu(this)),
openAction(new QAction(QStringLiteral("打开"), this)),
saveAsAction(new QAction(QStringLiteral("另存为"), this))
{
ui->setupUi(this);
menu->addAction(openAction);
menu->addAction(saveAsAction);
}
Widget::~Widget()
{
delete ui;
}
void Widget::contextMenuEvent(QContextMenuEvent *event)
{
//显示菜单到鼠标右击即event发生的坐标处,这两种写法都行,最终都是用全局坐标
//this->menu->exec(this->mapToGlobal(event->pos()));
this->menu->exec(event->globalPos());
}
二、添加QAction对象到父窗口,即要设置上下文菜单的窗口,然后设置父窗口属性为Qt::ActionsContextMenu:
只需将Widget类的构造函数做如下更改,并去掉对contextMenuEvent函数的重载:
Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget),
menu(new QMenu(this)),
openAction(new QAction(QStringLiteral("打开"), this)),
saveAsAction(new QAction(QStringLiteral("另存为"), this))
{
ui->setupUi(this);
//menu->addAction(openAction);
//menu->addAction(saveAsAction);
this->addAction(openAction);
this->addAction(saveAsAction);
this->setContextMenuPolicy(Qt::ActionsContextMenu);
}