Qt全屏显示和按键ESC退出全屏

1.需求描述

将播放窗口全屏显示，将工具栏边框等隐藏在后面；然后退出全屏通过ESC返回按钮；

2.实现方法

定义一个全屏的容器类，继承于QWidget；全屏时，去掉窗口的父窗口，然后全屏显示，不去掉父窗口指针无法全屏；按下ESC按钮后，通过keyPressEvent(QKeyEvent* pEvent);函数，将父窗口重新设置回去；

#ifndef FULLSCREEN_H
#define FULLSCREEN_H#include <QWidget>
#include <QKeyEvent>
class FullScreen : public QWidget
{Q_OBJECTpublic:FullScreen(QWidget *parent);~FullScreen();void SetFullScreen();void keyPressEvent(QKeyEvent* pEvent);
private:QWidget* parentwidget=NULL;
};#endif // FULLSCREEN_H

#include "FullScreen.h"
#include <QLayout>
FullScreen::FullScreen(QWidget *parent): QWidget(parent)
{}FullScreen::~FullScreen()
{}void FullScreen::SetFullScreen()
{parentwidget = parentWidget();parentWidget()->layout()->removeWidget(this);setParent(NULL);showFullScreen();raise();
}void FullScreen::keyPressEvent(QKeyEvent* pEvent)
{if (!pEvent->modifiers()){if (pEvent->key() == Qt::Key_Escape &&isFullScreen()){hide();//避免一闪而过
            showNormal();setParent(parentwidget);parentwidget->layout()->addWidget(this);show();pEvent->accept();return;}}QWidget::keyPressEvent(pEvent);
}