QT屏幕保护程序二

前面我们用继承QApplication的方式实现了屏幕保护，

接下了用第二种方式：

首先定义一个屏保类：

#ifndef SPLASHSCREEN_H #define SPLASHSCREEN_H #include <QWidget> #include "mainwindow.h" namespace Ui { class SplashScreen; } class SplashScreen : public QWidget { Q_OBJECT public: explicit SplashScreen(QWidget *parent = 0); ~SplashScreen(); protected: void keyPressEvent(QKeyEvent *e); private: Ui::SplashScreen *ui; }; #endif // SPLASHSCREEN_H 

cpp.文件

#include "splashscreen.h" #include "ui_splashscreen.h" #include <QImage> #include <QDebug> SplashScreen::SplashScreen(QWidget *parent) : QWidget(parent), ui(new Ui::SplashScreen) { ui->setupUi(this); QImage *image = new QImage(":/style/ui_image/load.png"); ui->label->setPixmap(QPixmap::fromImage(*image)); } SplashScreen::~SplashScreen() { delete ui; } void SplashScreen::keyPressEvent(QKeyEvent *e) { this->hide(); ((MainWindow*)this->parentWidget())->currentWidgetChanged(3); } 

主函数中：

 QApplication app(argc, argv);

MainWindow mainWin;

    mainWin.show();

    app.installEventFilter(&mainWin);

return app.exec();

将mainWin注册一个焦点过滤事件，写一个定时器的槽函数

mainwindow.h文件中添加：

private slots:

void splashTimeTimeoutSlot();

protected:

    bool eventFilter(QObject *obj, QEvent *event);

private：

QWidget *pSplashTimeWidget = Q_NULLPTR;

//定义一个计时器，多久进入屏幕保护

QTimer splashTime;

//重写过滤事件函数

mainwindow.cpp文件中实现两个函数：
在mainwindow的构造函：
pSplashTimeWidget = new SplashScreen(this);

    pSplashTimeWidget->hide();

connect(&splashTime,SIGNAL(timeout()),this,SLOT(splashTimeTimeoutSlot()));

//实例化并隐藏

bool MainWindow::eventFilter(QObject *obj, QEvent *event)

{

    if (event->type() == QEvent::KeyPress) {

        //        if(sysInfo.sleeptime = "")

        //   {

        splashTime.start(5000);

    }

    return QObject::eventFilter(obj, event);

}

void MainWindow::splashTimeTimeoutSlot()
{    pSplashTimeWidget->show();

    pSplashTimeWidget->grabKeyboard();

}