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_OBJECTpublic:    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的构造函数中：

    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();
}