screen.h

#ifndef SCREEN_H
#define SCREEN_H

#include <QMainWindow>

class Screen : public QMainWindow
{
    Q_OBJECT

public:
    Screen(QWidget *parent = nullptr);
    ~Screen();
};
#endif // SCREEN_H

screen.cpp

#include "screen.h"
#include <QTextEdit>
#include <windows.h>

Screen::Screen(QWidget *parent)
    : QMainWindow(parent)
{
    setWindowTitle(tr("Splash Example"));
    QTextEdit* Edit = new QTextEdit(tr("Splash Example"));
    setCentralWidget(Edit);
    resize(600,450);
    Sleep(3000);

}

Screen::~Screen() {}

main.cpp

#include "screen.h"

#include <QApplication>
#include <QPixmap>
#include <QSplashScreen>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QPixmap PixMap("text.png");
    QSplashScreen Splash(PixMap);
    Splash.show();
    a.processEvents();//展示画面 界面  然可以响应鼠标等操作
    Screen w;
    w.show();
    Splash.finish(&w);
    return a.exec();
}

运行图

启动图片

启动后程序