1.创建一个空的QT工程文件

2 建立程序文件

MainWindow.h

#ifndef MAINWINDOW_H

#define MAINWINDOW_H

#include<QMainWindow>

class MainWindow : public QMainWindow{

    Q_OBJECT

public:

    MainWindow();

};

#endif // MAINWINDOW_H

MainWindow.cpp

#include<QtGui>

#include"MainWindow.h"

MainWindow::MainWindow(){

    QWidget *widget=new QWidget;

    setCentralWidget(widget);

    QWidget *topfiller=new QWidget;

    topfiller->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);

    QWidget *bottomFiller=new QWidget;

    bottomFiller->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);

    QVBoxLayout *layout=new QVBoxLayout;

    layout->addWidget(topfiller);

    layout->addWidget(bottomFiller);

    widget->setLayout(layout);

    setWindowTitle(tr("Main Window"));

    resize(512,480);

}

Main.cpp

#include<QApplication>

#include"MainWindow.h"

int main(int argc,char* argv[]){

    QApplication app(argc,argv);

    MainWindow wnd;

    wnd.show();

    app.exec();

}