新建Qt Widgets Application

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QPushButton>
#include <QMainWindow>
#include <QHBoxLayout>
class QPushButton;
namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
     QPushButton *btnNormal_;
     QPushButton *btnCheck_;
     QPushButton *btnMenu_;
     QPushButton *btnFlat_;
     QHBoxLayout *layout;
};

#endif // MAINWINDOW_H

main.h

#include "mainwindow.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QPushButton>
#include <QMenu>
#include <QVBoxLayout>
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    // 1.正常
    btnNormal_ = new QPushButton("Normal Button", this);
    //btnNormal_->setFlat(true);
      //设置按钮的文本信息
     btnNormal_->setText("Test1");
    btnNormal_->setGeometry(20,30,100,40);

      //layout->addWidget(pushButton3D);
    // 2.可停驻

    btnCheck_ = new QPushButton("Toggle Button", this);
    btnCheck_->setCheckable(true);
    //btnCheck_->setChecked(true);
    btnCheck_->setFlat(true);
      //设置按钮的文本信息
    btnCheck_->setText("Test2");
    btnCheck_->setGeometry(150,30,100,40);


    // 3.带弹出式菜单
    btnMenu_ = new QPushButton( "Popup Button", this);
    QMenu *menu = new QMenu;
    menu->addAction("Open Item");
    menu->addAction("Save Item");
    menu->addMenu("More Item");
    menu->addSeparator();
    menu->addAction("Close Item");
    btnMenu_->setMenu(menu);
    btnMenu_->setGeometry(20,90,100,40);
     // 4.平坦样式
    btnFlat_ = new QPushButton("Flat Button", this);
    btnFlat_->setFlat(true);
    btnFlat_->setGeometry(150,90,100,40);

    QVBoxLayout *layout = new QVBoxLayout();
    layout->addWidget(btnNormal_);
    layout->addWidget(btnCheck_);
    layout->addWidget(btnMenu_);
    layout->addWidget(btnFlat_);

}

MainWindow::~MainWindow()
{
    delete ui;
}

结果显示如下：