1.pro

#-------------------------------------------------
#
# Project created by QtCreator 2013-09-26T13:32:37
#
#-------------------------------------------------

QT       += core gui network testlib

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = untitled
TEMPLATE = app


SOURCES += main.cpp\
        MainWindow.cpp

HEADERS  += MainWindow.h

FORMS    += MainWindow.ui

main.cpp

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

int main(int argc, char *argv[]) {
  QApplication app(argc, argv);
  MainWindow w;
  w.show();
  return app.exec();
}

MainWindow.cpp

#include "MainWindow.h"
#include "ui_MainWindow.h"
#include <QDebug>
#include <QMouseEvent>

#include "windows.h"
#include <QWindow>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
  ui->setupUi(this);
  show();
  HWND hwnd = reinterpret_cast<HWND>(effectiveWinId());
  LONG lStyle = GetWindowLong(hwnd, GWL_STYLE);
  lStyle &= ~(WS_CAPTION | WS_THICKFRAME | WS_MINIMIZE | WS_MAXIMIZE | WS_SYSMENU);
  SetWindowLong(hwnd, GWL_STYLE, lStyle);
  setWindowFlags(windowFlags() | Qt::FramelessWindowHint);
  windowHandle()->reportContentOrientationChange(Qt::PrimaryOrientation);
}



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

void MainWindow::mousePressEvent(QMouseEvent *e) {
  if (!isMaximized() && e->button() == Qt::LeftButton && ui->title->geometry().contains(e->pos())) {
    window_drag_start_pos = e->pos();
  }
}

void MainWindow::mouseReleaseEvent(QMouseEvent *e) {
  window_drag_start_pos = QPoint(0, 0);
}

void MainWindow::mouseMoveEvent(QMouseEvent *e) {
  if (!window_drag_start_pos.isNull()) {
    move(pos() + e->pos() - window_drag_start_pos);
  }
}

void MainWindow::on_minimize_clicked() {
  showMinimized();
}

void MainWindow::on_maximize_clicked() {
  if (isMaximized()) {
    showNormal();
  } else {
    showMaximized();
  }
}

MainWindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QStandardItemModel>
#include <QComboBox>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

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

private:
    Ui::MainWindow *ui;
    QPoint window_drag_start_pos;
    void mousePressEvent(QMouseEvent* e);
    void mouseReleaseEvent(QMouseEvent* e);
    void mouseMoveEvent(QMouseEvent* e);

private slots:

    void on_minimize_clicked();
    void on_maximize_clicked();
};

#endif // MAINWINDOW_H

MainWindow.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>526</width>
    <height>392</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralWidget">
   <layout class="QVBoxLayout" name="verticalLayout">
    <property name="margin">
     <number>0</number>
    </property>
    <item>
     <layout class="QHBoxLayout" name="horizontalLayout">
      <item>
       <widget class="QLabel" name="title">
        <property name="sizePolicy">
         <sizepolicy hsizetype="Expanding" vsizetype="Preferred">
          <horstretch>0</horstretch>
          <verstretch>0</verstretch>
         </sizepolicy>
        </property>
        <property name="text">
         <string>title</string>
        </property>
       </widget>
      </item>
      <item>
       <widget class="QPushButton" name="minimize">
        <property name="text">
         <string>minimize</string>
        </property>
       </widget>
      </item>
      <item>
       <widget class="QPushButton" name="maximize">
        <property name="text">
         <string>maximize</string>
        </property>
       </widget>
      </item>
     </layout>
    </item>
    <item>
     <widget class="QTableView" name="tableView"/>
    </item>
   </layout>
  </widget>
  <widget class="QStatusBar" name="statusBar"/>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <resources/>
 <connections/>
</ui>