利用setWindowFlags可以对widget的标题栏进行各种控制。详见代码注释：
 
#include "widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
{
    //setWindowFlags(Qt::CustomizeWindowHint);//无标题栏
    setWindowFlags(Qt::WindowTitleHint);//有标题栏和关闭按钮，但是没有最大最小化按钮，且关闭按钮不起作用
    //setWindowFlags(Qt::WindowCloseButtonHint);//使关闭按钮发挥作用
    //setWindowFlags(Qt::WindowMinMaxButtonsHint);//有最大最小化按钮，但关闭按钮不起作用
}

Widget::~Widget()
{

}
 
下图是使用Qt::WindowTitleHint的效果。尽管标题栏中有关闭按钮，但按钮没有激活。
 

XTitleWidget.h文件
 
#ifndef XTITLEWIDGET_H
#define XTITLEWIDGET_H

#include <QFrame>

namespace Ui {
class XTitleWidget;
}

class XTitleWidget : public QFrame
{
    Q_OBJECT

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

    void SetMainWidget(QWidget *pMainWidget);
    void SetTitle(QString title);

    // QWidget interface
protected:
    virtual void mousePressEvent(QMouseEvent *) override;
    virtual void mouseReleaseEvent(QMouseEvent *) override;
    virtual void mouseMoveEvent(QMouseEvent *) override;
    virtual void mouseDoubleClickEvent(QMouseEvent *) override;
    virtual void resizeEvent(QResizeEvent*) override;

    void UpdateTitle(QString title);

private slots:
    void on_xtitlewidget_close_clicked();

private:
    Ui::XTitleWidget *ui;

    bool m_bMouseDown = false;
    QPoint m_lastPt;

    QWidget * m_pMainWidget = nullptr;

    QString m_title = "";
};

#endif // XTITLEWIDGET_H
 
XTitleWidget.cpp
 
#include "XTitleWidget.h"
#include "ui_XTitleWidget.h"

#include <QMouseEvent>

XTitleWidget::XTitleWidget(QWidget *parent) :
    QFrame(parent),
    ui(new Ui::XTitleWidget)
{
    ui->setupUi(this);

    setWindowOpacity(0.7);
}

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

void XTitleWidget::SetMainWidget(QWidget *pMainWidget)
{
    m_pMainWidget = pMainWidget;
}

void XTitleWidget::SetTitle(QString title)
{
    m_title = title;
    UpdateTitle(m_title);
}

//处理鼠标点击窗体移动
void XTitleWidget::mousePressEvent(QMouseEvent *event)
{
    if (event->button() == Qt::LeftButton)
    {
        m_bMouseDown = true;
        m_lastPt = event->globalPos();
    }
}

void XTitleWidget::mouseMoveEvent(QMouseEvent *event)
{
    do
    {
        if(!m_bMouseDown)
        {
            break;
        }

        if(nullptr == m_pMainWidget)
        {
            break;
        }

        if(m_pMainWidget->isMaximized())
        {
            break;
        }

        int x = m_pMainWidget->pos().x();
        int y = m_pMainWidget->pos().y();

        QPoint dif = event->globalPos() - m_lastPt;
        m_pMainWidget->move(x + dif.x(), y + dif.y());
        m_lastPt = event->globalPos();
    }while(false);


}

void XTitleWidget::mouseReleaseEvent(QMouseEvent *event)
{
    Q_UNUSED(event);
    m_bMouseDown = false;
}


void XTitleWidget::mouseDoubleClickEvent(QMouseEvent *event)
{
    if (event->button() == Qt::LeftButton)
    {

    }
}

void XTitleWidget::resizeEvent(QResizeEvent *e)
{
    UpdateTitle(m_title);
    QWidget::resizeEvent(e);
}

void XTitleWidget::UpdateTitle(QString title)
{
    QFontMetrics elidfont(font());
    QString txt = elidfont.elidedText(title, Qt::ElideMiddle, ui->xtitlewidget_title_label->width());
    ui->xtitlewidget_title_label->setText(txt);
}

void XTitleWidget::on_xtitlewidget_close_clicked()
{
    if(nullptr != m_pMainWidget)
    {
        m_pMainWidget->close();
    }
}
 
XTitleWidget.ui
 
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>XTitleWidget</class>
 <widget class="QWidget" name="XTitleWidget">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>423</width>
    <height>30</height>
   </rect>
  </property>
  <property name="minimumSize">
   <size>
    <width>0</width>
    <height>30</height>
   </size>
  </property>
  <property name="maximumSize">
   <size>
    <width>16777215</width>
    <height>30</height>
   </size>
  </property>
  <property name="windowTitle">
   <string>Form</string>
  </property>
  <layout class="QGridLayout" name="gridLayout">
   <property name="leftMargin">
    <number>10</number>
   </property>
   <property name="topMargin">
    <number>0</number>
   </property>
   <property name="rightMargin">
    <number>19</number>
   </property>
   <property name="bottomMargin">
    <number>0</number>
   </property>
   <property name="spacing">
    <number>0</number>
   </property>
   <item row="0" column="0">
    <layout class="QHBoxLayout" name="horizontalLayout">
     <item>
      <widget class="QLabel" name="xtitlewidget_title_label">
       <property name="sizePolicy">
        <sizepolicy hsizetype="Ignored" vsizetype="Preferred">
         <horstretch>0</horstretch>
         <verstretch>0</verstretch>
        </sizepolicy>
       </property>
       <property name="text">
        <string/>
       </property>
      </widget>
     </item>
     <item>
      <spacer name="horizontalSpacer">
       <property name="orientation">
        <enum>Qt::Horizontal</enum>
       </property>
       <property name="sizeType">
        <enum>QSizePolicy::Preferred</enum>
       </property>
       <property name="sizeHint" stdset="0">
        <size>
         <width>10</width>
         <height>20</height>
        </size>
       </property>
      </spacer>
     </item>
     <item>
      <widget class="QPushButton" name="xtitlewidget_close">
       <property name="minimumSize">
        <size>
         <width>20</width>
         <height>20</height>
        </size>
       </property>
       <property name="maximumSize">
        <size>
         <width>20</width>
         <height>20</height>
        </size>
       </property>
       <property name="text">
        <string/>
       </property>
      </widget>
     </item>
    </layout>
   </item>
  </layout>
 </widget>
 <resources/>
 <connections/>
</ui>
 
 

 
 
 
  
2019独角兽企业重金招聘Python工程师标准>>>  
 
 
 
 
转子 http://blog.csdn.net/liang19890820/article/details/50555298
 
 
/头文件
#ifndef TITLE_BAR
#define TITLE_BAR

#include <QWidget>

class QLabel;
class QPushButton;

class TitleBar : public QWidget
{
    Q_OBJECT

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

protected:

    // 双击标题栏进行界面的最大化/还原
    virtual void mouseDoubleClickEvent(QMouseEvent *event);

    // 进行鼠界面的拖动
    virtual void mousePressEvent(QMouseEvent *event);

    // 设置界面标题与图标
    virtual bool eventFilter(QObject *obj, QEvent *event);

private slots:

    // 进行最小化、最大化/还原、关闭操作
    void onClicked();

private:

    // 最大化/还原
    void updateMaximize();

private:
    QLabel *m_pIconLabel;
    QLabel *m_pTitleLabel;
    QPushButton *m_pMinimizeButton;
    QPushButton *m_pMaximizeButton;
    QPushButton *m_pCloseButton;
};

#endif // TITLE_BAR
 
 
//实现文件
#include <QLabel>
#include <QPushButton>
#include <QHBoxLayout>
#include <QEvent>
#include <QMouseEvent>
#include <QApplication>
#include "title_bar.h"

#ifdef Q_OS_WIN
#pragma comment(lib, "user32.lib")
#include <qt_windows.h>
#endif

TitleBar::TitleBar(QWidget *parent)
    : QWidget(parent)
{
    setFixedHeight(30);

    m_pIconLabel = new QLabel(this);
    m_pTitleLabel = new QLabel(this);
    m_pMinimizeButton = new QPushButton(this);
    m_pMaximizeButton = new QPushButton(this);
    m_pCloseButton = new QPushButton(this);

    m_pIconLabel->setFixedSize(20, 20);
    m_pIconLabel->setScaledContents(true);

    m_pTitleLabel->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);

    m_pMinimizeButton->setFixedSize(27, 22);
    m_pMaximizeButton->setFixedSize(27, 22);
    m_pCloseButton->setFixedSize(27, 22);

    m_pTitleLabel->setObjectName("whiteLabel");
    m_pMinimizeButton->setObjectName("minimizeButton");
    m_pMaximizeButton->setObjectName("maximizeButton");
    m_pCloseButton->setObjectName("closeButton");

    m_pMinimizeButton->setToolTip("Minimize");
    m_pMaximizeButton->setToolTip("Maximize");
    m_pCloseButton->setToolTip("Close");

    QHBoxLayout *pLayout = new QHBoxLayout(this);
    pLayout->addWidget(m_pIconLabel);
    pLayout->addSpacing(5);
    pLayout->addWidget(m_pTitleLabel);
    pLayout->addWidget(m_pMinimizeButton);
    pLayout->addWidget(m_pMaximizeButton);
    pLayout->addWidget(m_pCloseButton);
    pLayout->setSpacing(0);
    pLayout->setContentsMargins(5, 0, 5, 0);

    setLayout(pLayout);

    connect(m_pMinimizeButton, SIGNAL(clicked(bool)), this, SLOT(onClicked()));
    connect(m_pMaximizeButton, SIGNAL(clicked(bool)), this, SLOT(onClicked()));
    connect(m_pCloseButton, SIGNAL(clicked(bool)), this, SLOT(onClicked()));
}

TitleBar::~TitleBar()
{

}

void TitleBar::mouseDoubleClickEvent(QMouseEvent *event)
{
    Q_UNUSED(event);

    emit m_pMaximizeButton->clicked();
}

void TitleBar::mousePressEvent(QMouseEvent *event)
{
#ifdef Q_OS_WIN
    if (ReleaseCapture())
    {
        QWidget *pWindow = this->window();
        if (pWindow->isTopLevel())
        {
           SendMessage(HWND(pWindow->winId()), WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
        }
    }
       event->ignore();
#else
#endif
}

bool TitleBar::eventFilter(QObject *obj, QEvent *event)
{
    switch (event->type())
    {
    case QEvent::WindowTitleChange:
    {
        QWidget *pWidget = qobject_cast<QWidget *>(obj);
        if (pWidget)
        {
            m_pTitleLabel->setText(pWidget->windowTitle());
            return true;
        }
    }
    case QEvent::WindowIconChange:
    {
        QWidget *pWidget = qobject_cast<QWidget *>(obj);
        if (pWidget)
        {
            QIcon icon = pWidget->windowIcon();
            m_pIconLabel->setPixmap(icon.pixmap(m_pIconLabel->size()));
            return true;
        }
    }
    case QEvent::WindowStateChange:
    case QEvent::Resize:
        updateMaximize();
        return true;
    }
    return QWidget::eventFilter(obj, event);
}

void TitleBar::onClicked()
{
    QPushButton *pButton = qobject_cast<QPushButton *>(sender());
    QWidget *pWindow = this->window();
    if (pWindow->isTopLevel())
    {
        if (pButton == m_pMinimizeButton)
        {
            pWindow->showMinimized();
        }
        else if (pButton == m_pMaximizeButton)
        {
            pWindow->isMaximized() ? pWindow->showNormal() : pWindow->showMaximized();
        }
        else if (pButton == m_pCloseButton)
        {
            pWindow->close();
        }
    }
}

void TitleBar::updateMaximize()
{
    QWidget *pWindow = this->window();
    if (pWindow->isTopLevel())
    {
        bool bMaximize = pWindow->isMaximized();
        if (bMaximize)
        {
            m_pMaximizeButton->setToolTip(tr("Restore"));
            m_pMaximizeButton->setProperty("maximizeProperty", "restore");
        }
        else
        {
            m_pMaximizeButton->setProperty("maximizeProperty", "maximize");
            m_pMaximizeButton->setToolTip(tr("Maximize"));
        }

        m_pMaximizeButton->setStyle(QApplication::style());
    }
}
 
 
Widget::Widget(QWidget *parent)
    : QWidget(parent)
{
    setWindowFlags(Qt::FramelessWindowHint | windowFlags());

    TitleBar *pTitleBar = new TitleBar(this);
    installEventFilter(pTitleBar);

    resize(400, 300);
    setWindowTitle("Custom Window");
    setWindowIcon(QIcon(":/Images/logo"));

    QPalette pal(palette());
    pal.setColor(QPalette::Background, QColor(50, 50, 50));
    setAutoFillBackground(true);
    setPalette(pal);

    QVBoxLayout *pLayout = new QVBoxLayout();
    pLayout->addWidget(pTitleBar);
    pLayout->addStretch();
    pLayout->setSpacing(0);
    pLayout->setContentsMargins(0, 0, 0, 0);
    setLayout(pLayout);
}
 
 
installEventFilter必须在setWindowTitle、setWindowIcon之前调用，因为必须先安装事件过滤器，相应事件触发时，才会进入标题栏的eventFilter事件中。
 
 
 
  
 
    
  
 
 
 
 
转载于:https://my.oschina.net/hanxiaodong/blog/1537799

bool event(QEvent *event)
{
   
    if (event->type() == QEvent::NonClientAreaMouseButtonDblClick)
        qDebug() << "title double clicked event"