Qt5.9自定义标题栏用法

本博客主要总结创建Qt工程时，不用系统自带的标题栏，而是用自定义的标题栏。其中，自定义标题栏主要原理是，屏蔽原来的标题栏，然后用QVBoxLayout垂直布局管理器，加载一个标题栏QWidget。其中，这个标题栏QWidget里面自定义标题栏的功能按钮，比如图标、图标内容、最大化按钮（QWidget::showMaximized()）、最小化按钮（QWidget::showMinimized()）、关闭按钮（QWidget::close()）。

下面的一个实例是自定义的一个标题栏。这个实例的主要代码是参考这篇博客里面的，我只是对其中进行了修改和封装了一层QWidget。自定义标题的功能主要封装在类title_bar里面，只需要调用该类title_bar，然后用一个垂直布局将其关联起来，就可以实现自定义标题栏。

主要参考代码博客地址：https://blog.csdn.net/liang19890820/article/details/50555298（作者：一去丶二三里）

注意，屏蔽主界面标题栏，只需要用下面这条语句就行：

setWindowFlags(Qt::FramelessWindowHint | windowFlags());

1.1新建一个widget工程，不要勾选ui界面。然后添加一个类，类名为title_bar，基类为QWidget。

然后分别在title_bar.h，title_bar.cpp，widget.h，widget.cpp，main.cpp分别添加如下代码。

title_bar.h

#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

title_bar.cpp

#include <QLabel>
#include <QPushButton>
#include <QHBoxLayout>
#include <QEvent>
#include <QMouseEvent>
#include <QApplication>
#include "title_bar.h"

#ifdef Q_OS_WIN
#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(30, 30);
    m_pMaximizeButton->setFixedSize(30, 30);
    m_pCloseButton->setFixedSize(30, 30);

    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");

    m_pTitleLabel->setContentsMargins(8,0,0,0);
    m_pTitleLabel->setAlignment(Qt::AlignLeft | Qt::AlignVCenter);

    m_pMinimizeButton->setIcon(QIcon(":/icon/minus.png"));
    m_pMaximizeButton->setIcon(QIcon(":/icon/maximize.png"));
    m_pCloseButton->setIcon(QIcon(":/icon/close.png"));

    QHBoxLayout *mainWidgetLayout = new QHBoxLayout(this);
    QWidget *mainWidget = new QWidget;
    QHBoxLayout *pLayout = new QHBoxLayout;

    mainWidgetLayout->addWidget(mainWidget);
    mainWidget->setLayout(pLayout);
    mainWidgetLayout->setMargin(0);
    pLayout->setContentsMargins(7,0,0,0);
    pLayout->setSpacing(0);
    mainWidget->setStyleSheet("QWidget{background-color:rgb(150,150,150);}");
    pLayout->addWidget(m_pIconLabel);    
    pLayout->addWidget(m_pTitleLabel);
    pLayout->addStretch();
    pLayout->addWidget(m_pMinimizeButton);
    pLayout->addWidget(m_pMaximizeButton);
    pLayout->addWidget(m_pCloseButton);

    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;
     default:
         return QWidget::eventFilter(obj, event);

     }
     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.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = 0);
    ~Widget();
};

#endif // WIDGET_H

widget.cpp

#include <QVBoxLayout>
#include <QPixmap>
#include <QIcon>
#include <QTableWidget>
#include <QPushButton>

#include "widget.h"
#include "title_bar.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
{
    setWindowFlags(Qt::FramelessWindowHint | windowFlags());

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

        resize(960, 640);
        setWindowTitle("Custom Window");
        setWindowIcon(QIcon(":/icon/24x24.ico"));

        QPalette pal(palette());
        pal.setColor(QPalette::Background, QColor(0, 0, 0));
        setAutoFillBackground(true);
        setPalette(pal);

        QTableWidget *tableListWidget = new QTableWidget;
        QPushButton *pushButton = new QPushButton("button");
        pushButton->setStyleSheet("QPushButton{background-color:rgb(115,115,115);color:white}");

        QVBoxLayout *pLayout = new QVBoxLayout();
        pLayout->addWidget(pTitleBar);
        pLayout->addWidget(pushButton);
        pLayout->addWidget(tableListWidget);
        pLayout->setSpacing(0);
        pLayout->setMargin(0);
        setLayout(pLayout);
}

Widget::~Widget()
{

}

main.cpp

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

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

    return a.exec();
}

1.2程序构建运行后，结果如下图所示：

附件1

源代码下载地址：https://download.csdn.net/download/naibozhuan3744/10552044

参考内容：

https://blog.csdn.net/liang19890820/article/details/50555298（主要参考）

https://blog.csdn.net/qq_28093585/article/details/78517358

https://blog.csdn.net/qq21497936/article/details/79223848