Qt之自建标题栏

  在项目中遇到Linux环境重Dialog在双击标题栏时对话框会最大化的情况，
在设置MaxmiumSize等都没有效果的情况下所以自设标题栏。
大体思路是通过三个空间组成标题栏的图标、标题、关闭按键，
并且通过鼠标事件来控制框体的移动。
通过继承QDialog，将标题栏和将所要显示的内容的Widget组合起来，
通过GetCurChildWidget()接口将Widget接口暴露出来供后续填充自己想要的Widget，
这样便可以将项目中需要使用Dialog的部件统一风格。

// TitileBar.h
#ifndef __TITLEBAR_H_
#define __TITLEBAR_H_

#include <QDialog>

class QEvent;
class QMouseEvent;
class QPixmap;
class QColor;
class QLabel;
class QPushButton;
class QPoint;
class QString;

class TitleBar : public QWidget
{
    Q_OBJECT
    Q_PROPERTY(QColor TitleColor READ getTitleColor WRITE setTitleColor )
public:
    TitleBar(QWidget* parent = 0,Qt::WindowFlags f = 0);
    ~TitleBar();
    void SetWindowTitle(QString& strTitle);
    void SetWindowIcon(QPixmap& pixTitle);
    QColor getTitleColor();
    void setTitleColor(QColor& col);
protected:
    void mousePressEvent(QMouseEvent* event);    /// 重写鼠标按压事件
    void mouseMoveEvent(QMouseEvent* event);     /// 重写鼠标移动事件
    void mouseReleaseEvent(QMouseEvent* event);  /// 重新鼠标释放事件
private:
    bool isLeftMousePressed;
    QString strTypeface;
    int32_t ulScreenWidht; 
    QPoint HistoryPos;
    QLabel* WindowTitleLab;
    QLabel* TitleIconLab;
    QPushButton* CloseBtn;
    QColor TitleColor;
signals:
    void CloseBtnClickEvent();
private slots:
    void on_CloseBtn_Pressed();
};

#endif //TitleBar.h

// TitleBar.cpp
#include "TitleBar.h"
#include <QMouseEvent>
#include <QPixmap>
#include <QColor>
#include <QLabel>
#include <QPushButton>
#include <QPoint>
#include <QString>
#include "CStaticDatas.h" // 主要是获取控件分辨率的一些函数

TitleBar::TitleBar(QWidget* parent,Qt::WindowFlags flags)
    :isLeftMousePressed(false)
{
    CStaticDatas *cStaticDatas = CStaticDatas::getCStaticDatasInstance();
    strTypeface = cStaticDatas->getFont();
    ulScreenWidht = cStaticDatas->getScreenWidth();   /// 获取分辨率
    HistoryPos.setX(0);
    HistoryPos.setY(0);
    setWindowFlags(Qt::FramelessWindowHint);
    TitleIconLab = new QLabel(this);
    TitleIconLab->setObjectName("TitleIconLab");
    TitleIconLab->setFixedSize(20,20);
    QPixmap pix;
    pix.load(":/SubIcon/SbuIcon/unitteclogo.png");
    TitleIconLab->setPixmap(pix);
    TitleIconLab->setScaledContents(true);
    TitleIconLab->setStyleSheet("QLabel#TitleIconLab{border:0px;};");

    WindowTitleLab = new QLabel(this);
    WindowTitleLab->setObjectName("WindowTitleLab");
    WindowTitleLab->setPixmap(QPixmap(20,20));
    WindowTitleLab->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Fixed);
    QString strWindowTitle = "QLabel#WindowTitleLab{border:0px;font-size:" + QString::number(ulScreenWidht / 68) \
                             + "px;font-family:" + strTypeface + "; };";
    WindowTitleLab->setStyleSheet(strWindowTitle);

    CloseBtn = new QPushButton(this);
    CloseBtn->setIcon(QIcon(":/SubIcon/SbuIcon/Close.png"));
    CloseBtn->setFixedSize(20,20);
    CloseBtn->setObjectName("CloseBtn");
    CloseBtn->setStyleSheet("QPushButton#CloseBtn{border:0px;}");

    QHBoxLayout* TitleLayout = new QHBoxLayout;
    TitleLayout->addWidget(TitleIconLab,0,Qt::AlignLeft);
    TitleLayout->addWidget(WindowTitleLab,0,Qt::AlignCenter);
    TitleLayout->addWidget(CloseBtn,0,Qt::AlignRight);
    TitleLayout->setContentsMargins(2,0,2,0);
    connect(CloseBtn,SIGNAL(clicked()),this,SLOT(on_CloseBtn_Pressed()));
    setLayout(TitleLayout);
}
TitleBar::~TitleBar()
{

}

void TitleBar::SetWindowTitle(QString& strTitle)
{
    WindowTitleLab->setText(strTitle);
}
void TitleBar::SetWindowIcon(QPixmap& pixTitle)
{
    TitleIconLab->setPixmap(pixTitle);
}

void TitleBar::mousePressEvent(QMouseEvent*event)
{
    if(event->button() == Qt::LeftButton)
    {
        HistoryPos = event->globalPos();
        isLeftMousePressed = true;
    }
}

void TitleBar::mouseMoveEvent(QMouseEvent* event)
{
    if(isLeftMousePressed == true)
    {
        parentWidget()->move(parentWidget()->geometry().topLeft() \
            + event->globalPos() - HistoryPos);
        HistoryPos = event->globalPos();
    }
}

void TitleBar::mouseReleaseEvent(QMouseEvent* event)
{
    if(event->button() == Qt::LeftButton)
    {
        isLeftMousePressed = false;
    }
}

void TitleBar::on_CloseBtn_Pressed()
{
    emit CloseBtnClickEvent();
}

QColor TitleBar::getTitleColor()
{
    return palette().window().color();
}

void TitleBar::setTitleColor(QColor& col)
{
    QPalette pale = palette();
    pale.setColor(QPalette::Background, col);
    setAutoFillBackground(true);
    setPalette(pale);
}

//  Dis_Dialog.h
#ifndef _DIS_DIALOG_H__
#define _DIS_DIALOG_H__

#include <QDialog>
#include <QColor>
#include "TitleBar.h"

class QWidget;
class QVBoxLayout;

class dialog : public QDialog
{
    Q_OBJECT
public:
    dialog(QWidget *parent = 0, Qt::WFlags flags = 0);
    ~dialog();
    void SetWindowTitle(QString& title);      /// 设置标题栏文字
    void SetWindowIcon(QPixmap& pixTitle);    /// 设置标题栏图标
    QColor GetTitleColor();                   /// 获取标题栏背景色
    bool SetTitleColor(QColor& col);                /// 设置标题栏背景色
    QWidget* GetCurChildWidget();             /// 获取当前对话框的内容栏，共外部组件使用
    void SetDlgLayoutStretch(int,int);              /// 设置标题栏和内容框比例 一般2：9就够用了，可以调
private:
    QWidget* widget;
    TitleBar* titleBar;
    QVBoxLayout* MainLayout;
};

#endif //DIS_Dialog.h

// Dis_Dialog.cpp
#include <QWidget>
#include <QEvent>
#include <QLabel>
#include <QMouseEvent>
#include <QPushButton>
#include <QHBoxLayout>
#include <QVBoxLayout>

/// 对话框构造函数
dialog::dialog(QWidget *parent, Qt::WFlags flags)
{
    setWindowFlags(Qt::FramelessWindowHint);
    titleBar = new TitleBar;
    QColor TitleColor(255,193,37);
    titleBar->setProperty("TitleColor",TitleColor);

    widget = new QWidget();
    widget->setObjectName("widget");
    MainLayout = new QVBoxLayout();
    MainLayout->addWidget(titleBar);
    MainLayout->addWidget(widget);
    SetDlgLayoutStretch(2,9);
    MainLayout->setContentsMargins(2,0,2,2);
    MainLayout->setSpacing(0);
    connect(titleBar,SIGNAL(CloseBtnClickEvent()),this,SLOT(close()));
    //setFixedSize(600,400);
    setLayout(MainLayout);
}
dialog::~dialog()
{

}
/// 设置标题栏的文字
void dialog::SetWindowTitle(QString& title)
{
    titleBar->SetWindowTitle(title);
}
/// 设置标题栏的图标
void dialog::SetWindowIcon(QPixmap& pixTitle)
{
    titleBar->SetWindowIcon(pixTitle);
}
/// 返回对话框的widget
QWidget* dialog::GetCurChildWidget()
{
    return widget;
}
/// 获取标题栏颜色
QColor dialog::GetTitleColor()
{
    return titleBar->property("TitleColor").value<QColor>();
}
/// 设置标题栏颜色
bool dialog::SetTitleColor(QColor& col)
{
    return titleBar->setProperty("TitleColor",QVariant(col));
}
void dialog::SetDlgLayoutStretch(int TitleBarFactor,int ContentFactor)
{
    MainLayout->setStretch(0,TitleBarFactor);
    MainLayout->setStretch(1,ContentFactor);
}

最后，代码和思路上参考如下博文：
https://blog.51cto.com/9291927/2330380