Qt无边框设计

//指定窗口为无边框
this->setWindowFlags(Qt::FramelessWindowHint | Qt::WindowMinMaxButtonsHint);
 

重写鼠标事件：

void mousePressEvent(QMouseEvent* event) override;
void mouseMoveEvent(QMouseEvent* event) override;

定义位置：

QPoint diff_pos;//鼠标和窗口的相对位移
	QPoint window_pos;//绝对位置
	QPoint mouse_pos;

void QtWidgetsApplication2::mousePressEvent(QMouseEvent * event)
{
	mouse_pos = event->globalPos();
	window_pos = this->pos();
	diff_pos = mouse_pos - window_pos;
 
}
 
void QtWidgetsApplication2::mouseMoveEvent(QMouseEvent * event)
{
	QPoint pos = event->globalPos();
	this->move(pos - diff_pos);
}

再创建一个widget作为标题栏，并定义好控件：

#include 
#include 
#include 
 
class CTitleBar : public QWidget
{
	Q_OBJECT
 
public:
	CTitleBar(QWidget *parent = nullptr);
	~CTitleBar();
 
private:
	void init();
 
private:
	QLabel* logo;
	QLabel* title;
	QPushButton* set;
	QPushButton* min;
	QPushButton* max;
	QPushButton* close;
};

初始化控件：

void CTitleBar::initUI()
{
	logo = new QLabel(this);
	title = new QLabel(this);
	title->setText(u8"标题");
	title->setFixedWidth(120);
 
	set = new QPushButton(this);
	set->setFixedSize(32, 32);
 
	min = new QPushButton(this);
	min->setFixedSize(32, 32);
 
	max = new QPushButton(this);
	max->setFixedSize(32, 32);
 
	close = new QPushButton(this);
	close->setFixedSize(32, 32);
 
	QHBoxLayout* lay = new QHBoxLayout(this);
	lay->addWidget(logo);
	lay->addWidget(title);
	lay->addWidget(set);
	lay->addWidget(min);
	lay->addWidget(max);
	lay->addWidget(close);
 
	lay->setContentsMargins(5, 5, 5,5);
}

实现无边窗口的拉伸、改变大小：

重写nativeEvent：

#include 
bool nativeEvent(const QByteArray& eventType, void* message, long* result) override;
 
bool QtWidgetsApplication2::nativeEvent(const QByteArray & eventType, void * message, long * result)
{
	MSG* param = static_cast(message);
 
	switch (param->message)
	{
	case WM_NCHITTEST:
	{
		int nX = GET_X_LPARAM(param->lParam) - this->geometry().x();
		int nY = GET_Y_LPARAM(param->lParam) - this->geometry().y();
 
		/*if (childAt(nX, nY) != nullptr)
			return QWidget::nativeEvent(eventType, message, result);*/
 
		if (nX > m_nBorderWidth && nX < this->width() - m_nBorderWidth &&
			nY > m_nBorderWidth && nY < this->height() - m_nBorderWidth)
		{
			if (childAt(nX, nY) != nullptr)
				return QWidget::nativeEvent(eventType, message, result);
		}
 
		if ((nX > 0) && (nX < m_nBorderWidth))
			*result = HTLEFT;
 
		if ((nX > this->width() - m_nBorderWidth) && (nX < this->width()))
			*result = HTRIGHT;
 
		if ((nY > 0) && (nY < m_nBorderWidth))
			*result = HTTOP;
 
		if ((nY > this->height() - m_nBorderWidth) && (nY < this->height()))
			*result = HTBOTTOM;
 
		if ((nX > 0) && (nX < m_nBorderWidth) && (nY > 0)
			&& (nY < m_nBorderWidth))
			*result = HTTOPLEFT;
 
		if ((nX > this->width() - m_nBorderWidth) && (nX < this->width())
			&& (nY > 0) && (nY < m_nBorderWidth))
			*result = HTTOPRIGHT;
 
		if ((nX > 0) && (nX < m_nBorderWidth)
			&& (nY > this->height() - m_nBorderWidth) && (nY < this->height()))
			*result = HTBOTTOMLEFT;
 
		if ((nX > this->width() - m_nBorderWidth) && (nX < this->width())
			&& (nY > this->height() - m_nBorderWidth) && (nY < this->height()))
			*result = HTBOTTOMRIGHT;
 
		return true;
	}
	}
	return false;
}

启用鼠标悬停事件：

setAttribute(Qt::WA_Hover)