Qt代码实现layout布局且窗口拉伸具有自动排版功能

1，为了方便大家复制，直接上代码，如果有人能用上了，记得点赞转发。首先重载布局

重载layout

（1）customproxy.cpp

#include "customproxy.h"

#include 

CustomProxy::CustomProxy(QGraphicsItem *parent, Qt::WindowFlags wFlags)
: QGraphicsProxyWidget(parent, wFlags), popupShown(false), currentPopup(0)
{
timeLine = new QTimeLine(250, this);
/*connect(timeLine, SIGNAL(valueChanged(qreal)),
this, SLOT(updateStep(qreal)));*/
//connect(timeLine, SIGNAL(stateChanged(QTimeLine::State)),
// this, SLOT(stateChanged(QTimeLine::State)));
}

QRectF CustomProxy::boundingRect() const
{
return QGraphicsProxyWidget::boundingRect().adjusted(0, 0, 10, 10);
}

void CustomProxy::paintWindowFrame(QPainter *painter, const QStyleOptionGraphicsItem *option,
QWidget *widget)
{
const QColor color(0, 0, 0, 64);
QRectF r = windowFrameRect();
QRectF right(r.right(), r.top() + 10, 10, r.height() - 10);
QRectF bottom(r.left() + 10, r.bottom(), r.width(), 10);
bool intersectsRight = right.intersects(option->exposedRect);
bool intersectsBottom = bottom.intersects(option->exposedRect);
if (intersectsRight && intersectsBottom) {
QPainterPath path;
path.addRect(right);
path.addRect(bottom);
painter->setPen(Qt::NoPen);
painter->setBrush(color);
painter->drawPath(path);
} else if (intersectsBottom) {
painter->fillRect(bottom, color);
} else if (intersectsRight) {
painter->fillRect(right, color);
}


QGraphicsProxyWidget::paintWindowFrame(painter, option, widget);
}
/*鼠标移动事件，放上去*/
void 
CustomProxy::hoverEnterEvent(QGraphicsSceneHoverEvent *event)
{

QGraphicsProxyWidget::hoverEnterEvent(event);
scene()->setActiveWindow(this);
if (timeLine->currentValue() != 1)
zoomIn();
}
/*鼠标移动事件，离开*/
void 
CustomProxy::hoverLeaveEvent(QGraphicsSceneHoverEvent *event)
{

QGraphicsProxyWidget::hoverLeaveEvent(event);
if (!popupShown && (timeLine->direction() != QTimeLine::Backward || timeLine->currentValue() != 0))
zoomOut();
}

bool CustomProxy::sceneEventFilter(QGraphicsItem *watched, QEvent *event)
{
if (watched->isWindow() && (event->type() == QEvent::UngrabMouse || event->type() == QEvent::GrabMouse)) {
popupShown = watched->isVisible();
if (!popupShown && !isUnderMouse())
zoomOut();
}
return QGraphicsProxyWidget::sceneEventFilter(watched, event);
}

QVariant CustomProxy::itemChange(GraphicsItemChange change, const QVariant &value)
{
if (change == ItemChildAddedChange || change == ItemChildRemovedChange) {
if (change == ItemChildAddedChange) {
currentPopup = qVariantValue(value);
currentPopup->setCacheMode(ItemCoordinateCache);
if (scene())
currentPopup->installSceneEventFilter(this);
} else if (scene()) {
currentPopup->removeSceneEventFilter(this);
currentPopup = 0;
}
} else if (currentPopup && change == ItemSceneHasChanged) {
currentPopup->installSceneEventFilter(this);
}
return QGraphicsProxyWidget::itemChange(change, value);
}

void CustomProxy::updateStep(qreal step)
{
QRectF r = boundingRect();
setTransform(QTransform().translate(r.width() / 2, r.height() / 2)
.rotate(step * 30, Qt::XAxis).rotate(step * 10, Qt::YAxis)
.rotate(step * 5, Qt::ZAxis).scale(1 + 1.5 * step, 1 + 1.5 * step)
.translate(-r.width() / 2, -r.height() / 2));
}

void CustomProxy::stateChanged(QTimeLine::State state)
{
if (state == QTimeLine::Running) {
if (timeLine->direction() == QTimeLine::Forward)
setCacheMode(ItemCoordinateCache);
} else if (state == QTimeLine::NotRunning) {
if (timeLine->direction() == QTimeLine::Backward)
setCacheMode(DeviceCoordinateCache);
}
}

void CustomProxy::zoomIn()
{
if (timeLine->direction() != QTimeLine::Forward)
timeLine->setDirection(QTimeLine::Forward);
if (timeLine->state() == QTimeLine::NotRunning)
timeLine->start();
}

void CustomProxy::zoomOut()
{
if (timeLine->direction() != QTimeLine::Backward)
timeLine->setDirection(QTimeLine::Backward);
if (timeLine->state() == QTimeLine::NotRunning)
timeLine->start();
}

void CustomProxy::mouseReleaseEvent( QGraphicsSceneMouseEvent * )
{
setPos(m_OrgPoint.x(),m_OrgPoint.y());

}

(2),customproxy.h

#ifndef CUSTOMPROXY_H
#define CUSTOMPROXY_H

#include 
#include 

class CustomProxy : public QGraphicsProxyWidget
{
Q_OBJECT
public:
CustomProxy(QGraphicsItem *parent = 0, Qt::WindowFlags wFlags = 0);

QRectF boundingRect() const;
void paintWindowFrame(QPainter *painter, const QStyleOptionGraphicsItem *option,
QWidget *widget);

protected:
void hoverEnterEvent(QGraphicsSceneHoverEvent *event);
void hoverLeaveEvent(QGraphicsSceneHoverEvent *event);
bool sceneEventFilter(QGraphicsItem *watched, QEvent *event);
QVariant itemChange(GraphicsItemChange change, const QVariant &value);
void mouseReleaseEvent ( QGraphicsSceneMouseEvent * );

private slots:
void updateStep(qreal step);
void stateChanged(QTimeLine::State);
void zoomIn();
void zoomOut();

private:
QTimeLine *timeLine;
bool popupShown;
QGraphicsItem *currentPopup;
public:
QPoint m_OrgPoint;

};

#endif

2，把所需要的窗体或控件放到入到m_layout中,并把主窗体的布局通过setLayout设上去。
运行程序，拉伸或缩小主窗体，控件可以实现自动排版本，但缩小到一定程序无滚动条。
3，加滚动条
.............
..........
m_flowLayout = new FlowLayout();
m_scrollArea = new QScrollArea(ui->page_222);
m_scrollArea->setWidgetResizable(true);
m_scrollArea->setMinimumSize(195,400);
.........................
之后运行并不产生滚动条。

4，解决无滚动条问题
m_flowLayout = new FlowLayout();
m_scrollArea = new QScrollArea(ui->page_222);
m_scrollArea->setWidgetResizable(true);
m_scrollArea->setMinimumSize(195,400);
m_scrollArea->setWidget(ui->widget);//必须向滚动条上加个窗体

因为是记录很久的文档，暂时没有效果图，这里只是把文档移到这个平台上