QSpacerItem 类

QSpacerItem 类在布局中提供空白空间。更多...

头：	#include <QSpacerItem>
CMake:	find_package(Qt6 REQUIRED COMPONENTS Widgets) target_link_libraries(mytarget PRIVATE Qt6::Widgets)
qmake:	QT += widgets
继承：	QLayoutItem

所有成员列表，包括继承成员

公共函数

	QSpacerItem (int w , int h , QSizePolicy::Policy hPolicy = QSizePolicy::Minimum, QSizePolicy::Policy vPolicy = QSizePolicy::Minimum)
virtual	~QSpacerItem ()
void	changeSize (int w , int h , QSizePolicy::Policy hPolicy = QSizePolicy::Minimum, QSizePolicy::Policy vPolicy = QSizePolicy::Minimum)
QSizePolicy	sizePolicy () const

重实现公共函数

virtual Qt::Orientations	expandingDirections () const override
virtual QRect	geometry () const override
virtual bool	isEmpty () const override
virtual QSize	maximumSize () const override
virtual QSize	minimumSize () const override
virtual void	setGeometry (const QRect & r ) override
virtual QSize	sizeHint () const override
virtual QSpacerItem *	spacerItem () override

详细描述

Normally, you don't need to use this class directly. Qt's built-in layout managers provide the following functions for manipulating empty space in layouts:

类	函数
QHBoxLayout	addSpacing (), addStretch (), insertSpacing (), insertStretch ()
QGridLayout	setRowMinimumHeight (), setRowStretch (), setColumnMinimumWidth (), setColumnStretch ()

另请参阅 QLayout , QWidgetItem ，和 QLayoutItem::spacerItem ().

成员函数文档编制

QSpacerItem:: QSpacerItem ( int w , int h , QSizePolicy::Policy hPolicy = QSizePolicy::Minimum, QSizePolicy::Policy vPolicy = QSizePolicy::Minimum)

Constructs a spacer item with preferred width w , preferred height h , horizontal size policy hPolicy and vertical size policy vPolicy .

The default values provide a gap that is able to stretch if nothing else wants the space.

`[virtual noexcept]` QSpacerItem:: ~QSpacerItem ()

析构函数。

void QSpacerItem:: changeSize ( int w , int h , QSizePolicy::Policy hPolicy = QSizePolicy::Minimum, QSizePolicy::Policy vPolicy = QSizePolicy::Minimum)

Changes this spacer item to have preferred width w , preferred height h , horizontal size policy hPolicy and vertical size policy vPolicy .

The default values provide a gap that is able to stretch if nothing else wants the space.

Note that if changeSize() is called after the spacer item has been added to a layout, it is necessary to invalidate the layout in order for the spacer item's new size to take effect.

另请参阅 QSpacerItem::invalidate ().