QStackedWidget 类

QStackedWidget 类提供每次仅一 Widget 可见的小部件堆栈。 更多...

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

特性

公共函数

QStackedWidget (QWidget * parent = nullptr)
virtual ~QStackedWidget ()
int addWidget (QWidget * widget )
int count () const
int currentIndex () const
QWidget * currentWidget () const
int indexOf (const QWidget * widget ) const
int insertWidget (int index , QWidget * widget )
void removeWidget (QWidget * widget )
QWidget * widget (int index ) const

公共槽

void setCurrentIndex (int index )
void setCurrentWidget (QWidget * widget )

信号

void currentChanged (int index )
void widgetRemoved (int index )

重实现保护函数

virtual bool event (QEvent * e ) override

详细描述

QStackedWidget can be used to create a user interface similar to the one provided by QTabWidget . It is a convenience layout widget built on top of the QStackedLayout 类。

QStackedLayout , QStackedWidget can be constructed and populated with a number of child widgets ("pages"):

    QWidget *firstPageWidget = new QWidget;
    QWidget *secondPageWidget = new QWidget;
    QWidget *thirdPageWidget = new QWidget;
    QStackedWidget *stackedWidget = new QStackedWidget;
    stackedWidget->addWidget(firstPageWidget);
    stackedWidget->addWidget(secondPageWidget);
    stackedWidget->addWidget(thirdPageWidget);
    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(stackedWidget);
    setLayout(layout);
					

QStackedWidget provides no intrinsic means for the user to switch page. This is typically done through a QComboBox QListWidget that stores the titles of the QStackedWidget's pages. For example:

    QComboBox *pageComboBox = new QComboBox;
    pageComboBox->addItem(tr("Page 1"));
    pageComboBox->addItem(tr("Page 2"));
    pageComboBox->addItem(tr("Page 3"));
    connect(pageComboBox, &QComboBox::activated,
            stackedWidget, &QStackedWidget::setCurrentIndex);
					

When populating a stacked widget, the widgets are added to an internal list. The indexOf () function returns the index of a widget in that list. The widgets can either be added to the end of the list using the addWidget () function, or inserted at a given index using the insertWidget () 函数。 removeWidget () function removes a widget from the stacked widget. The number of widgets contained in the stacked widget can be obtained using the count () 函数。

The widget () function returns the widget at a given index position. The index of the widget that is shown on screen is given by currentIndex () and can be changed using setCurrentIndex (). In a similar manner, the currently shown widget can be retrieved using the currentWidget () 函数,和变更使用 setCurrentWidget () 函数。

Whenever the current widget in the stacked widget changes or a widget is removed from the stacked widget, the currentChanged () 和 widgetRemoved () signals are emitted respectively.

另请参阅 QStackedLayout and QTabWidget .

特性文档编制

[read-only] count : const int

This property holds the number of widgets contained by this stacked widget

默认情况下,此特性包含 0 值。

访问函数:

int count () const

另请参阅 currentIndex () 和 widget ().

currentIndex : int

此特性保持可见 Widget 的索引位置

当前索引为 -1,若没有当前 Widget。

By default, this property contains a value of -1 because the stack is initially empty.

访问函数:

int currentIndex () const
void setCurrentIndex (int index )

通知程序信号:

void currentChanged (int index )

另请参阅 currentWidget () 和 indexOf ().

成员函数文档编制

[explicit] QStackedWidget:: QStackedWidget ( QWidget * parent = nullptr)

Constructs a QStackedWidget with the given parent .

另请参阅 addWidget () 和 insertWidget ().

[virtual noexcept] QStackedWidget:: ~QStackedWidget ()

Destroys this stacked widget, and frees any allocated resources.

int QStackedWidget:: addWidget ( QWidget * widget )

Appends the given widget QStackedWidget and returns the index position. Ownership of widget 被传递给 QStackedWidget .

QStackedWidget is empty before this function is called, widget becomes the current widget.

另请参阅 insertWidget (), removeWidget (),和 setCurrentWidget ().

[signal] void QStackedWidget:: currentChanged ( int index )

This signal is emitted whenever the current widget changes.

The parameter holds the index of the new current widget, or -1 if there isn't a new one (for example, if there are no widgets in the QStackedWidget ).

注意: 通知程序信号对于特性 currentIndex .

另请参阅 currentWidget () 和 setCurrentWidget ().

QWidget *QStackedWidget:: currentWidget () const

返回当前 Widget,或 nullptr 若没有子级 Widget。

另请参阅 currentIndex () 和 setCurrentWidget ().

[override virtual protected] bool QStackedWidget:: event ( QEvent * e )

重实现: QFrame::event (QEvent *e).

int QStackedWidget:: indexOf (const QWidget * widget ) const

返回索引为给定 widget , or -1 if the given widget is not a child of the QStackedWidget .

另请参阅 currentIndex () 和 widget ().

int QStackedWidget:: insertWidget ( int index , QWidget * widget )

插入给定 widget 在给定 index QStackedWidget . Ownership of widget 被传递给 QStackedWidget 。若 index is out of range, the widget is appended (in which case it is the actual index of the widget that is returned).

QStackedWidget was empty before this function is called, the given widget becomes the current widget.

Inserting a new widget at an index less than or equal to the current index will increment the current index, but keep the current widget.

另请参阅 addWidget (), removeWidget (),和 setCurrentWidget ().

void QStackedWidget:: removeWidget ( QWidget * widget )

移除 widget QStackedWidget . i.e., widget is not deleted but simply removed from the stacked layout, causing it to be hidden.

注意: Parent object and parent widget of widget will remain the QStackedWidget . If the application wants to reuse the removed widget , then it is recommended to re-parent it.

另请参阅 addWidget (), insertWidget (),和 currentWidget ().

[slot] void QStackedWidget:: setCurrentWidget ( QWidget * widget )

Sets the current widget to be the specified widget . The new current widget must already be contained in this stacked widget.

另请参阅 currentWidget () 和 setCurrentIndex ().

QWidget *QStackedWidget:: widget ( int index ) const

返回 Widget 在给定 index ,或 nullptr 若没有这种 Widget。

另请参阅 currentWidget () 和 indexOf ().

[signal] void QStackedWidget:: widgetRemoved ( int index )

This signal is emitted whenever a widget is removed. The widget's index is passed as parameter.

另请参阅 removeWidget ().