QStackedWidget 类提供每次仅一 Widget 可见的 Widget 堆栈。 更多...
| 头： | #include <QStackedWidget> |
| qmake: | QT += widgets |
| 继承： | QFrame |
| QStackedWidget (QWidget * parent = nullptr) | |
| virtual | ~QStackedWidget () |
| int | addWidget (QWidget * widget ) |
| int | count () const |
| int | currentIndex () const |
| QWidget * | currentWidget () const |
| int | indexOf (QWidget * widget ) const |
| int | insertWidget (int index , QWidget * widget ) |
| void | removeWidget (QWidget * widget ) |
| QWidget * | widget (int index ) const |
| void | setCurrentIndex (int index ) |
| void | setCurrentWidget (QWidget * widget ) |
| void | currentChanged (int index ) |
| void | widgetRemoved (int index ) |
| virtual bool | event (QEvent * e ) override |
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。
像 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 或 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, QOverload<int>::of(&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。
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 .
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 ().
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 ().
Constructs a QStackedWidget with the given parent .
另请参阅 addWidget () 和 insertWidget ().
[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 ().
[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 ().
[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 ().
[virtual]
QStackedWidget::
~QStackedWidget
()
Destroys this stacked widget, and frees any allocated resources.
Appends the given widget 到 QStackedWidget and returns the index position. Ownership of widget 被传递给 QStackedWidget .
若 QStackedWidget is empty before this function is called, widget becomes the current widget.
另请参阅 insertWidget (), removeWidget ()，和 setCurrentWidget ().
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).
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 ().
插入给定 widget 在给定 index 在 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).
若 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 ().
移除 widget 从 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 ().
返回 Widget 在给定
index
，或
nullptr
若没有这样的 Widget。
另请参阅 currentWidget () 和 indexOf ().