内容

• 公共类型
• 特性
• 公共函数
• 重实现公共函数
• 信号
• 详细描述

QCategoryAxis 类

The QCategoryAxis class places named ranges on the axis. 更多...

头：	#include <QCategoryAxis>
实例化：	CategoryAxis
继承：	QValueAxis

• 所有成员列表，包括继承成员

公共类型

enum	AxisLabelsPosition { AxisLabelsPositionCenter, AxisLabelsPositionOnValue }

特性

• categoriesLabels : const QStringList
• count : const int
• labelsPosition : AxisLabelsPosition
• startValue : qreal

• 5 特性继承自 QValueAxis
• 27 特性继承自 QAbstractAxis
• 1 特性继承自 QObject

公共函数

	QCategoryAxis (QObject * parent = Q_NULLPTR)
	~QCategoryAxis ()
void	append (const QString & categoryLabel , qreal categoryEndValue )
QStringList	categoriesLabels ()
int	count () const
qreal	endValue (const QString & categoryLabel ) const
QCategoryAxis::AxisLabelsPosition	labelsPosition () const
void	remove (const QString & categoryLabel )
void	replaceLabel (const QString & oldLabel , const QString & newLabel )
void	setLabelsPosition (QCategoryAxis::AxisLabelsPosition position )
void	setStartValue (qreal min )
qreal	startValue (const QString & categoryLabel = QString()) const

重实现公共函数

virtual AxisType

type () const

• 12 公共函数继承自 QValueAxis
• 58 公共函数继承自 QAbstractAxis
• 32 公共函数继承自 QObject

信号

void	categoriesChanged ()
void	labelsPositionChanged (QCategoryAxis::AxisLabelsPosition position )

• 6 信号继承自 QValueAxis
• 25 信号继承自 QAbstractAxis
• 2 信号继承自 QObject

额外继承成员

• 1 公共槽继承自 QValueAxis
• 1 公共槽继承自 QObject
• 11 静态公共成员继承自 QObject
• 9 保护函数继承自 QObject

详细描述

The QCategoryAxis class places named ranges on the axis.

This class can be used to explain the underlying data by adding labeled categories. Unlike QBarCategoryAxis , QCategoryAxis allows the widths of the category ranges to be specified freely.

Example code on how to use QCategoryAxis :

QChartView *chartView = new QChartView;
QLineSeries *series = new QLineSeries;
// ...
chartView->chart()->addSeries(series);
QCategoryAxis *axisY = new QCategoryAxis;
axisY->setMin(0);
axisY->setMax(52);
axisY->setStartValue(15);
axisY->append("First", 20);
axisY->append("Second", 37);
axisY->append("Third", 52);
chartView->chart()->setAxisY(axisY, series);
					

成员类型文档编制

enum QCategoryAxis:: AxisLabelsPosition

此枚举描述类别标签的位置。

常量	值	描述
QCategoryAxis::AxisLabelsPositionCenter	0x0	Labels are centered to category.
QCategoryAxis::AxisLabelsPositionOnValue	0x1	Labels are positioned to the high end limit of the category.

特性文档编制

categoriesLabels : const QStringList

此特性以字符串列表保持类别标签。

访问函数：

QStringList

categoriesLabels ()

count : const int

此特性保持类别数。

访问函数：

int	count () const

labelsPosition : AxisLabelsPosition

This property holds the position of the category labels. The labels in the beginning and in the end of the axes may overlap other axes' labels when positioned on value.

访问函数：

QCategoryAxis::AxisLabelsPosition	labelsPosition () const
void	setLabelsPosition (QCategoryAxis::AxisLabelsPosition position )

通知程序信号：

void	labelsPositionChanged (QCategoryAxis::AxisLabelsPosition position )

startValue : qreal

This property holds the low end of the first category on the axis.

访问函数：

qreal	startValue (const QString & categoryLabel = QString()) const
void	setStartValue (qreal min )

成员函数文档编制

QCategoryAxis:: QCategoryAxis ( QObject * parent = Q_NULLPTR)

Constructs an axis object that is a child of parent .

QCategoryAxis:: ~QCategoryAxis ()

销毁对象。

void QCategoryAxis:: append (const QString & categoryLabel , qreal categoryEndValue )

Appends a new category to the axis with the label categoryLabel . A category label has to be unique. categoryEndValue specifies the high end limit of the category. It has to be greater than the high end limit of the previous category. Otherwise the method returns without adding a new category.

[signal] void QCategoryAxis:: categoriesChanged ()

This signal is emitted when the categories of the axis change.

QStringList QCategoryAxis:: categoriesLabels ()

Returns the list of the categories' labels.

注意： Getter 函数对于特性 categoriesLabels .

int QCategoryAxis:: count () const

Returns the number of categories.

注意： Getter 函数对于特性 count .

qreal QCategoryAxis:: endValue (const QString & categoryLabel ) const

Returns the high end limit of the category specified by categoryLabel .

void QCategoryAxis:: remove (const QString & categoryLabel )

Removes a category specified by the label categoryLabel from the axis.

void QCategoryAxis:: replaceLabel (const QString & oldLabel , const QString & newLabel )

Replaces an existing category label specified by oldLabel with newLabel . If the old label does not exist, the method returns without making any changes.

void QCategoryAxis:: setStartValue ( qreal min )

集 min to be the low end limit of the first category on the axis. If categories have already been added to the axis, the passed value must be less than the high end value of the already defined first category range. Otherwise nothing is done.

注意： Setter 函数对于特性 startValue .

另请参阅 startValue ().

qreal QCategoryAxis:: startValue (const QString & categoryLabel = QString()) const

Returns the low end limit of the category specified by categoryLabel .

注意： Getter 函数对于特性 startValue .

另请参阅 setStartValue ().

[虚拟] AxisType QCategoryAxis:: type () const

重实现自 QAbstractAxis::type ().

返回轴的类型。