QCategoryAxis 类

QCategoryAxis 类把命名范围放置在轴上。 更多...

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

公共类型

enum AxisLabelsPosition { AxisLabelsPositionCenter, AxisLabelsPositionOnValue }

特性

公共函数

QCategoryAxis (QObject * parent = nullptr)
virtual ~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 QAbstractAxis::AxisType type () const override

信号

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

详细描述

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 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 = nullptr)

Constructs an axis object that is a child of parent .

[signal] void QCategoryAxis:: categoriesChanged ()

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

[虚拟] 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.

QStringList QCategoryAxis:: categoriesLabels ()

Returns the list of the categories' labels.

注意: Getter function for property 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 )

设置 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 function for property startValue.

另请参阅 setStartValue ().

[override virtual] QAbstractAxis::AxisType QCategoryAxis:: type () const

重实现: QValueAxis::type () const.

返回轴的类型。