QLegend 类

The QLegend class displays the legend of a chart. 更多...

头: #include <QLegend>
实例化: 图例
继承: QGraphicsWidget

公共类型

enum MarkerShape { MarkerShapeDefault, MarkerShapeRectangle, MarkerShapeCircle, MarkerShapeRotatedRectangle, MarkerShapeTriangle, …, MarkerShapeFromSeries }

特性

公共函数

virtual ~QLegend ()
Qt::Alignment alignment () const
void attachToChart ()
QColor borderColor ()
QBrush brush () const
QColor color ()
void detachFromChart ()
QFont font () const
bool isAttachedToChart ()
bool isBackgroundVisible () const
(从 6.2 起) bool isInteractive () const
QBrush labelBrush () const
QColor labelColor () const
QLegend::MarkerShape markerShape () const
QList<QLegendMarker *> markers (QAbstractSeries * series = nullptr) const
QPen pen () const
bool reverseMarkers ()
void setAlignment (Qt::Alignment alignment )
void setBackgroundVisible (bool visible = true)
void setBorderColor (QColor color )
void setBrush (const QBrush & brush )
void setColor (QColor color )
void setFont (const QFont & font )
(从 6.2 起) void setInteractive (bool interactive )
void setLabelBrush (const QBrush & brush )
void setLabelColor (QColor color )
void setMarkerShape (QLegend::MarkerShape shape )
void setPen (const QPen & pen )
void setReverseMarkers (bool reverseMarkers = true)
void setShowToolTips (bool show )
bool showToolTips () const

信号

(从 6.2 起) void attachedToChartChanged (bool attached )
void backgroundVisibleChanged (bool visible )
void borderColorChanged (QColor color )
void colorChanged (QColor color )
void fontChanged (QFont font )
void labelColorChanged (QColor color )
void markerShapeChanged (QLegend::MarkerShape shape )
void reverseMarkersChanged (bool reverseMarkers )
void showToolTipsChanged (bool showToolTips )

详细描述

A legend is a graphical object that displays the legend of a chart. The legend state is updated by QChart when series change. By default, the legend is attached to the chart, but it can be detached to make it independent of chart layout. Legend objects cannot be created or deleted, but they can be referenced via the QChart 类。

另请参阅 QChart .

成员类型文档编制

enum QLegend:: MarkerShape

This enum describes the shape used when rendering legend marker items.

常量 描述
QLegend::MarkerShapeDefault 0 Default shape determined by QLegend is used for the marker. This value is supported only for individual QLegendMarker 项。
QLegend::MarkerShapeRectangle 1 Rectangular markers are used. Marker size is determined by font size.
QLegend::MarkerShapeCircle 2 Circular markers are used. Marker size is determined by font size.
QLegend::MarkerShapeRotatedRectangle 4 Rotated rectangle shaped markers are used. Marker size is determined by font size.
QLegend::MarkerShapeTriangle 5 Triangular markers are used. Marker size is determined by font size.
QLegend::MarkerShapeStar 6 Star shaped markers are used. Marker size is determined by font size.
QLegend::MarkerShapePentagon 7 Pentagon shaped markers are used. Marker size is determined by font size.
QLegend::MarkerShapeFromSeries 3 The marker shape is determined by the series. In case of a scatter series, the legend marker looks like a scatter dot and is the same size as the dot. In case of a line or spline series, the legend marker looks like a small segment of the line. For other series types, rectangular markers are shown. If a lightMarker is specified for a series, the lightMarker will be shown and its size will be determined by the series marker size.

另请参阅 markerShape .

特性文档编制

alignment : Qt::Alignment

How the legend is aligned with the chart.

可以是 Qt::AlignTop , Qt::AlignBottom , Qt::AlignLeft , Qt::AlignRight . If you set more than one flag, the result is undefined.

访问函数:

Qt::Alignment alignment () const
void setAlignment (Qt::Alignment alignment )

backgroundVisible : bool

This property holds whether the legend background is visible.

访问函数:

bool isBackgroundVisible () const
void setBackgroundVisible (bool visible = true)

通知程序信号:

void backgroundVisibleChanged (bool visible )

borderColor : QColor

This property holds the line color of the legend.

访问函数:

QColor borderColor ()
void setBorderColor (QColor color )

通知程序信号:

void borderColorChanged (QColor color )

color : QColor

This property holds the background (brush) color of the legend.

If you change the color of the legend, the style of the legend brush is set to Qt::SolidPattern .

访问函数:

QColor color ()
void setColor (QColor color )

通知程序信号:

void colorChanged (QColor color )

font : QFont

This property holds the font of the markers used by the legend.

访问函数:

QFont font () const
void setFont (const QFont & font )

通知程序信号:

void fontChanged (QFont font )

labelColor : QColor

This property holds the color of the brush used to draw labels.

访问函数:

QColor labelColor () const
void setLabelColor (QColor color )

通知程序信号:

void labelColorChanged (QColor color )

markerShape : MarkerShape

The default shape of the legend markers. The default value is MarkerShapeRectangle .

访问函数:

QLegend::MarkerShape markerShape () const
void setMarkerShape (QLegend::MarkerShape shape )

通知程序信号:

void markerShapeChanged (QLegend::MarkerShape shape )

reverseMarkers : bool

This property holds whether reverse order is used for the markers in the legend.

此特性是 false 在默认情况下。

访问函数:

bool reverseMarkers ()
void setReverseMarkers (bool reverseMarkers = true)

通知程序信号:

void reverseMarkersChanged (bool reverseMarkers )

showToolTips : bool

This property holds whether tooltips are shown when the text is truncated.

此特性是 false 在默认情况下。

访问函数:

bool showToolTips () const
void setShowToolTips (bool show )

通知程序信号:

void showToolTipsChanged (bool showToolTips )

成员函数文档编制

[virtual noexcept] QLegend:: ~QLegend ()

Destroys the legend object. The legend is always owned by a QChart , so an application should never call this function.

void QLegend:: attachToChart ()

Attaches the legend to a chart. The chart may adjust the layout of the legend.

[signal, since 6.2] void QLegend:: attachedToChartChanged ( bool attached )

This signal is emitted when the legend is attached to or detached from the chart.

该函数在 Qt 6.2 引入。

[signal] void QLegend:: backgroundVisibleChanged ( bool visible )

This signal is emitted when the visibility of the legend background changes to visible .

注意: 通知程序信号对于特性 backgroundVisible .

[signal] void QLegend:: borderColorChanged ( QColor color )

This signal is emitted when the border color of the legend background changes to color .

注意: 通知程序信号对于特性 borderColor .

QBrush QLegend:: brush () const

Returns the brush used by the legend.

另请参阅 setBrush ().

[signal] void QLegend:: colorChanged ( QColor color )

This signal is emitted when the color of the legend background changes to color .

注意: 通知程序信号对于特性 color .

void QLegend:: detachFromChart ()

Detaches the legend from the chart. The chart will no longer adjust the layout of the legend.

[signal] void QLegend:: fontChanged ( QFont font )

This signal is emitted when the font of the markers of the legend changes to font .

注意: 通知程序信号对于特性 font .

bool QLegend:: isAttachedToChart ()

返回 true , if the legend is attached to a chart.

bool QLegend:: isBackgroundVisible () const

Returns the visibility of the legend background.

注意: getter 函数对于特性 backgroundVisible .

[since 6.2] bool QLegend:: isInteractive () const

Returns whether the legend can be dragged or resized using a mouse when it is detached.

该函数在 Qt 6.2 引入。

另请参阅 QLegend::setInteractive ().

QBrush QLegend:: labelBrush () const

Returns the brush used to draw labels.

另请参阅 setLabelBrush ().

[signal] void QLegend:: labelColorChanged ( QColor color )

This signal is emitted when the color of the brush used to draw the legend labels changes to color .

注意: 通知程序信号对于特性 labelColor .

QList < QLegendMarker *> QLegend:: markers ( QAbstractSeries * series = nullptr) const

Returns the list of markers in the legend. The list can be filtered by specifying the series for which the markers are returned.

QPen QLegend:: pen () const

Returns the pen used by the legend.

另请参阅 setPen ().

[signal] void QLegend:: reverseMarkersChanged ( bool reverseMarkers )

This signal is emitted when the use of reverse order for the markers in the legend is changed to reverseMarkers .

注意: 通知程序信号对于特性 reverseMarkers .

void QLegend:: setBackgroundVisible ( bool visible = true)

Sets the visibility of the legend background to visible .

注意: setter 函数对于特性 backgroundVisible .

另请参阅 isBackgroundVisible ().

void QLegend:: setBrush (const QBrush & brush )

设置 brush that is used to draw the background of the legend.

另请参阅 brush ().

[since 6.2] void QLegend:: setInteractive ( bool interactive )

interactive is true and the legend is detached, the legend is able to be moved and resized with a mouse in a similar way to a window.

The legend will automatically attach to an edge of the chart by dragging it off of that edge. Double clicking an attached legend will detach it. This is false 在默认情况下。

该函数在 Qt 6.2 引入。

另请参阅 QLegend::isInteractive ().

void QLegend:: setLabelBrush (const QBrush & brush )

Sets the brush used to draw the legend labels to brush .

另请参阅 labelBrush ().

void QLegend:: setPen (const QPen & pen )

设置 pen that is used to draw the legend borders.

另请参阅 pen ().

void QLegend:: setShowToolTips ( bool show )

show is true , the legend labels will show a tooltip when the mouse hovers over them if the label itself is shown elided. This is false 在默认情况下。

注意: setter 函数对于特性 showToolTips .

另请参阅 showToolTips ().

bool QLegend:: showToolTips () const

Returns whether the tooltips are shown for the legend labels when they are elided.

注意: Getter function for property showToolTips.

另请参阅 setShowToolTips ().

[signal] void QLegend:: showToolTipsChanged ( bool showToolTips )

This signal is emitted when the visibility of tooltips is changed to showToolTips .

注意: 通知程序信号对于特性 showToolTips .