QPen ¶

QPen class defines how a QPainter 绘制线条和形状的轮廓。更多 …

概要 ¶

函数 ¶

def __eq__ (p)
def __ne__ (p)
def brush ()
def capStyle ()
def color ()
def dashOffset ()
def dashPattern ()
def isCosmetic ()
def isSolid ()
def joinStyle ()
def miterLimit ()
def setBrush (brush)
def setCapStyle (pcs)
def setColor (color)
def setCosmetic (cosmetic)
def setDashOffset (doffset)
def setDashPattern (pattern)
def setJoinStyle (pcs)
def setMiterLimit (limit)
def setStyle (arg__1)
def setWidth (width)
def setWidthF (width)
def style ()
def swap (other)
def width ()
def widthF ()

详细描述 ¶

A pen has a style() , width() , brush() , capStyle() and joinStyle() .

The pen style defines the line type. The brush is used to fill strokes generated with the pen. Use the QBrush class to specify fill styles. The cap style determines the line end caps that can be drawn using QPainter , while the join style describes how joins between two lines are drawn. The pen width can be specified in both integer ( width() ) and floating point ( widthF() ) precision. A line width of zero indicates a cosmetic pen. This means that the pen width is always drawn one pixel wide, independent of the transformation set on the painter.

The various settings can easily be modified using the corresponding setStyle() , setWidth() , setBrush() , setCapStyle() and setJoinStyle() functions (note that the painter’s pen must be reset when altering the pen’s properties).

例如：
painter = QPainter(self)
pen = QPen(Qt.green, 3, Qt.DashDotLine, Qt.RoundCap, Qt.RoundJoin)
painter.setPen(pen)
											
which is equivalent to
painter = QPainter(self)
pen = QPen()  # creates a default pen
pen.setStyle(Qt.DashDotLine)
pen.setWidth(3)
pen.setBrush(Qt.green)
pen.setCapStyle(Qt.RoundCap)
pen.setJoinStyle(Qt.RoundJoin)
painter.setPen(pen)
											
The default pen is a solid black brush with 1 width, square cap style ( SquareCap ), and bevel join style ( BevelJoin ).

In addition QPen provides the color() and setColor() convenience functions to extract and set the color of the pen’s brush, respectively. Pens may also be compared and streamed.

For more information about painting in general, see the 描绘系统文档编制。

Pen Style ¶

Qt provides several built-in styles represented by the PenStyle enum:

SolidLine

DashLine

DotLine

DashDotLine

DashDotDotLine

CustomDashLine

Simply use the setStyle() function to convert the pen style to either of the built-in styles, except the CustomDashLine style which we will come back to shortly. Setting the style to NoPen tells the painter to not draw lines or outlines. The default pen style is SolidLine .

Since Qt 4.1 it is also possible to specify a custom dash pattern using the setDashPattern() function which implicitly converts the style of the pen to CustomDashLine . The pattern argument, a QVector , must be specified as an even number of qreal entries where the entries 1, 3, 5… are the dashes and 2, 4, 6… are the spaces. For example, the custom pattern shown above is created using the following code:
pen = QPen()
space = 4;
dashes = [1, space, 3, space, 9, space, 27, space, 9, space]
pen.setDashPattern(dashes)
												
Note that the dash pattern is specified in units of the pens width, e.g. a dash of length 5 in width 10 is 50 pixels long.

The currently set dash pattern can be retrieved using the dashPattern() function. Use the isSolid() function to determine whether the pen has a solid fill, or not.

Cap Style ¶

The cap style defines how the end points of lines are drawn using QPainter . The cap style only apply to wide lines, i.e. when the width is 1 or greater. The PenCapStyle enum provides the following styles:

SquareCap

FlatCap

RoundCap

SquareCap style is a square line end that covers the end point and extends beyond it by half the line width. The FlatCap style is a square line end that does not cover the end point of the line. And the RoundCap style is a rounded line end covering the end point.

默认为 SquareCap .

Whether or not end points are drawn when the pen width is 0 or 1 depends on the cap style. Using SquareCap or RoundCap they are drawn, using FlatCap they are not drawn.

Join Style ¶

The join style defines how joins between two connected lines can be drawn using QPainter . The join style only apply to wide lines, i.e. when the width is 1 or greater. The PenJoinStyle enum provides the following styles:

BevelJoin

MiterJoin

RoundJoin

BevelJoin style fills the triangular notch between the two lines. The MiterJoin style extends the lines to meet at an angle. And the RoundJoin style fills a circular arc between the two lines.

默认为 BevelJoin .

当 MiterJoin style is applied, it is possible to use the setMiterLimit() function to specify how far the miter join can extend from the join point. The miterLimit() is used to reduce artifacts between line joins where the lines are close to parallel.

miterLimit() must be specified in units of the pens width, e.g. a miter limit of 5 in width 10 is 50 pixels long. The default miter limit is 2, i.e. twice the pen width in pixels.

** ** The Path Stroking Example ** **

The Path Stroking example shows Qt’s built-in dash patterns and shows how custom patterns can be used to extend the range of available patterns.

另请参阅

QPainter QBrush Path Stroking Example 涂鸦范例

class QPen ¶

QPen(arg__1)

QPen(brush, width[, s=Qt.SolidLine[, c=Qt.SquareCap[, j=Qt.BevelJoin]]])

QPen(color)

QPen(pen)

param j

PenJoinStyle

param arg__1

PenStyle

param brush

QBrush

param color

QColor

param s

PenStyle

param width

qreal

param c

PenCapStyle

param pen

QPen

构造默认黑色实线钢笔采用 1 宽度。

构造黑色钢笔采用 1 宽度和给定 style .

另请参阅

setStyle()

构造钢笔采用指定 brush , width , pen style , cap style and join style.

另请参阅

setBrush() setWidth() setStyle() setCapStyle() setJoinStyle()

PySide2.QtGui.QPen. brush ( ) ¶

返回类型: QBrush

Returns the brush used to fill strokes generated with this pen.

另请参阅

setBrush()

PySide2.QtGui.QPen. capStyle ( ) ¶

返回类型: PenCapStyle

Returns the pen’s cap style.

另请参阅

setCapStyle() Cap Style

PySide2.QtGui.QPen. color ( ) ¶

返回类型: QColor

Returns the color of this pen’s brush.

另请参阅

brush() setColor()

PySide2.QtGui.QPen. dashOffset ( ) ¶

返回类型: qreal

返回钢笔的虚线偏移。

另请参阅

setDashOffset()

PySide2.QtGui.QPen. dashPattern ( ) ¶

返回类型

返回此钢笔的虚线图案。

另请参阅

setDashPattern() style() isSolid()

PySide2.QtGui.QPen. isCosmetic ( ) ¶

返回类型: bool

返回 true if the pen is cosmetic; otherwise returns false .

Cosmetic pens are used to draw strokes that have a constant width regardless of any transformations applied to the QPainter they are used with. Drawing a shape with a cosmetic pen ensures that its outline will have the same thickness at different scale factors.

A zero width pen is cosmetic by default.

另请参阅

setCosmetic() widthF()

PySide2.QtGui.QPen. isSolid ( ) ¶

返回类型: bool

返回 true if the pen has a solid fill, otherwise false.

另请参阅

style() dashPattern()

PySide2.QtGui.QPen. joinStyle ( ) ¶

返回类型: PenJoinStyle

Returns the pen’s join style.

另请参阅

setJoinStyle() Join Style

PySide2.QtGui.QPen. miterLimit ( ) ¶

返回类型: qreal

Returns the miter limit of the pen. The miter limit is only relevant when the join style is set to MiterJoin .

另请参阅

setMiterLimit() Join Style

PySide2.QtGui.QPen. __ne__ ( p ) ¶

参数: p – QPen
返回类型: bool

返回 true if the pen is different from the given pen ; otherwise false. Two pens are different if they have different styles, widths or colors.

另请参阅

operator==()

PySide2.QtGui.QPen. __eq__ ( p ) ¶

参数: p – QPen
返回类型: bool

返回 true if the pen is equal to the given pen ; otherwise false. Two pens are equal if they have equal styles, widths and colors.

另请参阅

operator!=()

PySide2.QtGui.QPen. setBrush ( brush ) ¶

参数: brush – QBrush

Sets the brush used to fill strokes generated with this pen to the given brush .

另请参阅

brush() setColor()

PySide2.QtGui.QPen. setCapStyle ( pcs ) ¶

参数: pcs – PenCapStyle

Sets the pen’s cap style to the given style 。默认值为 SquareCap .

另请参阅

capStyle() Cap Style

PySide2.QtGui.QPen. setColor ( color ) ¶

参数: color – QColor

Sets the color of this pen’s brush to the given color .

另请参阅

setBrush() color()

PySide2.QtGui.QPen. setCosmetic ( cosmetic ) ¶

参数: cosmetic – bool

Sets this pen to cosmetic or non-cosmetic, depending on the value of cosmetic .

另请参阅

isCosmetic()

PySide2.QtGui.QPen. setDashOffset ( doffset ) ¶

参数: doffset – qreal

Sets the dash offset (the starting point on the dash pattern) for this pen to the offset specified. The offset is measured in terms of the units used to specify the dash pattern.

qpen-dashpattern1

For example, a pattern where each stroke is four units long, followed by a gap of two units, will begin with the stroke when drawn as a line.

However, if the dash offset is set to 4.0, any line drawn will begin with the gap. Values of the offset up to 4.0 will cause part of the stroke to be drawn first, and values of the offset between 4.0 and 6.0 will cause the line to begin with part of the gap.

注意

This implicitly converts the style of the pen to CustomDashLine .

另请参阅

dashOffset()

PySide2.QtGui.QPen. setDashPattern ( pattern ) ¶

参数: pattern –

Sets the dash pattern for this pen to the given pattern . This implicitly converts the style of the pen to CustomDashLine .

The pattern must be specified as an even number of positive entries where the entries 1, 3, 5… are the dashes and 2, 4, 6… are the spaces. For example:

qpen-custom1

																pen = QPen()
space = 4;
dashes = [1, space, 3, space, 9, space, 27, space, 9, space]
pen.setDashPattern(dashes)
																
															

The dash pattern is specified in units of the pens width; e.g. a dash of length 5 in width 10 is 50 pixels long. Note that a pen with zero width is equivalent to a cosmetic pen with a width of 1 pixel.

Each dash is also subject to cap styles so a dash of 1 with square cap set will extend 0.5 pixels out in each direction resulting in a total width of 2.

Note that the default cap style is SquareCap , meaning that a square line end covers the end point and extends beyond it by half the line width.

另请参阅

setStyle() dashPattern() setCapStyle() setCosmetic()

PySide2.QtGui.QPen. setJoinStyle ( pcs ) ¶

参数: pcs – PenJoinStyle

Sets the pen’s join style to the given style 。默认值为 BevelJoin .

另请参阅

joinStyle() Join Style

PySide2.QtGui.QPen. setMiterLimit ( limit ) ¶

参数: limit – qreal

Sets the miter limit of this pen to the given limit .

The miter limit describes how far a miter join can extend from the join point. This is used to reduce artifacts between line joins where the lines are close to parallel.

This value does only have effect when the pen style is set to MiterJoin . The value is specified in units of the pen’s width, e.g. a miter limit of 5 in width 10 is 50 pixels long. The default miter limit is 2, i.e. twice the pen width in pixels.

另请参阅

miterLimit() setJoinStyle() Join Style

PySide2.QtGui.QPen. setStyle ( arg__1 ) ¶

参数: arg__1 – PenStyle

Sets the pen style to the given style .

见 PenStyle documentation for a list of the available styles. Since Qt 4.1 it is also possible to specify a custom dash pattern using the setDashPattern() function which implicitly converts the style of the pen to CustomDashLine .

注意

This function resets the dash offset to zero.

另请参阅

style() Pen Style

PySide2.QtGui.QPen. setWidth ( width ) ¶

参数: width – int

Sets the pen width to the given width in pixels with integer precision.

A line width of zero indicates a cosmetic pen. This means that the pen width is always drawn one pixel wide, independent of the transformation set on the painter.

Setting a pen width with a negative value is not supported.

另请参阅

setWidthF() width()

PySide2.QtGui.QPen. setWidthF ( width ) ¶

参数: width – qreal

Sets the pen width to the given width in pixels with floating point precision.

A line width of zero indicates a cosmetic pen. This means that the pen width is always drawn one pixel wide, independent of the transformation on the painter.

Setting a pen width with a negative value is not supported.

另请参阅

setWidth() widthF()

PySide2.QtGui.QPen. style ( ) ¶

返回类型: PenStyle

返回钢笔样式。

另请参阅

setStyle() Pen Style

PySide2.QtGui.QPen. swap ( other ) ¶

参数: other – QPen

Swaps pen other with this pen. This operation is very fast and never fails.

PySide2.QtGui.QPen. width ( ) ¶

返回类型: int

Returns the pen width with integer precision.

另请参阅

setWidth() widthF()

PySide2.QtGui.QPen. widthF ( ) ¶

返回类型: qreal

Returns the pen width with floating point precision.

另请参阅

setWidthF() width()


`SolidLine`	`DashLine`	`DotLine`

`DashDotLine`	`DashDotDotLine`	`CustomDashLine`

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QPen ¶

概要 ¶

函数 ¶

详细描述 ¶

Pen Style ¶

Cap Style ¶

Join Style ¶