QSvgRenderer 类用于将 SVG 文件内容绘制到描绘设备上。 更多...
头: | #include <QSvgRenderer> |
qmake: | QT += svg |
Since: | Qt 4.1 |
继承: | QObject |
该类在 Qt 4.1 引入。
注意: 此类的所有函数 可重入 .
QSvgRenderer (QXmlStreamReader * contents , QObject * parent = nullptr) | |
QSvgRenderer (const QByteArray & contents , QObject * parent = nullptr) | |
QSvgRenderer (const QString & filename , QObject * parent = nullptr) | |
QSvgRenderer (QObject * parent = nullptr) | |
virtual | ~QSvgRenderer () |
bool | animated () const |
Qt::AspectRatioMode | aspectRatioMode () const |
QRectF | boundsOnElement (const QString & id ) const |
QSize | defaultSize () const |
bool | elementExists (const QString & id ) const |
int | framesPerSecond () const |
bool | isValid () const |
void | setAspectRatioMode (Qt::AspectRatioMode mode ) |
void | setFramesPerSecond (int num ) |
void | setViewBox (const QRect & viewbox ) |
void | setViewBox (const QRectF & viewbox ) |
QTransform | transformForElement (const QString & id ) const |
QRect | viewBox () const |
QRectF | viewBoxF () const |
bool | load (QXmlStreamReader * contents ) |
bool | load (const QByteArray & contents ) |
bool | load (const QString & filename ) |
void | render (QPainter * painter , const QString & elementId , const QRectF & bounds = QRectF()) |
void | render (QPainter * painter , const QRectF & bounds ) |
void | render (QPainter * painter ) |
void | repaintNeeded () |
Using QSvgRenderer, Scalable Vector Graphics (SVG) can be rendered onto any QPaintDevice subclass, including QWidget , QImage , and QGLWidget.
QSvgRenderer provides an API that supports basic features of SVG rendering, such as loading and rendering of static drawings, and more interactive features like animation. Since the rendering is performed using QPainter , SVG drawings can be rendered on any subclass of QPaintDevice .
SVG drawings are either loaded when an QSvgRenderer is constructed, or loaded later using the load () functions. Data is either supplied directly as serialized XML, or indirectly using a file name. If a valid file has been loaded, either when the renderer is constructed or at some later time, isValid () returns true; otherwise it returns false. QSvgRenderer provides the render () slot to render the current document, or the current frame of an animated document, using a given painter.
The defaultSize () function provides information about the amount of space that is required to render the currently loaded SVG file. This is useful for paint devices, such as QWidget , that often need to supply a size hint to their parent layout. The default size of a drawing may differ from its visible area, found using the viewBox 特性。
Animated SVG drawings are supported, and can be controlled with a simple collection of functions and properties:
Finally, the QSvgRenderer class provides the repaintNeeded () signal which is emitted whenever the rendering of the document needs to be updated.
另请参阅 QSvgWidget , Qt SVG C++ 类 , SVG 查看器范例 ,和 QPicture .
how rendering adheres to the SVG view box aspect ratio
接受模式:
该特性在 Qt 5.15 引入。
访问函数:
Qt::AspectRatioMode | aspectRatioMode () const |
void | setAspectRatioMode (Qt::AspectRatioMode mode ) |
This property holds the number of frames per second to be shown
The number of frames per second is 0 if the current document is not animated.
访问函数:
int | framesPerSecond () const |
void | setFramesPerSecond (int num ) |
另请参阅 animated ().
This property holds the rectangle specifying the visible area of the document in logical coordinates
该特性在 Qt 4.2 引入。
访问函数:
QRectF | viewBoxF () const |
void | setViewBox (const QRect & viewbox ) |
void | setViewBox (const QRectF & viewbox ) |
Constructs a new renderer with the given parent and loads the SVG data using the stream reader specified by contents .
该函数在 Qt 4.5 引入。
Constructs a new renderer with the given parent and loads the SVG data from the byte array specified by contents .
Constructs a new renderer with the given parent and loads the contents of the SVG file with the specified filename .
Constructs a new renderer with the given parent .
[slot]
bool
QSvgRenderer::
load
(
QXmlStreamReader
*
contents
)
Loads the specified SVG in contents ,返回 true 若内容被成功剖析;否则返回 false。
The reader will be used from where it currently is positioned. If
contents
is
null
, behavior is undefined.
该函数在 Qt 4.5 引入。
[slot]
bool
QSvgRenderer::
load
(const
QByteArray
&
contents
)
加载指定 SVG 格式 contents ,返回 true 若内容被成功剖析;否则返回 false。
[slot]
bool
QSvgRenderer::
load
(const
QString
&
filename
)
Loads the SVG file specified by filename ,返回 true 若内容被成功剖析;否则返回 false。
[slot]
void
QSvgRenderer::
render
(
QPainter
*
painter
, const
QString
&
elementId
, const
QRectF
&
bounds
= QRectF())
Renders the given element with elementId 使用给定 painter on the specified bounds . If the bounding rectangle is not specified the SVG element is mapped to the whole paint device.
[slot]
void
QSvgRenderer::
render
(
QPainter
*
painter
, const
QRectF
&
bounds
)
Renders the current document, or the current frame of an animated document, using the given painter on the specified bounds within the painter. If bounds is not empty, the output will be scaled to fill it, ignoring any aspect ratio implied by the SVG.
[slot]
void
QSvgRenderer::
render
(
QPainter
*
painter
)
Renders the current document, or the current frame of an animated document, using the given painter .
[signal]
void
QSvgRenderer::
repaintNeeded
()
This signal is emitted whenever the rendering of the document needs to be updated, usually for the purposes of animation.
[虚拟]
QSvgRenderer::
~QSvgRenderer
()
Destroys the renderer.
Returns true if the current document contains animated elements; otherwise returns false.
另请参阅 framesPerSecond ().
Returns bounding rectangle of the item with the given id . The transformation matrix of parent elements is not affecting the bounds of the element.
该函数在 Qt 4.2 引入。
另请参阅 transformForElement ().
Returns the default size of the document contents.
Returns true if the element with the given id exists in the currently parsed SVG file and is a renderable element.
Note: this method returns true only for elements that can be rendered. Which implies that elements that are considered part of the fill/stroke style properties, e.g. radialGradients even tough marked with "id" attributes will not be found by this method.
该函数在 Qt 4.2 引入。
Returns true if there is a valid current document; otherwise returns false.
Returns the transformation matrix for the element with the given id . The matrix is a product of the transformation of the element's parents. The transformation of the element itself is not included.
To find the bounding rectangle of the element in logical coordinates, you can apply the matrix on the rectangle returned from boundsOnElement ().
该函数在 Qt 5.15 引入。
另请参阅 boundsOnElement ().
返回 viewBoxF ().toRect().
另请参阅 setViewBox () 和 viewBoxF ().