QPixmap ¶

函数 ¶

静态函数 ¶

读写图像文件 ¶

QPixmap provides several ways of reading an image file: The file can be loaded when constructing the QPixmap object, or by using the load() or loadFromData() functions later on. When loading an image, the file name can either refer to an actual file on disk or to one of the application’s embedded resources. See Qt 资源系统 overview for details on how to embed images and other resource files in the application’s executable.

只需调用 save() function to save a QPixmap 对象。

可获得支持的文件格式的完整列表，透过 supportedImageFormats() and supportedImageFormats() functions. New file formats can be added as plugins. By default, Qt supports the following formats:

格式	描述	Qt’s support
BMP	Windows 位图	读/写
GIF	Graphic Interchange Format (图形互换格式) 可选	Read
JPG	Joint Photographic Experts Group (联合摄影专家组)	读/写
JPEG	Joint Photographic Experts Group (联合摄影专家组)	读/写
PNG	Portable Network Graphics (便携式网络图形)	读/写
PBM	Portable Bitmap (便携式位图)	Read
PGM	Portable Graymap (便携式灰度图)	Read
PPM	Portable Pixmap (便携式像素图)	读/写
XBM	X11 Bitmap (X11 位图)	读/写
XPM	X11 Pixmap (X11 像素图)	读/写

像素图信息 ¶

QPixmap provides a collection of functions that can be used to obtain a variety of information about the pixmap:

	可用函数
几何体	size() , width() and height() functions provide information about the pixmap’s size. The rect() function returns the image’s enclosing rectangle.
Alpha 组件	hasAlphaChannel() 返回 true 若像素图是遵守 Alpha 通道的格式，否则返回 false 。 hasAlpha() , setMask() and mask() functions are legacy and should not be used. They are potentially very slow. createHeuristicMask() function creates and returns a 1-bpp heuristic mask (i.e. a QBitmap ) 对于此像素图而言。它通过在一个角选择颜色工作，然后从所有边缘开始切掉该颜色的像素。 createMaskFromColor() function creates and returns a mask (i.e. a QBitmap ) 对于基于给定颜色的像素图而言。
低级信息	depth() function returns the depth of the pixmap. The defaultDepth() function returns the default depth, i.e. the depth used by the application on the given screen. cacheKey() function returns a number that uniquely identifies the contents of the QPixmap 对象。

像素图转换 ¶

A QPixmap object can be converted into a QImage 使用 toImage() function. Likewise, a QImage can be converted into a QPixmap 使用 fromImage() . If this is too expensive an operation, you can use fromImage() 代替。

To convert a QPixmap to and from HICON you can use the QtWinExtras functions QtWin::toHICON() and QtWin::fromHICON() respectively.

像素图变换 ¶

QPixmap supports a number of functions for creating a new pixmap that is a transformed version of the original:

scaled() , scaledToWidth() and scaledToHeight() functions return scaled copies of the pixmap, while the copy() 函数创建 QPixmap that is a plain copy of the original one.

transformed() function returns a copy of the pixmap that is transformed with the given transformation matrix and transformation mode: Internally, the transformation matrix is adjusted to compensate for unwanted translation, i.e. transformed() returns the smallest pixmap containing all transformed points of the original pixmap. The static trueMatrix() function returns the actual matrix used for transforming the pixmap.

另请参阅

QBitmap QImage QImageReader QImageWriter

class QPixmap ¶

QPixmap(image)

QPixmap(arg__1)

QPixmap(arg__1)

QPixmap(fileName[, format=None[, flags=Qt.AutoColor]])

QPixmap(xpm)

QPixmap(w, h)

param w

int

param h

int

param xpm

char[]

param format

str

param image

QImage

param flags

ImageConversionFlags

param arg__1

QPixmap

param fileName

unicode

构造 null 像素图。

另请参阅

isNull()

从文件构造像素图采用给定 fileName . If the file does not exist or is of an unknown format, the pixmap becomes a null pixmap.

The loader attempts to read the pixmap using the specified format 。若 format is not specified (which is the default), the loader probes the file for a header to guess the file format.

The file name can either refer to an actual file on disk or to one of the application’s embedded resources. See the 资源系统 overview for details on how to embed images and other resource files in the application’s executable.

If the image needs to be modified to fit in a lower-resolution result (e.g. converting from 32-bit to 8-bit), use the flags to control the conversion.

fileName , format and flags parameters are passed on to load() . This means that the data in fileName is not compiled into the binary. If fileName contains a relative path (e.g. the filename only) the relevant file must be found relative to the runtime working directory.

另请参阅

Reading and Writing 图像 文件

构造像素图采用给定 width and height . If either width or height is zero, a null pixmap is constructed.

警告

This will create a QPixmap with uninitialized data. Call fill() to fill the pixmap with an appropriate color before drawing onto it with QPainter .

另请参阅

isNull()

PySide2.QtGui.QPixmap. cacheKey ( ) ¶

返回类型

qint64

Returns a number that identifies this QPixmap . Distinct QPixmap objects can only have the same cache key if they refer to the same contents.

The will change when the pixmap is altered.

PySide2.QtGui.QPixmap. convertFromImage ( img [ , flags=Qt.AutoColor ] ) ¶

参数

• img – QImage

• flags – ImageConversionFlags

返回类型

bool

Replaces this pixmap’s data with the given image 使用指定 flags 来控制转换。 flags 自变量是按位 OR 的 ImageConversionFlags 。传递 0 为 flags sets all the default options. Returns true if the result is that this pixmap is not null.

Note: this function was part of Qt 3 support in Qt 4.6 and earlier. It has been promoted to official API status in 4.7 to support updating the pixmap’s image without creating a new QPixmap as fromImage() would.

另请参阅

fromImage()

PySide2.QtGui.QPixmap. copy ( [ rect=QRect() ] ) ¶

参数

rect – QRect

返回类型

QPixmap

Returns a deep copy of the subset of the pixmap that is specified by the given rectangle . For more information on deep copies, see the 隐式数据共享 文档编制。

若给定 rectangle is empty, the whole image is copied.

另请参阅

operator=() QPixmap() Pixmap 变换

PySide2.QtGui.QPixmap. copy ( x , y , width , height ) ¶

参数

• x – int

• y – int

• width – int

• height – int

返回类型

QPixmap

这是重载函数。

Returns a deep copy of the subset of the pixmap that is specified by the rectangle QRect ( x , y , width , height ).

PySide2.QtGui.QPixmap. createHeuristicMask ( [ clipTight=true ] ) ¶

参数

clipTight – bool

返回类型

QBitmap

Creates and returns a heuristic mask for this pixmap.

The function works by selecting a color from one of the corners and then chipping away pixels of that color, starting at all the edges. If clipTight is true (the default) the mask is just large enough to cover the pixels; otherwise, the mask is larger than the data pixels.

The mask may not be perfect but it should be reasonable, so you can do things such as the following:

myPixmap = QPixmap()
myPixmap.setMask(myPixmap.createHeuristicMask())
												

This function is slow because it involves converting to/from a QImage , and non-trivial computations.

另请参阅

createHeuristicMask() createMaskFromColor()

PySide2.QtGui.QPixmap. createMaskFromColor ( maskColor [ , mode=Qt.MaskInColor ] ) ¶

参数

• maskColor – QColor

• mode – MaskMode

返回类型

QBitmap

Creates and returns a mask for this pixmap based on the given maskColor 。若 mode is MaskInColor , all pixels matching the maskColor will be transparent. If mode is MaskOutColor , all pixels matching the maskColor will be opaque.

This function is slow because it involves converting to/from a QImage .

另请参阅

createHeuristicMask() createMaskFromColor()

static PySide2.QtGui.QPixmap. defaultDepth ( ) ¶

返回类型

int

Returns the default pixmap depth used by the application.

On all platforms the depth of the primary screen will be returned.

注意

QGuiApplication must be created before calling this function.

另请参阅

depth() depth() Pixmap Information

PySide2.QtGui.QPixmap. fill ( device , ofs ) ¶

参数

• device – QPaintDevice

• ofs – QPoint

注意

此函数被弃用。

使用 QPainter or the fill( QColor ) overload instead.

PySide2.QtGui.QPixmap. fill ( device , xofs , yofs ) ¶

参数

• device – QPaintDevice

• xofs – int

• yofs – int

注意

此函数被弃用。

使用 QPainter or the fill( QColor ) overload instead.

PySide2.QtGui.QPixmap. fill ( [ fillColor=Qt.white ] ) ¶

参数

fillColor – QColor

填充像素图采用给定 color .

此函数的效果是未定义的，当像素图正在被绘制时。

另请参阅

Pixmap 变换

static PySide2.QtGui.QPixmap. fromImage ( image [ , flags=Qt.AutoColor ] ) ¶

参数

• image – QImage

• flags – ImageConversionFlags

返回类型

QPixmap

static PySide2.QtGui.QPixmap. fromImage ( image [ , flags=Qt.AutoColor ] ) ¶

参数

• image – QImage

• flags – ImageConversionFlags

返回类型

QPixmap

static PySide2.QtGui.QPixmap. fromImageInPlace ( image [ , flags=Qt.AutoColor ] ) ¶

参数

• image – QImage

• flags – ImageConversionFlags

返回类型

QPixmap

static PySide2.QtGui.QPixmap. fromImageReader ( imageReader [ , flags=Qt.AutoColor ] ) ¶

参数

• imageReader – QImageReader

• flags – ImageConversionFlags

返回类型

QPixmap

创建 QPixmap 从图像直接读取自 imageReader 。 flags 自变量是按位 OR 的 ImageConversionFlags 。传递 0 为 flags 设置所有默认选项。

在某些系统，将图像直接读取到 QPixmap 可以使用更少内存相比读取 QImage 以转换它到 QPixmap .

另请参阅

fromImage() toImage() Pixmap Conversion

static PySide2.QtGui.QPixmap. grabWidget ( widget [ , x=0 [ , y=0 [ , w=-1 [ , h=-1 ] ] ] ] ) ¶

参数

• widget – QObject

• x – int

• y – int

• w – int

• h – int

返回类型

QPixmap

注意

此函数被弃用。

使用 grab() 代替。

static PySide2.QtGui.QPixmap. grabWidget ( widget , rect ) ¶

参数

• widget – QObject

• rect – QRect

返回类型

QPixmap

注意

此函数被弃用。

使用 grab() 代替。

static PySide2.QtGui.QPixmap. grabWindow ( arg__1 [ , x=0 [ , y=0 [ , w=-1 [ , h=-1 ] ] ] ] ) ¶

参数

• arg__1 – WId

• x – int

• y – int

• w – int

• h – int

返回类型

QPixmap

注意

此函数被弃用。

创建并返回通过抓取内容构造的像素图，为给定 window 限定通过 QRect ( x , y , width , height ).

自变量 ( x , y ) 指定窗口偏移，而 ( width , height ) 指定要拷贝区域。若 width 为负，则函数把所有内容拷贝到窗口右边界。若 height 为负，则函数把所有内容拷贝到窗口底部。

窗口系统标识符 ( WId ) 可以被检索使用 winId() function. The rationale for using a window identifier and not a QWidget ，允许抓取不属于应用程序的窗口、窗口系统框架、等等。

The function grabs pixels from the screen, not from the window, i.e. if there is another window partially or entirely over the one you grab, you get pixels from the overlying window, too. The mouse cursor is generally not grabbed.

注意：在 X11 若给定 window doesn’t have the same depth as the root window, and another window partially or entirely obscures the one you grab, you will not 获取上方窗口的像素。像素图遮盖区域的内容将是未定义和未初始化的。

在 Windows Vista 及更高版本抓取分层窗口，其被创建通过设置 WA_TranslucentBackground 属性, 会不工作。相反，抓取桌面 Widget 应该工作。

警告

通常，抓住屏幕外区域是不安全的。这取决于底层窗口系统。

警告

The function is deprecated in Qt 5.0 since there might be platform plugins in which window system identifiers ( WId ) are local to a screen. Use grabWindow() 代替。

另请参阅

grabWidget() 屏幕截图范例 QScreen

PySide2.QtGui.QPixmap. hasAlpha ( ) ¶

返回类型

bool

返回 true 若此像素图有 Alpha 通道， or 有遮罩，否则返回 false .

另请参阅

hasAlphaChannel() mask()

PySide2.QtGui.QPixmap. hasAlphaChannel ( ) ¶

返回类型

bool

返回 true 若像素图是遵守 Alpha 通道的格式，否则返回 false .

另请参阅

hasAlpha()

PySide2.QtGui.QPixmap. isNull ( ) ¶

返回类型

bool

返回 true 若这是 null 像素图；否则返回 false .

A null pixmap has zero width, zero height and no contents. You cannot draw in a null pixmap.

PySide2.QtGui.QPixmap. isQBitmap ( ) ¶

返回类型

bool

返回 true 若这是 QBitmap ；否则返回 false .

PySide2.QtGui.QPixmap. load ( fileName [ , format=None [ , flags=Qt.AutoColor ] ] ) ¶

参数

• fileName – unicode

• format – str

• flags – ImageConversionFlags

返回类型

bool

从文件加载像素图采用给定 fileName . Returns true if the pixmap was successfully loaded; otherwise invalidates the pixmap and returns false .

The loader attempts to read the pixmap using the specified format 。若 format is not specified (which is the default), the loader probes the file for a header to guess the file format.

The file name can either refer to an actual file on disk or to one of the application’s embedded resources. See the 资源系统 overview for details on how to embed pixmaps and other resource files in the application’s executable.

If the data needs to be modified to fit in a lower-resolution result (e.g. converting from 32-bit to 8-bit), use the flags to control the conversion.

Note that QPixmaps are automatically added to the QPixmapCache when loaded from a file in main thread; the key used is internal and cannot be acquired.

另请参阅

loadFromData() Reading and Writing 图像 文件

PySide2.QtGui.QPixmap. loadFromData ( data [ , format=None [ , flags=Qt.AutoColor ] ] ) ¶

参数

• data – QByteArray

• format – str

• flags – ImageConversionFlags

返回类型

bool

这是重载函数。

Loads a pixmap from the binary data 使用指定 format and conversion flags .

PySide2.QtGui.QPixmap. loadFromData ( buf [ , format=None [ , flags=Qt.AutoColor ] ] ) ¶

参数

• buf – uchar

• format – str

• flags – ImageConversionFlags

返回类型

bool

Loads a pixmap from the len first bytes of the given binary data 。返回 true if the pixmap was loaded successfully; otherwise invalidates the pixmap and returns false .

The loader attempts to read the pixmap using the specified format 。若 format is not specified (which is the default), the loader probes the file for a header to guess the file format.

If the data needs to be modified to fit in a lower-resolution result (e.g. converting from 32-bit to 8-bit), use the flags to control the conversion.

另请参阅

load() Reading and Writing 图像 文件

This method must be used with an QPixmap object, not the class:

# Wrong
pixmap = QPixmap.loadFromData(...)
# Right
pixmap = QPixmap().loadFromData(...)
														

PySide2.QtGui.QPixmap. mask ( ) ¶

返回类型

QBitmap

Extracts a bitmap mask from the pixmap’s alpha channel.

警告

This is potentially an expensive operation. The mask of the pixmap is extracted dynamically from the pixeldata.

另请参阅

setMask() Pixmap Information

PySide2.QtGui.QPixmap. rect ( ) ¶

返回类型

QRect

Returns the pixmap’s enclosing rectangle.

另请参阅

Pixmap Information

PySide2.QtGui.QPixmap. save ( fileName [ , format=None [ , quality=-1 ] ] ) ¶

参数

• fileName – unicode

• format – str

• quality – int

返回类型

bool

PySide2.QtGui.QPixmap. save ( device [ , format=None [ , quality=-1 ] ] ) ¶

参数

• device – QIODevice

• format – str

• quality – int

返回类型

bool

这是重载函数。

此函数写入 QPixmap 到给定 device 使用指定图像文件 format and quality 因子。这可以被使用，例如：把像素图直接保存到 QByteArray :

pixmap = QPixmap()
bytes = QByteArray()
buffer(bytes)
buffer.open(QIODevice.WriteOnly)
pixmap.save(buffer, "PNG") # writes pixmap into bytes in PNG format
												

PySide2.QtGui.QPixmap. scaled ( s [ , aspectMode=Qt.IgnoreAspectRatio [ , mode=Qt.FastTransformation ] ] ) ¶

参数

• s – QSize

• aspectMode – AspectRatioMode

• mode – TransformationMode

返回类型

QPixmap

缩放像素图到给定 size ，使用宽高比和变换模式，指定通过 aspectRatioMode and transformMode .

• 若 aspectRatioMode is IgnoreAspectRatio ，像素图被比例缩放到 size .

• 若 aspectRatioMode is KeepAspectRatio ，像素图被比例缩放到尽可能大的矩形，不超出 size , 维持宽高比。

• 若 aspectRatioMode is KeepAspectRatioByExpanding ，像素图被比例缩放到尽可能小的矩形，超出 size , 维持宽高比。

若给定 size 为空，此函数返回 null 像素图。

在某些情况下，把像素图绘制到具有比例缩放设置的描绘器，比比例缩放像素图效果更好。如：当描绘器是基于 OpenGL 的实例，或当比例缩放因子快速变化时。

另请参阅

isNull() Pixmap 变换

PySide2.QtGui.QPixmap. scaled ( w , h [ , aspectMode=Qt.IgnoreAspectRatio [ , mode=Qt.FastTransformation ] ] ) ¶

参数

• w – int

• h – int

• aspectMode – AspectRatioMode

• mode – TransformationMode

返回类型

QPixmap

这是重载函数。

Returns a copy of the pixmap scaled to a rectangle with the given width and height according to the given aspectRatioMode and transformMode .

若 width 或 height is zero or negative, this function returns a null pixmap.

PySide2.QtGui.QPixmap. scaledToHeight ( h [ , mode=Qt.FastTransformation ] ) ¶

参数

• h – int

• mode – TransformationMode

返回类型

QPixmap

Returns a scaled copy of the image. The returned image is scaled to the given height using the specified transformation mode . The width of the pixmap is automatically calculated so that the aspect ratio of the pixmap is preserved.

若 height 为 0 或负数，返回 null 像素图。

另请参阅

isNull() Pixmap 变换

PySide2.QtGui.QPixmap. scaledToWidth ( w [ , mode=Qt.FastTransformation ] ) ¶

参数

• w – int

• mode – TransformationMode

返回类型

QPixmap

Returns a scaled copy of the image. The returned image is scaled to the given width using the specified transformation mode . The height of the pixmap is automatically calculated so that the aspect ratio of the pixmap is preserved.

若 width 为 0 或负数，返回 null 像素图。

另请参阅

isNull() Pixmap 变换

PySide2.QtGui.QPixmap. scroll ( dx , dy , rect [ , exposed=None ] ) ¶

参数

• dx – int

• dy – int

• rect – QRect

• exposed – QRegion

Scrolls the area rect of this pixmap by ( dx , dy ). The exposed region is left unchanged. You can optionally pass a pointer to an empty QRegion to get the region that is exposed by the scroll operation.

pixmap = QPixmap("background.png")
exposed = QRegion()
pixmap.scroll(10, 10, pixmap.rect(), exposed)
												

You cannot scroll while there is an active painter on the pixmap.

另请参阅

scroll() scroll()

PySide2.QtGui.QPixmap. scroll ( dx , dy , x , y , width , height [ , exposed=None ] ) ¶

参数

• dx – int

• dy – int

• x – int

• y – int

• width – int

• height – int

• exposed – QRegion

This convenience function is equivalent to calling ( dx , dy , QRect ( x , y , width , height ), exposed ).

另请参阅

scroll() scroll()

PySide2.QtGui.QPixmap. setDevicePixelRatio ( scaleFactor ) ¶

参数

scaleFactor – qreal

Sets the device pixel ratio for the pixmap. This is the ratio between image pixels and device-independent pixels.

默认 scaleFactor is 1.0. Setting it to something else has two effects:

QPainters that are opened on the pixmap will be scaled. For example, painting on a 200x200 image if with a ratio of 2.0 will result in effective (device-independent) painting bounds of 100x100.

Code paths in Qt that calculate layout geometry based on the pixmap size will take the ratio into account: QSize layoutSize = pixmap. size() / pixmap. devicePixelRatio() The net effect of this is that the pixmap is displayed as high-DPI pixmap rather than a large pixmap (see 绘制 High Resolution 版本 of Pixmaps and 图像 ).

另请参阅

devicePixelRatio()

PySide2.QtGui.QPixmap. setMask ( arg__1 ) ¶

参数

arg__1 – QBitmap

设置遮罩位图。

此函数合并 mask with the pixmap’s alpha channel. A pixel value of 1 on the mask means the pixmap’s pixel is unchanged; a value of 0 means the pixel is transparent. The mask must have the same size as this pixmap.

Setting a null mask resets the mask, leaving the previously transparent pixels black. The effect of this function is undefined when the pixmap is being painted on.

警告

这是潜在的昂贵操作。

另请参阅

mask() Pixmap 变换 QBitmap

PySide2.QtGui.QPixmap. size ( ) ¶

返回类型

QSize

返回像素图尺寸。

另请参阅

width() height() Pixmap Information

PySide2.QtGui.QPixmap. swap ( other ) ¶

参数

other – QPixmap

交换像素图 other 与此像素图。此操作非常快且从不失败。

PySide2.QtGui.QPixmap. toImage ( ) ¶

返回类型

QImage

将像素图转换成 QImage 。返回 null 图像，若转换失败。

If the pixmap has 1-bit depth, the returned image will also be 1 bit deep. Images with more bits will be returned in a format closely represents the underlying system. Usually this will be Format_ARGB32_Premultiplied for pixmaps with an alpha and Format_RGB32 or Format_RGB16 for pixmaps without alpha.

Note that for the moment, alpha masks on monochrome images are ignored.

另请参阅

fromImage() 图像 格式

PySide2.QtGui.QPixmap. transformed ( arg__1 [ , mode=Qt.FastTransformation ] ) ¶

参数

• arg__1 – QMatrix

• mode – TransformationMode

返回类型

QPixmap

注意

此函数被弃用。

PySide2.QtGui.QPixmap. transformed ( arg__1 [ , mode=Qt.FastTransformation ] ) ¶

参数

• arg__1 – QTransform

• mode – TransformationMode

返回类型

QPixmap

static PySide2.QtGui.QPixmap. trueMatrix ( m , w , h ) ¶

参数

• m – QMatrix

• w – int

• h – int

返回类型

QMatrix

注意

此函数被弃用。

static PySide2.QtGui.QPixmap. trueMatrix ( m , w , h ) ¶

参数

• m – QTransform

• w – int

• h – int

返回类型

QTransform