如何使用PyQt更新QGraphicsView中的QPixmap
作者:互联网
我试图在QGraphicsView内的QPixmap上绘画.这幅画很好用,但QGraphicsView不会更新它.
这是一些工作代码:
#!/usr/bin/env python
from PyQt4 import QtCore
from PyQt4 import QtGui
class Canvas(QtGui.QPixmap):
""" Canvas for drawing"""
def __init__(self, parent=None):
QtGui.QPixmap.__init__(self, 64, 64)
self.parent = parent
self.imH = 64
self.imW = 64
self.fill(QtGui.QColor(0, 255, 255))
self.color = QtGui.QColor(0, 0, 0)
def paintEvent(self, point=False):
if point:
p = QtGui.QPainter(self)
p.setPen(QtGui.QPen(self.color, 1, QtCore.Qt.SolidLine))
p.drawPoints(point)
def clic(self, mouseX, mouseY):
self.paintEvent(QtCore.QPoint(mouseX, mouseY))
class GraphWidget(QtGui.QGraphicsView):
""" Display, zoom, pan..."""
def __init__(self):
QtGui.QGraphicsView.__init__(self)
self.im = Canvas(self)
self.imH = self.im.height()
self.imW = self.im.width()
self.zoomN = 1
self.scene = QtGui.QGraphicsScene(self)
self.scene.setItemIndexMethod(QtGui.QGraphicsScene.NoIndex)
self.scene.setSceneRect(0, 0, self.imW, self.imH)
self.scene.addPixmap(self.im)
self.setScene(self.scene)
self.setTransformationAnchor(QtGui.QGraphicsView.AnchorUnderMouse)
self.setResizeAnchor(QtGui.QGraphicsView.AnchorViewCenter)
self.setMinimumSize(400, 400)
self.setWindowTitle("pix")
def mousePressEvent(self, event):
if event.buttons() == QtCore.Qt.LeftButton:
pos = self.mapToScene(event.pos())
self.im.clic(pos.x(), pos.y())
#~ self.scene.update(0,0,64,64)
#~ self.updateScene([QtCore.QRectF(0,0,64,64)])
self.scene.addPixmap(self.im)
print('items')
print(self.scene.items())
else:
return QtGui.QGraphicsView.mousePressEvent(self, event)
def wheelEvent(self, event):
if event.delta() > 0:
self.scaleView(2)
elif event.delta() < 0:
self.scaleView(0.5)
def scaleView(self, factor):
n = self.zoomN * factor
if n < 1 or n > 16:
return
self.zoomN = n
self.scale(factor, factor)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
widget = GraphWidget()
widget.show()
sys.exit(app.exec_())
mousePressEvent在QPixmap上做了一些绘画.但我发现更新显示器的唯一解决方案是创建一个新实例(这不是一个好的解决方案).
我该如何更新它?
解决方法:
pixmap无法链接到您的场景,该项目使用它的内部副本,因此您必须使用新的pixmap更新QGraphicsPixmapItem:
def __init__(self):
...
# save the item as a member
self.imItem = self.scene.addPixmap(self.im)
...
def mousePressEvent(self, event):
if event.buttons() == QtCore.Qt.LeftButton:
pos = self.mapToScene(event.pos())
self.im.clic(pos.x(), pos.y())
self.imItem.setPïxmap(self.im)
...
但是让你的类Canvas从QGraphicsPixmapItem继承而不是QPixmap更有意义,你仍然需要使用pixmap()获取pixmap,在其上绘制,并调用setPixmap来更新它.作为奖励,该代码将在项目自己的mousePressEvent方法中.
标签:python,pyqt,repaint,qgraphicsview,qpixmap 来源: https://codeday.me/bug/20190704/1372693.html