我试图为多层图片重新实施the scribble demo app。我正在努力在场景中绘制像素图,因为画家抱怨早期被摧毁。
QPaintDevice:无法销毁正在绘制的绘图设备
你可以帮我修改我的代码,这样你就可以用红笔在roilayer像素图上绘图,并且这个图层开始透明。
#!/usr/bin/python3
import sys
import os
from PyQt5.QtWidgets import QApplication, QGraphicsView, QGraphicsScene, QGraphicsPixmapItem
from PyQt5.QtGui import QPixmap, QImage, QPainter, QPen
from PyQt5.QtCore import Qt, QRect
class Main(QGraphicsView):
def __init__(self):
super().__init__()
self.setWindowTitle("Scribble with layers")
self.scene = QGraphicsScene()
self.setScene(self.scene)
self.image = QImage('sample/test.bmp')
self.imlayer = QGraphicsPixmapItem(QPixmap.fromImage(self.image))
self.roilayer = QGraphicsPixmapItem(QPixmap(self.image.size()))
self.addlayer(self.imlayer)
self.addlayer(self.roilayer)
self.drawing = False
self.lastPoint = None
self.pencolour = Qt.red
self.penwidth = 2
self.show()
def addlayer(self, layer):
self.scene.addItem(layer)
self.updateviewer()
def updateviewer(self):
self.fitInView(self.sceneRect(), Qt.KeepAspectRatio)
def mousePressEvent(self, event):
# print(event.modifiers())
if event.button() == Qt.LeftButton:
self.lastPoint = event.pos()
self.drawing = True
def mouseMoveEvent(self, event):
if (event.buttons() & Qt.LeftButton) and self.drawing:
self.drawlineto(event.pos())
def mouseReleaseEvent(self, event):
if event.button() == Qt.LeftButton and self.drawing:
self.drawlineto(event.pos())
self.drawing = False
def drawlineto(self, position):
pixmap = self.roilayer.pixmap()
painter = QPainter(pixmap)
painter.setPen(QPen(self.pencolour, self.penwidth, Qt.SolidLine,
Qt.RoundCap, Qt.RoundJoin))
painter.drawLine(self.lastPoint, position)
self.imlayer.setPixmap(pixmap)
self.modified = True
rad = self.penwidth / 2 + 2
self.update(QRect(self.lastPoint, position).normalized().adjusted(-rad, -rad, +rad, +rad))
self.lastPoint = position
if __name__ == '__main__':
app = QApplication([])
main = Main()
sys.exit(app.exec_())
答案 0 :(得分:0)
我遇到了同样的问题。解决方案是对这部分代码执行以下操作:
def drawlineto(self, position):
pixmap = self.roilayer.pixmap()
painter = QPainter()
painter.begin(pixmap)
painter.setPen(QPen(self.pencolour, self.penwidth, Qt.SolidLine,
Qt.RoundCap, Qt.RoundJoin))
painter.drawLine(self.lastPoint, position)
painter.end()
self.imlayer.setPixmap(pixmap)
self.modified = True