问题
Python 3, latest version of PyQt5 on Mac OS Mojave
I want a PyQt5 program in which the user could paint connected dots on an image (click distinctively and the points are automatically connected). It is important that I can only draw on the image in the QLabel widget (or an alternative widget) and not over the entire main window.
I can plot the image and get the the coordinates of the previous two clicks but when I want to paint on the image it happens underneath the image. Further I have troubles in getting the coordinates as input for my paintevent.
class Example(QWidget):
def __init__(self):
super().__init__()
title = "Darcy"
top = 400
left = 400
width = 550
height = 600
self.clickcount = 0
self.x = 0
self.y = 0
self.setWindowTitle(title)
self.setGeometry(top,left, width, height)
self.initUI()
def paintEvent(self, e):
qp = QPainter()
qp.begin(self)
self.drawLines(qp)
qp.end()
def drawLines(self, qp):
pen = QPen(Qt.black, 2, Qt.SolidLine)
qp.setPen(pen)
qp.drawLine(20, 40, 250, 40)
def initUI(self):
self.map = QLabel()
Im = QPixmap("GM_loc.png")
Im = Im.scaled(450,450)
self.map.setPixmap(Im)
self.loc = QLabel()
self.test = QLabel()
self.map.mousePressEvent = self.getPos
#organize in grid
grid = QGridLayout()
grid.setSpacing(10)
grid.addWidget(self.map, 0, 0)
grid.addWidget(self.loc,1,0)
grid.addWidget(self.test,2,0)
self.setLayout(grid)
self.show()
def getPos(self , event):
self.clickcount += 1
self.x_old = self.x
self.y_old = self.y
self.x = event.pos().x()
self.y = event.pos().y()
self.loc.setText("x = "+str(self.x)+" & y= "+str(self.y)+" & old x = " + str(self.x_old) + " & old y = " + str(self.y_old))
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
Thanks in advance! PS I am a rookie in PyQt5 so any hints in more efficient code are more than welcome!
回答1:
Try it:
import sys
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
class MyScribbling(QMainWindow):
def __init__(self):
super().__init__()
self.penOn = QAction(QIcon('Image/ok.png'), 'ON drawing', self)
self.penOn.triggered.connect(self.drawingOn)
self.penOff = QAction(QIcon('Image/exit.png'), 'OFF drawing', self)
self.penOff.triggered.connect(self.drawingOff)
toolbar = self.addToolBar('Tools')
toolbar.addAction(self.penOn)
toolbar.addAction(self.penOff)
self.scribbling = False
self.myPenColor = Qt.red
self.myPenWidth = 3
self.lastPoint = QPoint()
self.image = QPixmap("Image/picture.png")
self.setFixedSize(600, 600)
self.resize(self.image.width(), self.image.height())
self.setWindowTitle("drawing On / Off")
def paintEvent(self, event):
painter = QPainter(self)
painter.drawPixmap(self.rect(), self.image)
def mousePressEvent(self, event):
if (event.button() == Qt.LeftButton) and self.scribbling:
self.lastPoint = event.pos()
def mouseMoveEvent(self, event):
if (event.buttons() & Qt.LeftButton) and self.scribbling:
painter = QPainter(self.image)
painter.setPen(QPen(self.myPenColor, self.myPenWidth,
Qt.SolidLine, Qt.RoundCap, Qt.RoundJoin))
painter.drawLine(self.lastPoint, event.pos())
self.lastPoint = event.pos()
self.update()
def drawingOn(self):
self.scribbling = True
def drawingOff(self):
self.scribbling = False
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = MyScribbling()
ex.show()
sys.exit(app.exec_())
来源：https://stackoverflow.com/questions/52916101/pyqt5-how-to-interactively-paint-on-image-within-qlabel-widget