【发布时间】：2021-02-28 14:49:16
【问题描述】：
我需要在这个小部件中实现撤消功能，使用组合键 Ctrl + Z 激活。我可以在传入构造函数的输入中的图像上画线。因此，我们的想法是从行列表中删除最后一项（每次绘制一条线时，我都会在此列表中添加一条线），并在按下 Ctrl + Z 时重新绘制所有其他线。如何实现此刷新？有没有更有效的方法来做这样的事情？
代码：
from PyQt5 import QtWidgets, Qt
from PyQt5.QtCore import QSize, QPoint
from PyQt5.QtGui import QImage
import numpy as np
import sys
from PyQt5.QtCore import Qt, QPoint
from PyQt5.QtWidgets import QApplication
from PyQt5.QtGui import QPixmap, QPainter, QPen
class DistanceWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(DistanceWindow, self).__init__(parent)
self.axial = np.random.rand(512, 512)
print(self.axial.shape)
self.axial = QPixmap(QImage(self.axial, self.axial.shape[1], self.axial.shape[0], QImage.Format_Indexed8))
self.axialWidget = DrawWidget(self.axial)
class DrawWidget(QtWidgets.QWidget):
def __init__(self, image):
super().__init__()
self.drawing = False
self.startPoint = None
self.endPoint = None
self.image = image
self.setGeometry(100, 100, 500, 300)
self.resize(self.image.width(), self.image.height())
self.show()
self.lines = []
def mousePressEvent(self, event):
if event.button() == Qt.LeftButton:
self.startPoint = event.pos()
def mouseMoveEvent(self, event):
if self.startPoint:
self.endPoint = event.pos()
self.update()
def mouseReleaseEvent(self, event):
if self.startPoint and self.endPoint:
self.updateImage()
def paintEvent(self, event):
painter = QPainter(self)
dirtyRect = event.rect()
painter.drawImage(dirtyRect, QImage(self.image), dirtyRect)
if self.startPoint and self.endPoint:
painter.drawLine(self.startPoint, self.endPoint)
def updateImage(self):
if self.startPoint and self.endPoint:
painter = QPainter(self.image)
painter.setPen(QPen(Qt.red, 2, Qt.SolidLine, Qt.RoundCap, Qt.RoundJoin))
painter.drawLine(self.startPoint, self.endPoint)
firstPoint = np.array([self.startPoint.x(), self.startPoint.y()])
secondPoint = np.array([self.endPoint.x(), self.endPoint.y()])
distance = np.sqrt((secondPoint[0]-firstPoint[0])**2 + (secondPoint[1]-firstPoint[1])**2)
painter.setPen(QPen(Qt.yellow))
painter.drawText(secondPoint[0], secondPoint[1] + 10, str(distance) + 'mm')
#line info
line = {}
line['points'] = [self.startPoint, self.endPoint]
line['distance'] = distance
self.lines.append(line)
#####################################
painter.end()
self.startPoint = self.endPoint = None
self.update()
def keyPressEvent(self, event):
if event.key() == (Qt.Key_Control and Qt.Key_Z):
self.undo()
def undo(self):
#Delete the last line from self.lines and draw all the others
if __name__ == '__main__':
app = QApplication(sys.argv)
main = DistanceWindow()
sys.exit(app.exec_())
【问题讨论】：
-
这需要一个最小的可重现示例。请制作出来，以便人们可以直接运行代码并对其进行测试。
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@JussiNurminen 谢谢，我添加了重现示例的代码
标签： python user-interface pyqt pyqt5