PyQt5，选择图像时出现“无法读取内存”错误

我从 tkinter 切换到 PyQt5. 作为练习，我想创建一个简单的图像编辑器也使用PIL. 到目前为止，该程序只有Label一个按钮可以调用文件选择对话框，并且在选择一个文件时，在7个图像中，仅显示一个图像Label，在其他情况下，以下是错误： http： //mmolabel.ru/ wp-content/uploads/2018 /03/pamyat-ne-mozhet-byt-read.jpg

这是小部件代码

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(800, 600)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.label = QtWidgets.QLabel(self.centralwidget)
        self.label.setGeometry(QtCore.QRect(70, 40, 651, 391))
        self.label.setObjectName("label")
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(644, 560, 131, 23))
        self.pushButton.setObjectName("pushButton")
        MainWindow.setCentralWidget(self.centralwidget)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.label.setText(_translate("MainWindow", "Здесь будет фото"))
        self.pushButton.setText(_translate("MainWindow", "Выберите изображение"))

这是逻辑文件，你需要运行它，并且从与第一个相同的目录中运行

from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QFileDialog
from pr_visual import Ui_MainWindow
import sys
from PIL import Image
from PIL.ImageQt import ImageQt
def opendialog():
    dialog = QFileDialog()
    fname = dialog.getOpenFileName(None, 'Open file', '/')[0]
    img = Image.open(fname)
    width = img.size[0]
    height = img.size[1]
    qimg = ImageQt(img)
    width = img.size[0]
    height = img.size[1]
    pixmap = QtGui.QPixmap.fromImage(qimg)
    ui.label.setGeometry(QtCore.QRect(0, 0, width, height))
    ui.label.setPixmap(pixmap)

#Create main window
app = QtWidgets.QApplication(sys.argv)
window = QtWidgets.QMainWindow()
ui = Ui_MainWindow()
ui.setupUi(window)
window.setWindowTitle('PR')
window.show()

#Logic
ui.pushButton.clicked.connect( opendialog )

#mainloop
sys.exit(app.exec_())