python - PySide2 QPushButton.setText()在暂停视频源后使我的应用程序崩溃

Question

我正在创建一个小部件，该小部件在从QLabel派生的自定义小部件上显示来自机器视觉相机的实时相机供稿。
但是，当我停止提要的实时 View 时，我的程序将崩溃而无提示。
使用调试器时，最后执行的行是停止供稿的按钮上的self.ui.btn_prev_st.setText('Start')。如果我跳过它，则进入CameraControl的update_image()，但是在调试器仍然暂停的同时，应用程序将关闭。
在那之后，app.exec_()似乎返回并且应用程序关闭。
对于图像获取，我使用pymba。我在self.cam.disarm()之前调用setText()函数，但是如果我逐步执行，它会正常执行。 (它在结尾处调用gc.collect()，但这不应该做什么？)
因此，要么我在Qt中打断了某个东西，要么是pymba撤防功能是造成这种情况的原因。
有人有主意吗？我提供了一个最小的工作示例。
提前致谢!
main.py代码:

import sys
import os
import atexit

from PySide2.QtWidgets import QApplication, QMainWindow
from PySide2.QtCore import QFile, Signal
from PySide2.QtUiTools import QUiLoader
from ui_main import Ui_main
from camera_control import CameraControl

class main(QMainWindow):
    start_acquisition_signal = Signal()
    stop_acquisition_signal = Signal()
    def __init__(self):
        super(main, self).__init__()
        self.ui = Ui_main()
        self.ui.setupUi(self)
        atexit.register(self.cleanup)
        self.ui.btn_prev_st.clicked.connect(self.prev_start_pushed)
        self.ui.btn_set_roi.clicked.connect(self.ui.camera_prev.apply_roi)
        self.ui.btn_reset_roi.clicked.connect(self.ui.camera_prev.reset_roi)
        self.start_acquisition_signal.connect(self.ui.camera_prev.start_preview)
        self.stop_acquisition_signal.connect(self.ui.camera_prev.stop_preview)

    def __del__(self):
        del self.ui.camera_prev

    def cleanup(self):
        del self

    def load_ui(self):
        loader = QUiLoader()
        path = os.path.join(os.path.dirname(__file__), "form.ui")
        ui_file = QFile(path)
        ui_file.open(QFile.ReadOnly)
        loader.load(ui_file, self)
        ui_file.close()

    def prev_start_pushed(self, event):
        if self.ui.btn_prev_st.text() != 'Stop':
            self.start_acquisition_signal.emit()
            self.ui.btn_prev_st.setText('Stop')
        else:
            self.stop_acquisition_signal.emit()
            self.ui.btn_prev_st.setText('Start')

if __name__ == "__main__":
    app = QApplication([])
    widget = main()
    widget.show()
    sys.exit(app.exec_())

camera_control.py:

from typing import Optional
import cv2
import numpy as np
from pymba import Vimba, Frame

from PySide2 import QtGui
from PySide2.QtWidgets import QLabel
from PySide2.QtCore import Signal, Slot, Qt, QPoint, QRect, QSize
from PySide2.QtGui import QPixmap

class CameraControl(QLabel):
    change_pixmap_signal = Signal(np.ndarray)
    def __init__(self, parent=None):
        super(CameraControl, self).__init__(parent)
        self._first_show = True # whether form is shown for the first time
        self.is_running = False
        self.change_pixmap_signal.connect(self.update_image)
        self.vimba = Vimba()
        self.vimba.startup()
        self.cam = self.vimba.camera(0)
        try:
            self.cam.close()
        except:
            pass
        self.cam.open()
        self.setup_camera()
        self.update()

    def __del__(self):
        try:
            self.cam.disarm()
            self.cam.close()
        except:
            pass
        del self.vimba

    @Slot()
    def stop_preview(self):
        self.is_running = False
        #self.cam.stop_frame_acquisition()
        self.cam.disarm()

    @Slot()
    def start_preview(self):
        self.cam.arm('Continuous', self.frame_handler)
        self.cam.start_frame_acquisition()
        self.is_running = True

    def frame_handler(self, frame: Frame, delay: Optional[int] = 1) -> None:
        img = frame.buffer_data_numpy()
        self.change_pixmap_signal.emit(img)

    @Slot(np.ndarray)
    def update_image(self, cv_img):
        """ Updates the image_label with a new opencv image"""
        qt_img = self.convert_cv_qt(cv_img)
        self.setPixmap(qt_img)

ui_main.py:

from PySide2.QtCore import *
from PySide2.QtGui import *
from PySide2.QtWidgets import *

from camera_control import CameraControl


class Ui_main(object):
    def setupUi(self, main):
        if not main.objectName():
            main.setObjectName(u"main")
        main.resize(1192, 752)
        self.centralwidget = QWidget(main)
        self.centralwidget.setObjectName(u"centralwidget")
        self.box_preview = QGroupBox(self.centralwidget)
        self.box_preview.setObjectName(u"box_preview")
        self.box_preview.setGeometry(QRect(10, 10, 601, 391))
        self.btn_prev_st = QPushButton(self.box_preview)
        self.btn_prev_st.setObjectName(u"btn_prev_st")
        self.btn_prev_st.setGeometry(QRect(20, 20, 75, 23))
        self.camera_prev = CameraControl(self.box_preview)
        self.camera_prev.setObjectName(u"camera_prev")
        self.camera_prev.setGeometry(QRect(110, 20, 480, 360))
        self.camera_prev.setMinimumSize(QSize(0, 0))
        self.camera_prev.setBaseSize(QSize(640, 480))
        self.camera_prev.setMouseTracking(True)
        self.camera_prev.setFrameShape(QFrame.Panel)
        self.camera_prev.setScaledContents(False)
        self.camera_prev.setAlignment(Qt.AlignCenter)
        main.setCentralWidget(self.centralwidget)
        self.menubar = QMenuBar(main)
        self.menubar.setObjectName(u"menubar")
        self.menubar.setGeometry(QRect(0, 0, 1192, 21))
        main.setMenuBar(self.menubar)
        self.statusbar = QStatusBar(main)
        self.statusbar.setObjectName(u"statusbar")
        main.setStatusBar(self.statusbar)

        self.retranslateUi(main)

        QMetaObject.connectSlotsByName(main)
    # setupUi

    def retranslateUi(self, main):
        main.setWindowTitle(QCoreApplication.translate("main", u"main", None))
        self.box_preview.setTitle(QCoreApplication.translate("main", u"Preview", None))
        self.btn_prev_st.setText(QCoreApplication.translate("main", u"Start", None))
    # retranslateUi

Answer 1

我决定改用官方的VimbyPython库。这解决了问题。