我使用PyQt5和OpenCV编写了一个网络摄像头应用。它工作正常,但是我想进一步改进。我有几个问题:
1]在WebCam.py的第24行,当我单击退出按钮时,我想正确地打破while循环。我的意思是我需要定义一个“运行中”的布尔值,并将其从“ Ui_MainWindow”类传递给FrameGrabber类,以中断while循环,例如while cap.isOpened() & running:
循环中断后,我可以正常释放视频捕获。
2)Ui_MainWindow主要由Qt设计器生成。我必须在其中添加代码以利用面向对象的封装规则,例如不定义全局变量。但是,如果需要在UI中进行更改,是否需要一直编写代码?更新UI后,不更改代码的正确方法是什么?
3)如果您认为该代码对于代码的任何部分都更好,请随时发表评论,以便我也可以提高自己的技能。
谢谢您!
这里是WebCam.py:
from PyQt5 import QtCore, QtGui, QtWidgets
import cv2
class FrameGrabber(QtCore.QThread):
def __init__(self, parent=None):
super(FrameGrabber, self).__init__(parent)
signal = QtCore.pyqtSignal(QtGui.QImage)
def run(self):
cap = cv2.VideoCapture(0)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 720)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1280)
while cap.isOpened():
success, frame = cap.read()
if success:
image = QtGui.QImage(frame, frame.shape[1], frame.shape[0], QtGui.QImage.Format_BGR888)
self.signal.emit(image)
class Ui_MainWindow(QtWidgets.QMainWindow):
def __init__(self, MainWindow):
super().__init__()
self.MainWindow = MainWindow
self.setupUi(self.MainWindow)
self.grabber = FrameGrabber()
self.grabber.signal.connect(self.updateFrame)
self.grabber.start()
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.setWindowModality(QtCore.Qt.NonModal)
MainWindow.resize(1300, 799)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(MainWindow.sizePolicy().hasHeightForWidth())
MainWindow.setSizePolicy(sizePolicy)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.verticalLayout_2 = QtWidgets.QVBoxLayout(self.centralwidget)
self.verticalLayout_2.setObjectName("verticalLayout_2")
self.verticalLayout = QtWidgets.QVBoxLayout()
self.verticalLayout.setObjectName("verticalLayout")
self.label = QtWidgets.QLabel(self.centralwidget)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Maximum)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.label.sizePolicy().hasHeightForWidth())
self.label.setSizePolicy(sizePolicy)
font = QtGui.QFont()
font.setFamily("Arial")
font.setPointSize(12)
font.setBold(True)
font.setUnderline(True)
font.setWeight(75)
self.label.setFont(font)
self.label.setFrameShape(QtWidgets.QFrame.Box)
self.label.setTextFormat(QtCore.Qt.RichText)
self.label.setAlignment(QtCore.Qt.AlignCenter)
self.label.setObjectName("label")
self.verticalLayout.addWidget(self.label)
self.webCamDisplay = QtWidgets.QLabel(self.centralwidget)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Expanding)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.webCamDisplay.sizePolicy().hasHeightForWidth())
self.webCamDisplay.setSizePolicy(sizePolicy)
self.webCamDisplay.setFrameShape(QtWidgets.QFrame.Box)
self.webCamDisplay.setText("")
self.webCamDisplay.setObjectName("webCamDisplay")
self.verticalLayout.addWidget(self.webCamDisplay)
self.horizontalLayout = QtWidgets.QHBoxLayout()
self.horizontalLayout.setObjectName("horizontalLayout")
spacerItem = QtWidgets.QSpacerItem(500, 20, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Minimum)
self.horizontalLayout.addItem(spacerItem)
self.quitPushButton = QtWidgets.QPushButton(self.centralwidget)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Minimum)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.quitPushButton.sizePolicy().hasHeightForWidth())
self.quitPushButton.setSizePolicy(sizePolicy)
self.quitPushButton.setObjectName("quitPushButton")
self.horizontalLayout.addWidget(self.quitPushButton)
self.verticalLayout.addLayout(self.horizontalLayout)
self.verticalLayout_2.addLayout(self.verticalLayout)
MainWindow.setCentralWidget(self.centralwidget)
MainWindow.setFixedSize(MainWindow.width(), MainWindow.height())
self.quitPushButton.clicked.connect(self.quitApp)
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
@QtCore.pyqtSlot(QtGui.QImage)
def updateFrame(self, image):
self.webCamDisplay.setPixmap(QtGui.QPixmap.fromImage(image))
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "WebCam"))
self.label.setText(_translate("MainWindow", "WebCam Application"))
self.quitPushButton.setText(_translate("MainWindow", "Quit"))
def quitApp(self):
QtWidgets.QApplication.quit()
main.py:
from WebCam import Ui_MainWindow
from PyQt5.QtWidgets import QApplication, QMainWindow
if __name__ == "__main__":
import sys
app = QApplication(sys.argv)
MainWindow = QMainWindow()
ui = Ui_MainWindow(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
这是您应该知道的事情: