问题描述
我正在使用python3和pyside2开发Ubuntu 20.04，Qt是版本5。
我编写了这个简单的Python脚本，以测试为以后要处理的更大项目保存网络摄像头视频的能力。
基本上，我首先希望使用此演示脚本，并在名为“ frame”的小部件中仅显示来自摄像机的流，但是似乎丢失了一些东西，因为在终端上打印了一条消息：
在没有取景器的情况下启动相机
我在QtCreator中制作了GUI，然后用pyside-uic对其进行了转换。
我将黑色背景色应用于名为“框架”的小部件。 当我单击“连接”按钮时，我希望看到视频开始并显示，但是“框架”保持黑色，并且在终端中收到有关取景器的消息。 取景器不是显示视频的地方（又称小部件）吗？
我觉得有问题，但是我认为可以轻松解决，因为当我单击该按钮进行连接时，网络摄像头的LED（正确）点亮了。
这是python代码：
from pyside2.QtMultimedia import QCamera,QCameraInfo,QCamera
from pyside2.QtMultimedia import *
from pyside2.QtMultimedia import QCameraviewfinderSettings
from pyside2.QtCore import *
from pyside2.QtGui import *
from pyside2.QtWidgets import *
import MainWindow
import sys
from MainWindow import Ui_MainWindow
class MainWindow(QMainWindow,Ui_MainWindow):
def __init__(self,*args,**kwargs):
super(MainWindow,self).__init__(*args,**kwargs)
self.setupUi(self)
self.available_cameras = QCameraInfo.availableCameras()
print(self.available_cameras[0].description())
self.camera_comboBox.addItem( self.available_cameras[0].description() )
self.camera_comboBox.addItem( self.available_cameras[1].description() )
self.connect_btn.clicked.connect(self.connect_btn_clicked)
def connect_btn_clicked(self):
self.camera = QCamera(self.available_cameras[0])
self.frame.setSizePolicy(QSizePolicy.Maximum,QSizePolicy.Maximum)
self.camera.setViewfinder(self.frame)
self.camera.start()
app = QApplication(sys.argv)
window = MainWindow()
window.show()
app.exec_()
这是MainWindow.py代码
# -*- coding: utf-8 -*-
################################################################################
## Form generated from reading UI file 'mainwindow.ui'
##
## Created by: Qt User Interface Compiler version 5.15.1
##
## WARNING! All changes made in this file will be lost when recompiling UI file!
################################################################################
from pyside2.QtCore import *
from pyside2.QtGui import *
from pyside2.QtWidgets import *
class Ui_MainWindow(object):
def setupUi(self,MainWindow):
if not MainWindow.objectName():
MainWindow.setobjectName(u"MainWindow")
MainWindow.resize(800,600)
self.centralwidget = QWidget(MainWindow)
self.centralwidget.setobjectName(u"centralwidget")
self.horizontalLayoutWidget = QWidget(self.centralwidget)
self.horizontalLayoutWidget.setobjectName(u"horizontalLayoutWidget")
self.horizontalLayoutWidget.setGeometry(QRect(50,30,298,80))
self.horizontalLayout = QHBoxLayout(self.horizontalLayoutWidget)
self.horizontalLayout.setobjectName(u"horizontalLayout")
self.horizontalLayout.setContentsMargins(0,0)
self.label = QLabel(self.horizontalLayoutWidget)
self.label.setobjectName(u"label")
self.horizontalLayout.addWidget(self.label)
self.camera_comboBox = QComboBox(self.horizontalLayoutWidget)
self.camera_comboBox.setobjectName(u"camera_comboBox")
self.horizontalLayout.addWidget(self.camera_comboBox)
self.connect_btn = QPushButton(self.horizontalLayoutWidget)
self.connect_btn.setobjectName(u"connect_btn")
self.horizontalLayout.addWidget(self.connect_btn)
self.frame = qframe(self.centralwidget)
self.frame.setobjectName(u"frame")
self.frame.setGeometry(QRect(60,210,301,171))
sizePolicy = QSizePolicy(QSizePolicy.Expanding,QSizePolicy.Expanding)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.frame.sizePolicy().hasHeightForWidth())
self.frame.setSizePolicy(sizePolicy)
self.frame.setStyleSheet(u"background-color: rgb(0,0);")
self.horizontalLayout_2 = QHBoxLayout(self.frame)
self.horizontalLayout_2.setobjectName(u"horizontalLayout_2")
self.horizontalLayoutWidget_2 = QWidget(self.centralwidget)
self.horizontalLayoutWidget_2.setobjectName(u"horizontalLayoutWidget_2")
self.horizontalLayoutWidget_2.setGeometry(QRect(60,110,291,51))
self.horizontalLayout_3 = QHBoxLayout(self.horizontalLayoutWidget_2)
self.horizontalLayout_3.setobjectName(u"horizontalLayout_3")
self.horizontalLayout_3.setContentsMargins(0,0)
self.capture_btn = QPushButton(self.horizontalLayoutWidget_2)
self.capture_btn.setobjectName(u"capture_btn")
self.horizontalLayout_3.addWidget(self.capture_btn)
self.record_btn = QPushButton(self.horizontalLayoutWidget_2)
self.record_btn.setobjectName(u"record_btn")
self.horizontalLayout_3.addWidget(self.record_btn)
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QMenuBar(MainWindow)
self.menubar.setobjectName(u"menubar")
self.menubar.setGeometry(QRect(0,800,26))
MainWindow.setMenuBar(self.menubar)
self.statusbar = QStatusBar(MainWindow)
self.statusbar.setobjectName(u"statusbar")
MainWindow.setStatusBar(self.statusbar)
self.retranslateUi(MainWindow)
QMetaObject.connectSlotsByName(MainWindow)
# setupUi
def retranslateUi(self,MainWindow):
MainWindow.setwindowTitle(QCoreApplication.translate("MainWindow",u"MainWindow",None))
self.label.setText(QCoreApplication.translate("MainWindow",u"Device:",None))
self.connect_btn.setText(QCoreApplication.translate("MainWindow",u"Connect",None))
self.capture_btn.setText(QCoreApplication.translate("MainWindow",u"Capture",None))
self.record_btn.setText(QCoreApplication.translate("MainWindow",u"Record",None))
# retranslateUi
上面的代码是
的输出pyside2-uic mainwindow.ui -o MainWindow.py
这是mainwindow.ui的内容
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>MainWindow</class>
<widget class="QMainWindow" name="MainWindow">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>800</width>
<height>600</height>
</rect>
</property>
<property name="windowTitle">
<string>MainWindow</string>
</property>
<widget class="QWidget" name="centralwidget">
<widget class="QWidget" name="horizontalLayoutWidget">
<property name="geometry">
<rect>
<x>50</x>
<y>30</y>
<width>298</width>
<height>80</height>
</rect>
</property>
<layout class="QHBoxLayout" name="horizontalLayout">
<item>
<widget class="QLabel" name="label">
<property name="text">
<string>Device:</string>
</property>
</widget>
</item>
<item>
<widget class="QComboBox" name="camera_comboBox"/>
</item>
<item>
<widget class="QPushButton" name="connect_btn">
<property name="text">
<string>Connect</string>
</property>
</widget>
</item>
</layout>
</widget>
<widget class="qframe" name="frame">
<property name="geometry">
<rect>
<x>60</x>
<y>210</y>
<width>301</width>
<height>171</height>
</rect>
</property>
<property name="sizePolicy">
<sizepolicy hsizetype="Expanding" vsizetype="Expanding">
<horstretch>0</horstretch>
<verstretch>0</verstretch>
</sizepolicy>
</property>
<property name="styleSheet">
<string notr="true">background-color: rgb(0,0);</string>
</property>
<layout class="QHBoxLayout" name="horizontalLayout_2"/>
</widget>
<widget class="QWidget" name="horizontalLayoutWidget_2">
<property name="geometry">
<rect>
<x>60</x>
<y>110</y>
<width>291</width>
<height>51</height>
</rect>
</property>
<layout class="QHBoxLayout" name="horizontalLayout_3">
<item>
<widget class="QPushButton" name="capture_btn">
<property name="text">
<string>Capture</string>
</property>
</widget>
</item>
<item>
<widget class="QPushButton" name="record_btn">
<property name="text">
<string>Record</string>
</property>
</widget>
</item>
</layout>
</widget>
</widget>
<widget class="QMenuBar" name="menubar">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>800</width>
<height>26</height>
</rect>
</property>
</widget>
<widget class="QStatusBar" name="statusbar"/>
</widget>
<resources/>
<connections/>
</ui>
解决方法
QCamera需要一个QCameraViewfinder，它是一个小部件，可以显示QCamera捕获的信息，因此您无法将QFrame传递给它。
import sys
from PySide2.QtWidgets import QApplication,QMainWindow
from PySide2.QtMultimedia import QCamera,QCameraInfo
from PySide2.QtMultimediaWidgets import QCameraViewfinder
from MainWindow import Ui_MainWindow
class MainWindow(QMainWindow,Ui_MainWindow):
def __init__(self,*args,**kwargs):
super(MainWindow,self).__init__(*args,**kwargs)
self.setupUi(self)
for info in QCameraInfo.availableCameras():
self.camera_combobox.addItem(info.description(),info)
self.connect_btn.clicked.connect(self.connect_btn_clicked)
self.view_finder = QCameraViewfinder()
self.frame.layout().addWidget(self.view_finder)
def connect_btn_clicked(self):
info = self.camera_combobox.currentData()
self.camera = QCamera(info)
self.camera.setViewfinder(self.view_finder)
self.camera.start()
app = QApplication(sys.argv)
window = MainWindow()
window.show()
app.exec_()