Raspberry 上的 PyQt5：不显示 QTWidgets 的背景颜色
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【中文标题】Raspberry 上的 PyQt5：不显示 QTWidgets 的背景颜色【英文标题】：PyQt5 on Raspbian: Background color of QWidgets is not displayed 【发布时间】：2019-08-24 11:29:25 【问题描述】：我已经在运行 Raspbian Buster 的 Raspberry Pi 3B+ 上编译并安装了 PyQt5，如 here 所述。花了几个小时，但它奏效了。之后我上传了我的简单 PyQt 示例程序，其中包含 2 个文件（main.py 和 mainwindow.ui）。
为QProgressBar 和QPushButton 设置的红色背景颜色在我的运行Ubuntu 18.04 LTS 的PC 上显示为不同深浅的红色(?)，但在Raspberry Pi 上根本不显示。
Raspbian Buster 上的终端输出：
libEGL warning: DRI2: failed to authenticate
qt5ct: using qt5ct plugin
qt5ct: D-Bus global menu: no
Ubuntu 18.04 LTS 上的屏幕截图：
Raspbian Buster 的屏幕截图：
为什么 Raspbian Buster 上不显示红色背景色？
main.py
import sys
from pathlib import Path
from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5.QtGui import QColor
from PyQt5.uic import loadUi
class MainWindow(QMainWindow):
def __init__(self, parent=None):
super().__init__(parent)
ui_file = (Path(__file__).parent / "mainwindow.ui").resolve()
loadUi(ui_file, self)
self.progressBar.setStyleSheet(f"background-color: QColor('red').name()")
def main():
app = QApplication(sys.argv)
main_window = MainWindow()
main_window.show()
sys.exit(app.exec_())
if __name__ == "__main__":
main()
mainwindow.ui
<?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>200</height>
</rect>
</property>
<property name="windowTitle">
<string>MainWindow</string>
</property>
<property name="locale">
<locale language="English" country="UnitedKingdom"/>
</property>
<widget class="QWidget" name="centralwidget">
<layout class="QGridLayout" name="gridLayout_2">
<item row="0" column="0">
<layout class="QGridLayout" name="gridLayout">
<item row="0" column="0">
<widget class="QProgressBar" name="progressBar">
<property name="value">
<number>0</number>
</property>
</widget>
</item>
<item row="0" column="1">
<widget class="QPushButton" name="pushButton">
<property name="minimumSize">
<size>
<width>200</width>
<height>0</height>
</size>
</property>
<property name="styleSheet">
<string notr="true">background-color: red;</string>
</property>
<property name="text">
<string>Button</string>
</property>
</widget>
</item>
</layout>
</item>
</layout>
</widget>
<widget class="QMenuBar" name="menubar">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>800</width>
<height>28</height>
</rect>
</property>
</widget>
<widget class="QStatusBar" name="statusbar"/>
</widget>
<resources/>
<connections/>
</ui>
设置export QT_DEBUG_PLUGINS=1后Raspbian Buster的终端输出：
QFactoryLoader::QFactoryLoader() checking directory path "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqeglfs.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqeglfs.so, metadata=
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData":
"Keys": [
"eglfs"
]
,
"className": "QEglFSIntegrationPlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("eglfs")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqlinuxfb.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqlinuxfb.so, metadata=
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData":
"Keys": [
"linuxfb"
]
,
"className": "QLinuxFbIntegrationPlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("linuxfb")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqminimal.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqminimal.so, metadata=
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData":
"Keys": [
"minimal"
]
,
"className": "QMinimalIntegrationPlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqminimalegl.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqminimalegl.so, metadata=
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData":
"Keys": [
"minimalegl"
]
,
"className": "QMinimalEglIntegrationPlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("minimalegl")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqoffscreen.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqoffscreen.so, metadata=
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData":
"Keys": [
"offscreen"
]
,
"className": "QOffscreenIntegrationPlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqvnc.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqvnc.so, metadata=
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData":
"Keys": [
"vnc"
]
,
"className": "QVncIntegrationPlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("vnc")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqxcb.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqxcb.so, metadata=
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
"MetaData":
"Keys": [
"xcb"
]
,
"className": "QXcbIntegrationPlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/platforms" ...
loaded library "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqxcb.so"
loaded library "Xcursor"
QFactoryLoader::QFactoryLoader() checking directory path "/usr/lib/arm-linux-gnueabihf/qt5/plugins/xcbglintegrations" ...
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/xcbglintegrations/libqxcb-egl-integration.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/xcbglintegrations/libqxcb-egl-integration.so, metadata=
"IID": "org.qt-project.Qt.QPA.Xcb.QXcbGlIntegrationFactoryInterface.5.5",
"MetaData":
"Keys": [
"xcb_egl"
]
,
"className": "QXcbEglIntegrationPlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("xcb_egl")
QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/xcbglintegrations" ...
loaded library "/usr/lib/arm-linux-gnueabihf/qt5/plugins/xcbglintegrations/libqxcb-egl-integration.so"
libEGL warning: DRI2: failed to authenticate
QFactoryLoader::QFactoryLoader() checking directory path "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platformthemes" ...
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platformthemes/libqgtk2.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platformthemes/libqgtk2.so, metadata=
"IID": "org.qt-project.Qt.QPA.QPlatformThemeFactoryInterface.5.1",
"MetaData":
"Keys": [
"gtk2"
]
,
"className": "QGtk2ThemePlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("gtk2")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platformthemes/libqgtk3.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platformthemes/libqgtk3.so, metadata=
"IID": "org.qt-project.Qt.QPA.QPlatformThemeFactoryInterface.5.1",
"MetaData":
"Keys": [
"gtk3"
]
,
"className": "QGtk3ThemePlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("gtk3")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platformthemes/libqt5ct.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platformthemes/libqt5ct.so, metadata=
"IID": "org.qt-project.Qt.QPA.QPlatformThemeFactoryInterface.5.1",
"MetaData":
"Keys": [
"qt5ct"
]
,
"className": "Qt5CTPlatformThemePlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("qt5ct")
QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/platformthemes" ...
loaded library "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platformthemes/libqt5ct.so"
qt5ct: using qt5ct plugin
QFactoryLoader::QFactoryLoader() checking directory path "/usr/lib/arm-linux-gnueabihf/qt5/plugins/styles" ...
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libbb10styleplugin.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libbb10styleplugin.so, metadata=
"IID": "org.qt-project.Qt.QStyleFactoryInterface",
"MetaData":
"Keys": [
"bb10bright",
"bb10dark"
]
,
"className": "QBB10StylePlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("bb10bright", "bb10dark")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libqcleanlooksstyle.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libqcleanlooksstyle.so, metadata=
"IID": "org.qt-project.Qt.QStyleFactoryInterface",
"MetaData":
"Keys": [
"cleanlooks"
]
,
"className": "QCleanlooksStylePlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("cleanlooks")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libqgtk2style.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libqgtk2style.so, metadata=
"IID": "org.qt-project.Qt.QStyleFactoryInterface",
"MetaData":
"Keys": [
"gtk2"
]
,
"className": "QGtk2StylePlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("gtk2")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libqmotifstyle.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libqmotifstyle.so, metadata=
"IID": "org.qt-project.Qt.QStyleFactoryInterface",
"MetaData":
"Keys": [
"motif",
"cde"
]
,
"className": "QMotifStylePlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("motif", "cde")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libqplastiquestyle.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libqplastiquestyle.so, metadata=
"IID": "org.qt-project.Qt.QStyleFactoryInterface",
"MetaData":
"Keys": [
"plastique"
]
,
"className": "QPlastiqueStylePlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("plastique")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libqt5ct-style.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libqt5ct-style.so, metadata=
"IID": "org.qt-project.Qt.QStyleFactoryInterface",
"MetaData":
"Keys": [
"qt5ct-style"
]
,
"className": "Qt5CTStylePlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("qt5ct-style")
QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/styles" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforminputcontexts" ...
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforminputcontexts/libcomposeplatforminputcontextplugin.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforminputcontexts/libcomposeplatforminputcontextplugin.so, metadata=
"IID": "org.qt-project.Qt.QPlatformInputContextFactoryInterface.5.1",
"MetaData":
"Keys": [
"compose",
"xim"
]
,
"className": "QComposePlatformInputContextPlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("compose", "xim")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforminputcontexts/libibusplatforminputcontextplugin.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforminputcontexts/libibusplatforminputcontextplugin.so, metadata=
"IID": "org.qt-project.Qt.QPlatformInputContextFactoryInterface.5.1",
"MetaData":
"Keys": [
"ibus"
]
,
"className": "QIbusPlatformInputContextPlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("ibus")
QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/platforminputcontexts" ...
loaded library "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforminputcontexts/libcomposeplatforminputcontextplugin.so"
loaded library "/usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libqt5ct-style.so"
loaded library "/usr/lib/arm-linux-gnueabihf/qt5/plugins/styles/libqgtk2style.so"
Cannot load library gtk-x11-2.0: (gtk-x11-2.0: Kann die Shared-Object-Datei nicht öffnen: Datei oder Verzeichnis nicht gefunden)
qt5ct: D-Bus global menu: no
QFactoryLoader::QFactoryLoader() checking directory path "/usr/lib/arm-linux-gnueabihf/qt5/plugins/iconengines" ...
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/iconengines/libqsvgicon.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/iconengines/libqsvgicon.so, metadata=
"IID": "org.qt-project.Qt.QIconEngineFactoryInterface",
"MetaData":
"Keys": [
"svg",
"svgz",
"svg.gz"
]
,
"className": "QSvgIconPlugin",
"debug": false,
"version": 330499
Got keys from plugin meta data ("svg", "svgz", "svg.gz")
QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/iconengines" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/lib/arm-linux-gnueabihf/qt5/plugins/accessible" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/accessible" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/lib/arm-linux-gnueabihf/qt5/plugins/accessiblebridge" ...
QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/accessiblebridge" ...
【问题讨论】：
当您从终端运行文件时，您会收到错误消息吗？在您的 raspbian 和 ubuntu 中，print(app.style().metaObject().className()) 的输出是什么？
在 Ubuntu 上没有终端输出，但在 Raspbian 上显示以下内容。 ``` libEGL 警告：DRI2：无法验证 qt5ct：使用 qt5ct 插件 qt5ct：D-Bus 全局菜单：否 ```Python 命令在 Ubuntu 和 Raspbian 上都不会导致输出。
export QT_DEBUG_PLUGINS=1python your_script.py的输出是什么
@eyllanesc 设置export QT_DEBUG_PLUGINS=1后有很多终端输出（见上）。
【参考方案1】：
我今天一直在与类似的问题作斗争（这就是我找到您的帖子的方式）。要摆脱 libEGL 警告，请运行 raspi-config 并从 Advanced Options->GL Driver 中选择“Full KMS”选项（然后重新启动）。不过，这可能无法解决您的样式问题 - 我看到 Pi（我的目标系统）和我的 Linux Mint 开发系统之间的样式差异。
【讨论】：
【参考方案2】：我也有类似的问题，按照下面的方式运行就可以解决了。
sudo python3.7 name.py
我想 IDE 或当前登录的用户需要一些权限。 虽然颜色仍然比 Windows 和 Ubuntu 更不透明。
【讨论】：
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