python - 使用 QtQuick.Controls 中的任何内容都会引发 protected 模块错误

Question

当我尝试启动程序时出现这些错误:

plugin cannot be loaded for module, cannot install type into protected module

平台:
python 3.8
PyQt5 5.15.0
Visual Studio 社区 2019
window 10 专业版 1909
主 python 文件 (整个事情几乎就是这里的例子: https://codeloop.org/pyqt5-creating-first-window/)

import numpy
import os
import sys
from PyQt5.QtQml import QQmlApplicationEngine
from PyQt5.QtWidgets import QApplication

def main():
    app =QApplication(sys.argv)
    engine = QQmlApplicationEngine()
    engine.load(os.path.join(os.path.dirname(__file__), "MainApp.qml"))
 
 
    if not engine.rootObjects():
        return -1
 
    return app.exec_()

if __name__ == '__main__':
    main(); 

对应的 QML 文件“ MainApp.qml ”:

import QtQuick.Window 2.15
import QtQuick.Controls 2.15
import QtQuick 2.15

Window {
 
    visible:true
    width:600
    height:400
    color:"yellow"
    title: "PyQt5 QML Window"
 
    Button {
        text: "Something"
        anchors.horizontalCenter: parent.horizontalCenter
        anchors.verticalCenter: parent.verticalCenter
    }
 
 
}

不使用 QtQuick.Controls 中的任何东西，它就可以工作，但是一旦我添加按钮，它就会生成以下错误:

QQmlApplicationEngine failed to load component
file:///C:/Users/elano/Source/Repos/Projekt-1-SS2020/Projekt-1-SS2020/MainApp.qml:15:5: Type Button unavailable
file:///C:/Users/elano/vpqt/lib/site-packages/PyQt5/Qt/qml/QtQuick/Controls.2/qmldir: plugin cannot be loaded for module "QtQuick.Controls": Cannot install type 'VerticalHeaderView' into protected module 'QtQuick.Controls' version '2'
<Unknown File>: Cannot install type 'HorizontalHeaderView' into protected module 'QtQuick.Controls' version '2'
<Unknown File>: Cannot install element 'SplitHandle' into protected module 'QtQuick.Controls' version '2'
...

它尝试查找的文件 (qmldir) 确实存在，并且包含以下内容:

module QtQuick.Controls
plugin qtquickcontrols2plugin
classname QtQuickControls2Plugin
depends QtQuick.Templates 2.5
designersupported

有谁知道这里发生了什么？是否需要更多信息？

Answer 1

好吧，现在我觉得自己很愚蠢。我已经在我的代码中有我的答案，但由于它没有让 Pyside2 工作，我把它注释掉了......
问题是，环境变量设置不正确。在我的主文件中的导入语句之后添加它修复了它:

dirname = os.path.dirname(PyQt5.__file__)
plugin_path = os.path.join(dirname, 'plugins', 'platforms')
os.environ['QML2_IMPORT_PATH'] = os.path.join(dirname, 'qml')

我发现没有任何教程提到过这一点。伟大的。