如何从 PySide 访问 QML\QtQuick 控件？

Question

我正在尝试从启动 QQmlApplication 引擎的 python 文件访问 FileDialog 控件，以便检索文件路径属性。我已经在 .qml 文件中设置了一个信号，但是我无法通过 python 文件中的 id 访问文件对话框来设置插槽。 application.pyreturnsNone中的findChild方法。这是代码：

application.py

import sys
from PySide2.QtGui import QGuiApplication
from PySide2.QtQml import QQmlApplicationEngine, QQmlFileSelector

sys_argv = sys.argv
sys_argv += ['--style', 'material']
app = QGuiApplication(sys_argv)

window = QQmlApplicationEngine()
window.load("QML/main.qml")

fileDialog = window.findChild(QQmlFileSelector, "fileDialog")
print(fileDialog)

app.exec_()

Page1.qml

import QtQuick 2.9
import QtQuick.Controls 2.2
import QtQuick.Dialogs 1.2

Page {
    width: 600
    height: 400

    header: Label {
        text: qsTr("Prepare Data")
        horizontalAlignment: Text.AlignHCenter
        font.pixelSize: Qt.application.font.pixelSize * 2
        padding: 10
    }

    Button {
        text: qsTr("Load data")
        anchors.centerIn: parent
        onClicked: fileDialog.visible = true
        padding: 10
    }

    signal folderSelected()

    FileDialog {
        id: fileDialog
        selectFolder: true
        title: qsTr("Select the data directory")
        folder: shortcuts.home
        onAccepted: {
            parent.folderSelected()
        }
    }
}

main.qml

import QtQuick 2.0
import QtQuick.Controls 2.12
import QtQuick.Controls.Material 2.12

ApplicationWindow{
    visible: true
    title: qsTr("Main window")
    width: 1000
    height: 800

    Material.theme: Material.Light
    Material.accent: Material.Orange

    SwipeView {
        id: swipeView
        anchors.fill: parent

        Page1 {
        }

        Page2 {
        }

        Page3 {
        }

    }
}

Answer 1

在部分解释 将引用推送到 QML 如何从 QML 更新一些 python 对象，该方法是推荐的方法Qt，它是现在应该使用的那个。使用您当前的方法，您需要建立一个在许多情况下可能会出现问题的对象名称。

所以解决方案是创建一个我们导出到 QML 的 QObject 并更新 q属性，这将发出一个信号，表明我们连接到一个插槽，我们可以在其中执行我们想要的逻辑。另一方面，FileDialog returns a url，所以属性必须是 QUrl:

main.qml

import os
import sys
from PySide2 import QtCore, QtGui, QtQml

class FileManager(QtCore.QObject):
    file_url_Changed = QtCore.Signal(QtCore.QUrl)

    def __init__(self, parent=None):
        super(FileManager, self).__init__(parent)
        self._file_url = QtCore.QUrl()

    def get_file_url(self):
        return self._file_url

    def set_file_url(self, file_url):
        if self._file_url != file_url:
            self._file_url = file_url
            self.file_url_Changed.emit(self._file_url)

    file_url = QtCore.Property(QtCore.QUrl, fget=get_file_url, fset=set_file_url, notify=file_url_Changed)

@QtCore.Slot(QtCore.QUrl)
def on_file_url_changed(file_url):
    print(file_url.toLocalFile())

if __name__ == '__main__':
    sys.argv += ['--style', 'material']
    app = QtGui.QGuiApplication(sys.argv)

    file_manager = FileManager()
    file_manager.file_url_Changed.connect(on_file_url_changed)

    engine = QtQml.QQmlApplicationEngine()
    engine.rootContext().setContextProperty("file_manager", file_manager)
    file = os.path.join(os.path.dirname(os.path.realpath(__file__)), "QML", "main.qml")
    engine.load(QtCore.QUrl.fromLocalFile(file))
    if not engine.rootObjects():
        sys.exit(-1)
    sys.exit(app.exec_())

Page1.qml

import QtQuick 2.9
import QtQuick.Controls 2.2
import QtQuick.Dialogs 1.2

Page {
    width: 600
    height: 400

    header: Label {
        text: qsTr("Prepare Data")
        horizontalAlignment: Text.AlignHCenter
        font.pixelSize: Qt.application.font.pixelSize * 2
        padding: 10
    }

    Button {
        text: qsTr("Load data")
        anchors.centerIn: parent
        onClicked: fileDialog.visible = true
        padding: 10
    }

    FileDialog {
        id: fileDialog
        selectFolder: true
        title: qsTr("Select the data directory")
        folder: shortcuts.home
        onAccepted: {
            file_manager.file_url = fileDialog.fileUrl // <---
        }
    }
}

如何从 PySide 访问 QML\QtQuick 控件？

How to access QML\QtQuick controls from PySide?

python

qml

pyside2