QML 的 PySide6 后端是否有更简洁的方法？

Question

您好，我正在使用 Model class 为列表和组合框提供项目。问题是我每次都对每个元素使用 setContextProperty() 函数。我正在寻找一种解决方案，其中所有元素（列表和组合框）都使用相同的 ContextProperty。此外，我猜 JSON 文件可以动态加载，而不是一开始就加载所有文件。

main.py

class Model(QAbstractListModel, QObject):
    """ it reads JSON file, that is given as argument,
    and creates the model"""

if __name__ == "__main__":
    app = QGuiApplication(sys.argv)
    engine = QQmlApplicationEngine()

    model1 = Model("file1.json")
    model2 = Model("file2.json")
    model3 = Model("file3.json")
    model4 = Model("file4.json")
    model5 = Model("file5.json")

    engine.rootContext().setContextProperty("model1", model1)
    engine.rootContext().setContextProperty("model2", model2)
    engine.rootContext().setContextProperty("model3", model3)
    engine.rootContext().setContextProperty("model4", model4)
    engine.rootContext().setContextProperty("model5", model5)

    engine.rootContext().setContextProperty("applicationDirPath", os.path.dirname(__file__))
    engine.load(os.path.join(os.path.dirname(__file__), "main.qml"))

    if not engine.rootObjects():
        sys.exit(-1)
    sys.exit(app.exec())

Answer 1

您可以创建一个将所有模型公开为属性列表的 QObject，然后使用 Repeater 动态创建组合框。

以下为演示：

import os
import sys
from pathlib import Path

from PySide6.QtCore import Property, QCoreApplication, QObject, Qt, QUrl, Signal
from PySide6.QtGui import QGuiApplication, QStandardItem, QStandardItemModel
from PySide6.QtQml import QQmlApplicationEngine

CURRENT_DIRECTORY = Path(__file__).resolve().parent


class Model(QStandardItemModel):
    def __init__(self, values, parent=None):
        super().__init__(parent)
        for value in values:
            item = QStandardItem(value)
            self.appendRow(item)


class Manager(QObject):
    models_changed = Signal(name="modelsChanged")

    def __init__(self, parent=None):
        super().__init__(parent)
        self._models = []

    @Property("QVariantList", notify=models_changed)
    def models(self):
        return self._models

    def append_model(self, model):
        self._models.append(model)
        self.models_changed.emit()


def main():
    app = QGuiApplication(sys.argv)

    manager = Manager(app)

    manager.append_model(Model(["item11", "item12", "item13"]))
    manager.append_model(Model(["item21", "item22", "item23"]))
    manager.append_model(Model(["item31", "item32", "item33"]))
    manager.append_model(Model(["item41", "item42", "item43"]))

    engine = QQmlApplicationEngine()

    context = engine.rootContext()
    context.setContextProperty("applicationDirPath", os.fspath(CURRENT_DIRECTORY))
    context.setContextProperty("managerModel", manager)

    filename = os.fspath(CURRENT_DIRECTORY / "main.qml")
    url = QUrl.fromLocalFile(filename)

    def handle_object_created(obj, obj_url):
        if obj is None and url == obj_url:
            QCoreApplication.exit(-1)

    engine.objectCreated.connect(handle_object_created, Qt.QueuedConnection)
    engine.load(url)

    sys.exit(app.exec())


if __name__ == "__main__":
    main()

import QtQuick
import QtQuick.Controls
import QtQuick.Layouts

ApplicationWindow {
    width: 640
    height: 480
    visible: true

    ColumnLayout {
        anchors.centerIn: parent

        Repeater {
            id: repeater

            model: managerModel.models

            ComboBox {
                model: modelData
                textRole: "display"
                Layout.fillWidth: true
            }

        }

    }

}

_{旁注：QAbstractListModel 是一个 QObject，因此双重继承是无用的，因此您应该将其更改为：class Model(QAbstractListModel):}

QML 的 PySide6 后端是否有更简洁的方法？

Is there a cleaner way for backend in PySide6 for QML?

python

qt

qml

pyside6