Python与QML加载交互

本示例展示了如何使用pyside加载 QML 文件，并与python代码交互。

main.py文件代码及注释如下：

import sysfrom pathlib import Pathfrom PySide6.QtCore import QObject, Slotfrom PySide6.QtGui import QGuiApplicationfrom PySide6.QtQml import QQmlApplicationEngine, QmlElementfrom PySide6.QtQuickControls2 import QQuickStyleQML_IMPORT_NAME = "io.qt.textproperties"QML_IMPORT_MAJOR_VERSION = 1@QmlElement#使用@QmlElement装饰器class Bridge(QObject):    #定义Bridge类    @Slot(str, result=str)    def getColor(self, s):        if s.lower() == "red":            return "#ef9a9a"        elif s.lower() == "green":            return "#a5d6a7"        elif s.lower() == "blue":            return "#90caf9"        else:            return "white"    @Slot(float, result=int)    def getSize(self, s):        size = int(s * 34)        if size <= 0:            return 1        else:            return size    @Slot(str, result=bool)    def getItalic(self, s):        if s.lower() == "italic":            return True        else:            return False    @Slot(str, result=bool)    def getBold(self, s):        if s.lower() == "bold":            return True        else:            return False    @Slot(str, result=bool)    def getUnderline(self, s):        if s.lower() == "underline":            return True        else:            return Falseif __name__ == '__main__':    app = QGuiApplication(sys.argv)    QQuickStyle.setStyle("Material")    engine = QQmlApplicationEngine()    qml_file = Path(__file__).parent / 'view.qml'#获取当前目录的路径，然后添加qml文件    engine.load(qml_file)#加载qml文件    if not engine.rootObjects():        sys.exit(-1)    sys.exit(app.exec())

view.qml文件代码及注释如下：

import QtQuick 2.0import QtQuick.Layouts 1.11import QtQuick.Controls 2.1import QtQuick.Window 2.1import QtQuick.Controls.Material 2.1import io.qt.textproperties 1.0ApplicationWindow {    id: page    width: 800    height: 400    visible: true    Material.theme: Material.Dark    Material.accent: Material.Red    Bridge {//将信号连接到python中的Bridge类        id: bridge    }    GridLayout {//网格布局        id: grid        columns: 2//2列        rows: 3//3行        ColumnLayout {//列布局            spacing: 2//元素间隔            Layout.columnSpan: 1//此属性允许您指定GridLayout中项目的列跨度。默认值为1。            Layout.preferredWidth: 400//此属性保存布局中项目的首选宽度                        Text {                id: leftlabel                Layout.alignment: Qt.AlignHCenter//水平居中对齐                color: "white"                font.pointSize: 16                text: "你好Pyside6"                Layout.preferredHeight: 100                Material.accent: Material.Green            }            RadioButton {                id: italic                Layout.alignment: Qt.AlignLeft//左居中对齐                text: "Italic"                onToggled: {//选择触发事件                    //函数getItalic()返回bool值给leftlabel.font.italic设置字体是否为斜体                    leftlabel.font.italic = bridge.getItalic(italic.text)                    //函数getBold()返回bool值给leftlabel.font.bold设置字体是否是粗体                    leftlabel.font.bold = bridge.getBold(italic.text)                    //函数getUnderline()返回bool值给leftlabel.font.underline设置字体是否右下划线                    leftlabel.font.underline = bridge.getUnderline(italic.text)                }            }            RadioButton {                id: bold                Layout.alignment: Qt.AlignLeft                text: "Bold"                onToggled: {                    leftlabel.font.italic = bridge.getItalic(bold.text)                    leftlabel.font.bold = bridge.getBold(bold.text)                    leftlabel.font.underline = bridge.getUnderline(bold.text)                }            }            RadioButton {                id: underline                Layout.alignment: Qt.AlignLeft                text: "Underline"                onToggled: {                    leftlabel.font.italic = bridge.getItalic(underline.text)                    leftlabel.font.bold = bridge.getBold(underline.text)                    leftlabel.font.underline = bridge.getUnderline(underline.text)                }            }            RadioButton {                id: noneradio                Layout.alignment: Qt.AlignLeft                text: "None"                checked: true                onToggled: {                    leftlabel.font.italic = bridge.getItalic(noneradio.text)                    leftlabel.font.bold = bridge.getBold(noneradio.text)                    leftlabel.font.underline = bridge.getUnderline(noneradio.text)                }            }        }        ColumnLayout {            id: rightcolumn            spacing: 2            Layout.columnSpan: 1            Layout.preferredWidth: 400            Layout.preferredHeight: 400            Layout.fillWidth: true            RowLayout {                Layout.alignment: Qt.AlignVCenter | Qt.AlignHCenter                Button {                    id: red                    text: "Red"                    highlighted: true                    Material.accent: Material.Red                    onClicked: {                        //函数getColor()返回颜色赋值给leftlabel.color                        leftlabel.color = bridge.getColor(red.text)                    }                }                Button {                    id: green                    text: "Green"                    highlighted: true                    Material.accent: Material.Green                    onClicked: {                        leftlabel.color = bridge.getColor(green.text)                    }                }                Button {                    id: blue                    text: "Blue"                    highlighted: true                    Material.accent: Material.Blue                    onClicked: {                        leftlabel.color = bridge.getColor(blue.text)                    }                }                Button {                    id: nonebutton                    text: "None"                    highlighted: true                    Material.accent: Material.BlueGrey                    onClicked: {                        leftlabel.color = bridge.getColor(nonebutton.text)                    }                }            }            RowLayout {                Layout.fillWidth: true                Layout.alignment: Qt.AlignVCenter | Qt.AlignHCenter                Text {                    id: rightlabel                    color: "white"                    Layout.alignment: Qt.AlignLeft                    text: "Font size"                    Material.accent: Material.White                }                Slider {                    width: rightcolumn.width*0.6                    Layout.alignment: Qt.AlignRight                    id: slider                    value: 0.5                    onValueChanged: {                        //函数getSize()返回int值，赋值给leftlabel.font.pointSize改变字体大小                        leftlabel.font.pointSize = bridge.getSize(value)                    }                }            }        }    }}

将main.py与view.qml放到同一文件夹，运行main.py，显示如下：