python绘制饼状图qml显示示例2

运行需要安装pyside6。

pip install pyside6 -i https://pypi.douban.com/simple/

创建main.py文件，python代码注释如下：

import os
from pathlib import Path
import sys
from PySide6.QtCore import Property, Signal, Slot, Qt, QUrl
from PySide6.QtGui import QGuiApplication, QPen, QPainter, QColor
from PySide6.QtQml import qmlRegisterType
from PySide6.QtQuick import QQuickPaintedItem, QQuickView

class PieChart(QQuickPaintedItem):#定义PieChart类

    chartCleared = Signal()#清除chart信号
    nameChanged = Signal()
    chartView = Signal()#显示chart信号

    def __init__(self, parent=None):
        QQuickPaintedItem.__init__(self, parent)
        self._name = u''
        self._color = QColor()

    def paint(self, painter):#绘图
        pen = QPen(self.color, 2)
        painter.setPen(pen)
        painter.setRenderHints(QPainter.Antialiasing, True)
        painter.drawPie(self.boundingRect().adjusted(1, 1, -1, -1), 90 * 16, 290 * 16)

    @Property(QColor)
    def color(self):
        return self._color

    @color.setter
    def color(self, value):
        self._color = value

    @Property(str, notify=nameChanged)
    def name(self):
        return self._name

    @name.setter
    def name(self, value):
        self._name = value

    @Slot()  
    def clearChart(self):#清除chart
        self.color = Qt.transparent#设置透明色Qt.transparent
        self.update()
        self.chartCleared.emit()

    @Slot()  
    def chartView(self):#显示chart
        self.color = QColor("red")#设置颜色
        self.update()
        self.chartView.emit()

if __name__ == '__main__':
    app = QGuiApplication(sys.argv)

    qmlRegisterType(PieChart, 'Charts', 1, 0, 'PieChart')#注册类PieChart供qml使用

    view = QQuickView()
    view.setResizeMode(QQuickView.SizeRootObjectToView)
    qml_file = os.fspath(Path(__file__).resolve().parent / 'app.qml')
    view.setSource(QUrl.fromLocalFile(qml_file))
    if view.status() == QQuickView.Error:
        sys.exit(-1)
    view.show()
    res = app.exec()

    del view
    sys.exit(res)

创建app.qml界面文件，代码注释如下：

import Charts
import QtQuick

Item {
    width: 300; height: 200

    PieChart {
        id: aPieChart
        anchors.centerIn: parent
        width: 100; height: 100
        color: "red"

        onChartCleared: console.log("The chart has been cleared")
    }

    MouseArea {
        anchors.fill: parent
        onClicked: aPieChart.clearChart()//单击清除显示饼图
        onDoubleClicked: aPieChart.chartView()
        
    }

    Text {
        anchors {
            bottom: parent.bottom;
            horizontalCenter: parent.horizontalCenter;
            bottomMargin: 20
        }
        text: "单击任意位置清除图表\r\n双击任意位置显示图表"
    }
}