如何继承 QPointF 并设置自定义属性？

Question

在我的图表中，我需要在每个 QPointF 中存储很多信息，但是当我对 QPointF 进行子类化时，它似乎没有任何效果，有人可以给我好的解决方案或想法吗？

代码为：

from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtPrintSupport import *
from PyQt5.QtChart import *
import random

class MyPoint(QPointF):
    def __init__(self, *args):
        super().__init__(*args)

    def set_name(self, name):
        self.name = name

    def set_info(self, info):
        self.info = info


class DemoChar(QChartView):
    def __init__(self):
        super().__init__()
        self.setRenderHint(QPainter.Antialiasing)
        self.chart = QChart()
        self.chart.setTitle('Demo')
        self.chart.setAnimationOptions(QChart.SeriesAnimations)
        self.setChart(self.chart)
        self.lineItem = QGraphicsLineItem(self.chart)

        series = QLineSeries(name="random serie")
        series.setPointsVisible(True)
        series.clicked.connect(self.on_click)

        self.series = series

        for i in range(20):
            #series << QPointF(0.1 * i, random.uniform(-10, 10))
            pt = MyPoint( 0.1 * i, random.uniform(-10, 10) )
            pt.set_name(str(pt))
            pt.set_info(str(random.randint(1, 100)))
            series << pt

        self.chart.addSeries(series)
        self.chart.createDefaultAxes()

    def on_click(self, pt):
        one_pt = self.series.pointsVector()[0]
        print(one_pt)
       # print(one_pt.name)  #the point have no name, info attribute

app = QApplication([])
demo = DemoChar()
demo.show()
app.exec()

Answer 1

当您将 QPointF 传递给 QLineSeries 时，使用的复制构造函数只复制 x 和 y 值，也就是说，它不复制对象，只复制一些属性。

因此，与其实现自定义 QPointF，不如使用 QVXYModelMapper 实现映射到 QLineSeries 的模型：

import random

from PyQt5.QtCore import pyqtSlot, QPointF, Qt
from PyQt5.QtGui import QPainter, QStandardItem, QStandardItemModel
from PyQt5.QtWidgets import QApplication
from PyQt5.QtChart import QChart, QChartView, QLineSeries, QVXYModelMapper


class CustomModel(QStandardItemModel):
    def add_point(self, pt, name="", info=""):
        items = []
        for value in (pt.x(), pt.y(), name, info):
            it = QStandardItem()
            it.setData(value, Qt.DisplayRole)
            items.append(it)
        self.appendRow(items)

    def get_data(self, row):
        if 0 <= row < self.rowCount():
            pt = QPointF(
                self.item(row, 0).data(Qt.DisplayRole),
                self.item(row, 1).data(Qt.DisplayRole),
            )
            name = self.item(row, 2).data(Qt.DisplayRole)
            info = self.item(row, 3).data(Qt.DisplayRole)
            return pt, name, info


class DemoChar(QChartView):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setRenderHint(QPainter.Antialiasing)
        self.chart = QChart()
        self.chart.setTitle("Demo")
        self.chart.setAnimationOptions(QChart.SeriesAnimations)
        self.setChart(self.chart)

        self.model = CustomModel()
        self.series = QLineSeries(name="random serie")
        self.series.setPointsVisible(True)
        self.series.clicked.connect(self.on_click)

        self.mapper = QVXYModelMapper(xColumn=0, yColumn=1)
        self.mapper.setModel(self.model)
        self.mapper.setSeries(self.series)

        for i in range(20):
            pt = QPointF(0.1 * i, random.uniform(-10, 10))
            name = "name-{}".format(i)
            info = str(random.randint(1, 100))
            self.model.add_point(pt, name, info)

        self.chart.addSeries(self.series)
        self.chart.createDefaultAxes()

    @pyqtSlot(QPointF)
    def on_click(self, pt):
        # first point
        index = 0
        value = self.model.get_data(index)
        if value is not None:
            pt, name, info = value
            print(pt, name, info)


def main(args):
    app = QApplication(args)
    demo = DemoChar()
    demo.show()
    ret = app.exec()


if __name__ == "__main__":
    import sys

    sys.exit(main(sys.argv))

如何继承 QPointF 并设置自定义属性？

How to subclass QPointF and set custom attribute?

python

pyqt

pyqt5

qtcharts