使用python在qml窗口中绘制数据时获取空图

Question

我试图使用python脚本在qt窗口(qml)中绘制数据(存储在csv文件中)。我正试着跟踪这个link。下面是我尝试过的代码：

main.qml

import QtQuick
import QtQuick.Window
import QtQuick.Controls
import './imports/Plot_Test'
import QtCharts 2.14
Window {
    width: plot_rect.width
    height: plot_rect.height

    visible: true
    title: "Plot_Test"

    Rectangle {
        id: plot_rect
        width: 1296
        height: 730
        color: "#6e9ccc"


        ChartView {
            id: spline_view
            anchors.left: parent.left
            anchors.right: parent.right
            anchors.top: parent.top
            anchors.bottom: parent.bottom
            anchors.bottomMargin: 20
            anchors.topMargin: 20
            anchors.rightMargin: 20
            anchors.leftMargin: 20
            SplineSeries{
                id: plot
                name: "xyz"
                axisX: ValueAxis {
                    color: "#1c2b95"
                    gridLineColor: "#6e9ccc"
                    min: 0
                    max: 10
                    tickCount: 6
                }
                axisY: ValueAxis {
                    color: "#1c2b95"
                    gridLineColor: "#6e9ccc"
                    min: 0
                    max: 30000
                    tickCount: 6
                }
                XYPoint {
                    x: 1
                    y: 10000
                }
                XYPoint {
                    x: 2
                    y: 12000
                }
        }

        Component.onCompleted:  {
            console.log("This is main.QML")
            // var serie = spline_view.createSeries(ChartView.SeriesTypeSpline,"Random",axisX,axisY)
                }
        }

    Connections {
        target: plotter
        function onGetSeries(series){
           plot.XYSeries(series)
       }
    }
    }
}

main.py

# This Python file uses the following encoding: utf-8
import os
from pathlib import Path
import sys

from PySide6.QtCore import QCoreApplication, Qt, QUrl
from PySide6.QtWidgets import QApplication
from PySide6.QtQml import QQmlApplicationEngine
from PySide6.QtCharts import QChartView

import data_plot

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


def main():
    app = QApplication(sys.argv)
    helper = data_plot.Helper()
    # provider.pointsChanged.connect(helper.replace_points)
    engine = QQmlApplicationEngine()
    engine.rootContext().setContextProperty('plotter', helper)
    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()

data_plot.py

from email import policy
import pandas as pd
from PySide6.QtCore import QPointF, QObject, Signal, Slot
from PySide6.QtCharts import QChart, QChartView, QSplineSeries, QValueAxis, QXYSeries, QAbstractSeries
from PySide6 import QtCore

class Helper(QObject):
    getSeries = Signal(list)

    def __init__(self, parent=None):
        QObject.__init__(self)

    @Slot(QSplineSeries)
    def update_series(self, series):

        series.replace(self.generate_points())

    @Slot(list)
    def generate_points(self):
        points = []
        df = pd.read_csv('NK_Heavy.csv')
        x = df['x']
        for i in range(len(x)):
            point = QPointF(i, x[i])
            points.append(point)
        self.getSeries.emit(points)
        return points

我试图访问qml元素(在本例中，splineseries: plot )，但是样条系列的XYPoint/XYSeries元素仍然没有更新。谁能指出我在这里的错误是什么，我如何解决它。谢谢

编辑 Ok，让我重新整理我的问题。如何在我的python代码中调用spline_view (它是chartview对象的id，或者plot是chartview文件中的splineseries对象的id )，这样我就可以在python中自己添加序列/数据。

Answer 1

我在网上查了一下，发现了我的错误，我试图从python调用函数，但我没有把任何论据传递给它。以下是完整的解决方案：

data_plot.py

import pandas as pd
from PySide6.QtCore import QObject, QPointF, Slot
from PySide6.QtCharts import QChartView, QChart, QAbstractSeries, QSplineSeries, QValueAxis
from PySide6 import QtGui

class DataModel(QObject):
    @Slot(QSplineSeries)
    def fill_serie(self, plot):
        self.df = pd.read_csv('gvk_normal_minus_ambient.csv')
        x = self.df['x']
        count = 0
        for i in range(0,len(x)):
            point = QPointF(count, x[i])
            # point =  x[i]
            plot.append(point)
            count += 1
        plot.setProperty("color", QtGui.QBrush(QtGui.QColor("red")))
        plot.setProperty("borderWidth", 4.0)

    @Slot(QValueAxis)
    def min_yaxis(self, yaxis):
        yaxis.setProperty('min', min(self.df['x']))
    
    @Slot(QValueAxis)
    def max_yaxis(self, yaxis):
        yaxis.setProperty('max', max(self.df['x']))

    @Slot(QValueAxis)
    def min_xaxis(self, xaxis):
        xaxis.setProperty('min', 0)
        xaxis.setProperty('tickInterval', 10)

    @Slot(QValueAxis)
    def max_xaxis(self, xaxis):
        xaxis.setProperty('max', 30)

main.qml

Component.onCompleted:  {
        console.log("This is main.QML")
        var plot = spline_view.createSeries(ChartView.SeriesTypeSpline,"Random",axisX,axisY)
        plotter.fill_serie(plot)
        var ymax = plotter.max_yaxis(axisY)
        var ymin = plotter.min_yaxis(axisY)
        var xmax = plotter.max_xaxis(axisX)
        var xmin = plotter.min_xaxis(axisX)
        
            }

以上部分，我改变了我的旧main.py，并找到了答案。