如何在自定义小部件中显示QChartView？

from PyQt5.QtWidgets import QWidget, QVBoxLayout
from PyQt5.QtChart import QChartView, QChart

class CustomWidget(QWidget):
    def __init__(self):
        super().__init__()

class CustomWidget(QWidget):
    def __init__(self):
        super().__init__()

        # 创建QChartView和QChart对象
        chart_view = QChartView()
        chart = QChart()

        # 设置布局
        layout = QVBoxLayout()
        layout.addWidget(chart_view)
        self.setLayout(layout)

class CustomWidget(QWidget):
    def __init__(self):
        super().__init__()

        # 创建QChartView和QChart对象
        chart_view = QChartView()
        chart = QChart()

        # 设置布局
        layout = QVBoxLayout()
        layout.addWidget(chart_view)
        self.setLayout(layout)

    def set_chart_data(self, data):
        # 设置图表数据和样式
        series = QLineSeries()
        for x, y in data:
            series.append(x, y)
        chart = self.chart_view.chart()
        chart.addSeries(series)
        chart.createDefaultAxes()

import sys
from PyQt5.QtWidgets import QApplication

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

    # 创建自定义小部件对象
    widget = CustomWidget()

    # 设置图表数据和样式
    data = [(1, 2), (2, 4), (3, 6), (4, 8)]
    widget.set_chart_data(data)

    widget.show()
    sys.exit(app.exec_())