关于在scrollarea中添加动态按钮的问题，如何解决？

我想在scrollarea里面添加按钮，在图层上面，按钮可以随着滑动条的位置变化

import sys
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QPixmap
from PyQt5.QtWidgets import QApplication, QWidget, QLabel, QPushButton, QScrollArea, QScrollBar, \
    QHBoxLayout, QVBoxLayout,QGridLayout


class Demo(QWidget):
    def __init__(self):
        super(Demo, self).__init__()

        self.label = QLabel(self)  # 1
        self.label.setPixmap(QPixmap('./pitures/secondconnet.jpg'))
        self.label.setScaledContents(True)

        self.scroll_area = QScrollArea(self)  # 2
        self.scroll_area.setWidget(self.label)
        self.scroll_area.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)

        self.scrollbar = QScrollBar(Qt.Horizontal, self)  # 3
        self.scrollbar.setMaximum(self.scroll_area.horizontalScrollBar().maximum())


        self.scrollbar.valueChanged.connect(self.sync_func)



        self.v_layout = QVBoxLayout()
        self.v_layout.addWidget(self.scroll_area)

        self.v_layout.addWidget(self.scrollbar)

        self.setLayout(self.v_layout)



    def sync_func(self):
        self.scroll_area.horizontalScrollBar().setValue(self.scrollbar.value())


if __name__ == '__main__':
    app = QApplication(sys.argv)
    demo = Demo()
    demo.show()
    sys.exit(app.exec_())

是加了遇到问题吗