Widget.py

from PyQt5.QtCore import Qt
from PyQt5.QtWidgets import QWidget


class RoundedWindow(QWidget):
    def __init__(self):
        super(QWidget, self).__init__()
        self.setWindowFlag(Qt.WindowStaysOnTopHint, True)
        self.setWindowFlags(self.windowFlags() | Qt.FramelessWindowHint)
        self.setAttribute(Qt.WA_TranslucentBackground, True)

    def mousePressEvent(self, event):
        """鼠标点击事件"""
        if event.button() == Qt.LeftButton:
            self.mPos = event.pos()
        event.accept()

    def mouseReleaseEvent(self, event):
        """鼠标弹起事件"""
        self.mPos = None
        event.accept()

    def mouseMoveEvent(self, event):
        if event.buttons() == Qt.LeftButton and self.mPos:
            self.move(self.mapToGlobal(event.pos() - self.mPos))
        event.accept()

    def window_top(self, flag: bool):
        # 没有这行代码会使窗口的标题栏消失
        if flag:
            self.windowHandle().setFlags(self.windowFlags() | Qt.WindowType.WindowStaysOnTopHint)

        else:
            self.windowHandle().setFlags(self.windowFlags() & ~Qt.WindowStaysOnTopHint)

        self.repaint()