解决PyQt5 无边框后窗口的移动问题

  def mousePressEvent(self, event):
    if event.button()==Qt.LeftButton:
      self.m_flag=True
      self.m_Position=event.globalPos()-self.pos() #获取鼠标相对窗口的位置
      event.accept()
      self.setCursor(QCursor(Qt.OpenHandCursor)) #更改鼠标图标
      
  def mouseMoveEvent(self, QMouseEvent):
    if Qt.LeftButton and self.m_flag: 
      self.move(QMouseEvent.globalPos()-self.m_Position)#更改窗口位置
      QMouseEvent.accept()
      
  def mouseReleaseEvent(self, QMouseEvent):
    self.m_flag=False
    self.setCursor(QCursor(Qt.ArrowCursor))

  @pyqtSlot()
  def on_pushButton_clicked(self):
    """
    关闭窗口
    """
    self.close()
  
  @pyqtSlot()
  def on_pushButton_2_clicked(self):
    """
    最小化窗口
    """
    self.showMinimized()

# 设置窗体无边框
# self.setWindowFlags(Qt.FramelessWindowHint)
# 设置背景透明
# self.setAttribute(Qt.WA_TranslucentBackground)

from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtGui import *
import sys
class Example(QWidget):
  _startPos = None
  _endPos = None
  _isTracking = False
  def __init__(self):
    super().__init__()
    self._initUI()
  def _initUI(self):
    self.setFixedSize(QSize(400, 400))
    self.setWindowFlags(Qt.FramelessWindowHint) # 无边框
    self.show()
  def mouseMoveEvent(self, e: QMouseEvent): # 重写移动事件
    self._endPos = e.pos() - self._startPos
    self.move(self.pos() + self._endPos)
  def mousePressEvent(self, e: QMouseEvent):
    if e.button() == Qt.LeftButton:
      self._isTracking = True
      self._startPos = QPoint(e.x(), e.y())
  def mouseReleaseEvent(self, e: QMouseEvent):
    if e.button() == Qt.LeftButton:
      self._isTracking = False
      self._startPos = None
      self._endPos = None
if __name__ == '__main__':
  app = QApplication(sys.argv)
  ex = Example()
  sys.exit(app.exec_())