import sys
import demo # 这里是ui文件转换的文件名
from PyQt5.QtWidgets import QApplication, QMainWindow
if __name__ == '__main__':
app = QApplication(sys.argv)
mainWindow = QMainWindow() # 获取主窗口mainWindow
ui = demo.Ui_MainWindow() # 获取demo中的组件
ui.setupUi(mainWindow) # 生成窗口
mainWindow.show() # 显示mainWindow
sys.exit(app.exec_()) # app.exec_()运行主循环，sys.exit()可以判断程序退出并返回到主线程
import sys
import demo
from PyQt5.QtWidgets import QApplication, QMainWindow
if __name__ == '__main__':
app = QApplication(sys.argv)
mainWindow = QMainWindow()
ui = demo.Ui_MainWindow()
ui.setupUi(mainWindow)
mainWindow.show()
sys.exit(app.exec_())
import sys
import demo
from PyQt5 import QtCore
from PyQt5.QtWidgets import QApplication,QMainWindow
if __name__ == '__main__':
QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)
app = QApplication(sys.argv) # 创建应用对象
mainWindow = QMainWindow() # 创建主窗口对象
ui = demo.Ui_MainWindow() # 实例化类对象
ui.setupUi(mainWindow) # 在主窗口添加控件(需传入一个参数)
mainWindow.show() # 显示窗口
sys.exit(app.exec_()) # 进入程序主循环，并通过exit函数确保主循环安全结束