button = QPushButton('开始称重', login_widget) button.move(100, 100) button.setGeometry(300, 200, 200, 50) button.clicked.connect()点击后怎么调用新的.py文件中class MainWindow(QMainWindow): def init(self, user_id): super().init() self.user_id = user_id self.initUI() # 打开串口 self.ser = serial.Serial('COM7', 9600, timeout=1) def initUI(self): # 创建用于显示员工信息的控件 self.info_label = QLabel("员工信息", self) self.info_label.move(100, 50) self.info_label.setStyleSheet("font-size: 24px; color: black; background-color: #eee; border-radius: 10px;") self.id_label = QLabel("员工ID：", self) self.id_label.move(70, 100) self.id_label.setStyleSheet("font-size: 18px; color: black;") self.name_label = QLabel("姓名：", self) self.name_label.move(70, 150) self.name_label.setStyleSheet("font-size: 18px; color: black;") self.six_label = QLabel("性别：", self) self.six_label.move(70, 200) self.six_label.setStyleSheet("font-size: 18px; color: black;") self.sfz_label = QLabel("身份证：", self) self.sfz_label.move(70, 250) self.sfz_label.setStyleSheet("font-size: 18px; color: black;") self.tel_label = QLabel("电话：", self) self.tel_label.move(70, 300) self.tel_label.setStyleSheet("font-size: 18px; color: black;") self.setFixedSize(800, 500) self.setWindowTitle('员工信息') # 查询员工信息 def query_employee(self, id): conn = pymysql.connect(host='39.99.214.172', user='root', password='Solotion.123', database='jj_tset') cursor = conn.cursor() cursor.execute("SELECT * FROM employee_table WHERE user_id='%s'" % id) result = cursor.fetchone() conn.close() return result # 读取数据 def read_data(self): data = self.ser.readline() if data: # 解析数据 id = data.decode().strip() # 查询员工信息 result = self.query_employee(id) if result: # 更新UI界面 self.id_label.setText("员工ID：" + result[0]) self.name_label.setText("姓名：" + str(result[1])) self.six_label.setText("性别：" + result[2]) self.sfz_label.setText("身份证：" + str(result[3])) self.tel_label.setText("电话：" + result[4]) print(result[0],result[1],result[2],result[3],result[4]) else: # 显示空白信息 self.id_label.setText("员工ID：") self.name_label.setText("姓名：") self.six_label.setText("性别：") self.sfz_label.setText("身份证：") self.tel_label.setText("电话：") # 定时读取数据 QTimer.singleShot(100, self.read_data) def closeEvent(self, event): # 关闭串口 self.ser.close()

首先需要导入需要调用的类，然后在按钮的clicked.connect()中连接到一个函数，该函数中创建一个MainWindow的实例并传入user_id参数，最后调用show()方法显示窗口。代码如下：

from PyQt5.QtWidgets import QApplication, QMainWindow
from mainWindow import MainWindow

def open_main_window():
    user_id = "123"  # 这里需要根据具体情况传入员工的ID
    main_window = MainWindow(user_id)
    main_window.show()

button = QPushButton('开始称重', login_widget)
button.move(100, 100)
button.setGeometry(300, 200, 200, 50)
button.clicked.connect(open_main_window)