＆quot“ qwidget：必须在qwidget之前构造Qapplication”。 ，（新表格（new_main.ui）在pyqt5（）中溅起屏幕之后不显示

Question

import sys
import time
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton, QProgressBar, QLabel, QFrame, QHBoxLayout, QVBoxLayout
from PyQt5.QtCore import Qt, QTimer
from PyQt5 import QtWidgets, uic
from PyQt6.QtWidgets import QLineEdit, QMainWindow
import new_main


class SplashScreen(QWidget):
    def __init__(self):
        super().__init__()
        self.setWindowTitle('Spash Screen Example')
        self.setFixedSize(1100, 500)
        self.setWindowFlag(Qt.FramelessWindowHint)
        self.setAttribute(Qt.WA_TranslucentBackground)

        self.counter = 0
        self.n = 300  # total instance
        self.initUI()

        self.timer = QTimer()
        self.timer.timeout.connect(self.loading)
        self.timer.start(15)


    def initUI(self):
        layout = QVBoxLayout()
        self.setLayout(layout)

        self.frame = QFrame()
        layout.addWidget(self.frame)

        self.labelTitle = QLabel(self.frame)
        self.labelTitle.setObjectName('LabelTitle')

        # center labels
        self.labelTitle.resize(self.width() - 10, 150)
        self.labelTitle.move(0, 40)  # x, y
        #self.labelTitle.setText(' 3PP Sheet Automation')
        self.labelTitle.setAlignment(Qt.AlignCenter)

        self.labelDescription = QLabel(self.frame)
        self.labelDescription.resize(self.width() - 10, 50)
        self.labelDescription.move(0, self.labelTitle.height())
        self.labelDescription.setObjectName('LabelDesc')
        self.labelDescription.setText('<strong>Loading.</strong>')
        self.labelDescription.setAlignment(Qt.AlignCenter)

        self.progressBar = QProgressBar(self.frame)
        self.progressBar.resize(self.width() - 200 - 10, 50)
        self.progressBar.move(100, self.labelDescription.y() + 130)
        self.progressBar.setAlignment(Qt.AlignCenter)
        self.progressBar.setFormat('%p%')
        self.progressBar.setTextVisible(True)
        self.progressBar.setRange(0, self.n)
        self.progressBar.setValue(20)

        self.labelLoading = QLabel(self.frame)
        self.labelLoading.resize(self.width() - 10, 50)
        self.labelLoading.move(0, self.progressBar.y() + 70)
        self.labelLoading.setObjectName('LabelLoading')
        self.labelLoading.setAlignment(Qt.AlignCenter)
        #self.labelLoading.setText('loading...')

    def loading(self):
        self.progressBar.setValue(self.counter)

        if self.counter == int(self.n * 0.3):
            self.labelDescription.setText('<strong>Loading...</strong>')
        elif self.counter == int(self.n * 0.6):
            self.labelDescription.setText('<strong>Loading.....</strong>')
        elif self.counter == int(self.n * 0.9):
            self.labelDescription.setText('<strong>Loading.......</strong>')
        elif self.counter == int(self.n * 0.9):
            self.labelDescription.setText('<strong>Loading........</strong>')
        elif self.counter >= self.n:
            self.timer.stop()
            self.close()
            time.sleep(1)
            mainform = Input_form()
            self.mainform.show()


        self.counter += 1



class Input_form(QMainWindow):
    def __init__(self):
        super().__init__()
        self.uic.loadUi('new_mian.ui', self)
        self.show()


if __name__ == '__main__':
    # don't auto scale when drag app to a different monitor.
    # QApplication.setAttribute(Qt.HighDpiScaleFactorRoundingPolicy.PassThrough)

    app = QApplication(sys.argv)
    app.setStyleSheet('''
        #LabelTitle {
            font-size: 60px;
            color: #93deed;
        }

        #LabelDesc {
            font-size: 30px;
            color: #c2ced1;
        }

        #LabelLoading {
            font-size: 30px;
            color: #e8e8eb;
        }

        QFrame {
            background-color: black;
            color: rgb(220, 220, 220);
        }

        QProgressBar {
            background-color: #DA7B93;
            color: rgb(200, 200, 200);
            border-style: none;
            border-radius: 10px;
            text-align: center;
            font-size: 30px;
        }

        QProgressBar::chunk {
            border-radius: 10px;
            background-color: qlineargradient(spread:pad x1:0, x2:1, y1:0.511364, y2:0.523, stop:0 #1C3334, stop:1 #376E6F);
        }
    ''')

 
    splash = SplashScreen()
    splash.show()
  

    try:
        sys.exit(app.exec_())
    except SystemExit:
        print('Closing Window...')

在成功的飞溅屏幕加载后，我试图分配通过QT Designer创建的new_mian.ui（qmainwindow）表单，并在代码中导入。

我还使用此“ pyuic5 new_main.ui -o new_main.py”命令生成了python文件，但其提示错误“ qwidget” qwidget：必须在qwidget之前构造qapplication”。我是PYQT的新手，无法理解为什么如此。请指导。提前致谢