如何将函数绑定到 QTabWidget PyQt5 选项卡？

void QTabWidget:: currentChanged (int index )

每当当前页面的索引发生变化时，都会发出此信号。参数为当前页面的新索引位置，或-1。

注意：currentIndex 属性的通知信号。

主文件

import sys
from PyQt5.QtCore import pyqtSlot
from PyQt5.QtWidgets import QApplication, QMainWindow
from PyQt5.uic import loadUi


class New(QMainWindow):
    def __init__(self):
        super(New, self).__init__()
        
        loadUi("tabs1_2.ui", self)
        
        self.tabWidget.currentChanged.connect(self.tabChanged)
        self.tabWidget.setCurrentIndex(0)                       # +
        self.tabChanged(0)                                      # +++

    @pyqtSlot(int)                                              # +++ int
    def tabChanged(self, index):                                # +++ index
        print('Позиция индекса текущей вкладки:', self.tabWidget.currentIndex())
        print('Указатель на страницу:', self.tabWidget.currentWidget())
        
        if index == 0:                                          # +++
            self.fun1()                                         # ...
        elif index == 1:
            self.fun2()

    def fun1(self):
        print('Сработала функция 1')

    def fun2(self):
        print('Сработала функция 2')

if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = New()
#    window.showFullScreen()
    window.show()
    sys.exit(app.exec_())

tabs1_2.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>800</width>
    <height>600</height>
   </rect>
  </property>
  <property name="sizePolicy">
   <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
    <horstretch>0</horstretch>
    <verstretch>0</verstretch>
   </sizepolicy>
  </property>
  <property name="maximumSize">
   <size>
    <width>800</width>
    <height>600</height>
   </size>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <property name="styleSheet">
   <string notr="true"/>
  </property>
  <widget class="QWidget" name="centralwidget">
   <property name="minimumSize">
    <size>
     <width>800</width>
     <height>600</height>
    </size>
   </property>
   <property name="maximumSize">
    <size>
     <width>800</width>
     <height>600</height>
    </size>
   </property>
   <widget class="QGroupBox" name="groupBox">
    <property name="geometry">
     <rect>
      <x>30</x>
      <y>10</y>
      <width>730</width>
      <height>570</height>
     </rect>
    </property>
    <property name="title">
     <string>GroupBox</string>
    </property>
    <layout class="QGridLayout" name="gridLayout">
     <item row="0" column="0">
      <widget class="QTabWidget" name="tabWidget">
       <property name="maximumSize">
        <size>
         <width>800</width>
         <height>600</height>
        </size>
       </property>
       <property name="styleSheet">
        <string notr="true">background-color: rgb(255, 255, 255);</string>
       </property>
       <property name="currentIndex">
        <number>0</number>
       </property>
       <widget class="QWidget" name="tab">
        <property name="minimumSize">
         <size>
          <width>700</width>
          <height>500</height>
         </size>
        </property>
        <property name="maximumSize">
         <size>
          <width>700</width>
          <height>500</height>
         </size>
        </property>
        <attribute name="title">
         <string>Tab 1</string>
        </attribute>
       </widget>
       <widget class="QWidget" name="tab_2">
        <property name="maximumSize">
         <size>
          <width>700</width>
          <height>500</height>
         </size>
        </property>
        <attribute name="title">
         <string>Tab 2</string>
        </attribute>
        <widget class="QWidget" name="widget_2" native="true">
         <property name="geometry">
          <rect>
           <x>11</x>
           <y>11</y>
           <width>104</width>
           <height>16</height>
          </rect>
         </property>
        </widget>
       </widget>
      </widget>
     </item>
    </layout>
   </widget>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

from PySide2.QtWidgets import *
import sys

class Window(QWidget):
    def __init__(self):
        QWidget.__init__(self)
        layout = QGridLayout()
        self.setLayout(layout)
        label1 = QLabel("Индекс вкладки 0.")
        label2 = QLabel("Индекс вкладки 1.")
        tabwidget = QTabWidget()
        tabwidget.blockSignals(True)
        tabwidget.currentChanged.connect(self.onChange)
        tabwidget.addTab(label1, "Tab 0")
        tabwidget.addTab(label2, "Tab 1")
        layout.addWidget(tabwidget, 0, 0)
        tabwidget.blockSignals(False)

    def onChange(self,i):
        print(f"Индекс вкладки {i}")
        if i == 0:
            print("То что должно быть в функции 1")
        else:
            print("То что должно быть в функции 2")

app = QApplication(sys.argv)
screen = Window()
screen.show()
app.exec_()