PyQt5入门（一）--------信号与槽

一、说明

控件对象发出信号，与之相连接的槽函数将会自动执行。
用connect()函数可以将信号绑定到槽函数上。
使用disconnect()函数解除信号和槽之间的绑定。

二、信号与槽绑定

2.1 单对单关联

以按钮点击举例，按钮点击一次，按钮的文案在“开启”“关闭”之间切换

1、创建一个按钮，命名为Button1，按钮文案“开启”
2、生成testUI.py

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'testUI.ui'
#
# Created by: PyQt5 UI code generator 5.15.4
#
# WARNING: Any manual changes made to this file will be lost when pyuic5 is
# run again.  Do not edit this file unless you know what you are doing.


from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(717, 636)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.Button1 = QtWidgets.QPushButton(self.centralwidget)
        self.Button1.setGeometry(QtCore.QRect(290, 262, 91, 41))
        self.Button1.setObjectName("Button1")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 717, 22))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.Button1.setText(_translate("MainWindow", "开启"))

3、运行demo的脚本，run_demo.py

import sys
import testUI
from PyQt5.QtWidgets import QApplication, QMainWindow, QWidget
from testUI import Ui_MainWindow

class Window(QMainWindow,Ui_MainWindow):
    def __init__(self,parent=None):
        super(Window, self).__init__(parent)
        self.setupUi(self)
        self.init_button()

    def init_button(self):
        self.Button1.clicked.connect(self.change_button_text)

    def change_button_text(self):
        if self.Button1.text()=='开启':
            self.Button1.setText('关闭')
        else:
            self.Button1.setText('开启')

if __name__ == '__main__':
    # 实例化，传参
    app = QApplication(sys.argv)
    # 创建对象
    mainWindow = Window()
    # 创建窗口
    mainWindow.show()
    # 进入程序的主循环，并通过exit函数确保主循环安全结束(该释放资源的一定要释放)
    sys.exit(app.exec_())

4、代码解释
上述代码中创建了按钮对象self.Button1

        self.Button1 = QtWidgets.QPushButton(self.centralwidget)
        self.Button1