用pyqt5写一个简单的计算器

需要先在电脑上安装Python3、pycharm、designer这三个软件，具体安装这里就不写了，下面直接进入话题。

打开DESIGNER，新建一个Main Window窗体

从左边栏里把钮和文本框控件拉出来，并修改第个控件的对象名和显示名称，如下

文本框一定要设置成只读

增加槽函数，函数名称要与后面程序中类的方法名称一样，一个按钮对应一个函数

 信号/槽编辑，这个是把按钮的动作与函数名关联起来

UI设计完成之后保存成Mainwindow.ui文件，放在目录D:file计算器

designer设计好的UI文件转成PYTHON的py文件，在cmd命令行中切换到UI文件目录，然后执行命令pyuic5.exe -o XX.py  xx.ui，下面执行pyuic5.exe -o Mainwindow.py Mainwindow.ui

 执行完后会生成一个Mainwindow.py文件

接下来开pycharm，进入到计算器目录下面新建一个Mainwindow3.py文件

 Mainwindow3.py文件代码如下

# coding: utf-8
import sys

from PyQt5 import QtWidgets,QtGui,QtWidgets

from MainWindow import Ui_MainWindow
from PyQt5 import QtCore, QtGui, QtWidgets


class CMainWindow(QtWidgets.QMainWindow,Ui_MainWindow):
    number1 = 0
    number2 = 0
    type = 0
    s = ""

    def __init__(self, parent=None):
        super(CMainWindow, self).__init__(parent)
        self.setupUi(self)
        # 主窗体设置
        self.setFixedSize(self.width(), self.height())
        self.show()

    def AddNumber(self, number):
        # print(self.s)
        self.txtDisplay.setText(self.s)

    # def Push00(self):
    #     self.s=self.s+"00"
    #     self.AddNumber("00")

    def Push0(self):
        self.s = self.s + "0"
        self.AddNumber("0")

    def Push1(self):
        self.s = self.s + "1"
        self.AddNumber("1")

    def Push2(self):
        self.s = self.s + "2"
        self.AddNumber("2")

    def Push3(self):
        self.s = self.s + "3"
        self.AddNumber("3")

    def Push4(self):
        self.s = self.s + "4"
        self.AddNumber("4")

    def Push5(self):
        self.s = self.s + "5"
        self.AddNumber("5")

    def Push6(self):
        self.s = self.s + "6"
        self.AddNumber("6")

    def Push7(self):
        self.s = self.s + "7"
        self.AddNumber("7")

    def Push8(self):
        self.s = self.s + "8"
        self.AddNumber("8")

    def Push9(self):
        self.s = self.s + "9"
        self.AddNumber("9")

    def PushDot(self):
        self.s = self.s + "."
        self.AddNumber(".")

    def PushClr(self):
        self.s = ""
        self.txtDisplay.setText("0")
        self.number1 = 0
        self.number2 = 0
        self.type = 0

    def PushAdd(self):
        self.number1 = float(self.txtDisplay.text())
        self.type = 1
        self.s = self.s + "+"
        self.AddNumber("+")

    def PushSub(self):
        self.number1 = float(self.txtDisplay.text())
        self.type = 3
        self.s = self.s + "-"
        self.AddNumber("-")

    def PushMul(self):
        self.type = 2
        self.s = self.s + "*"
        self.AddNumber("*")

    def PushDiv(self):
        self.type = 2
        self.s = self.s + "/"
        self.AddNumber("/")

    def PushEqr(self):  # 重写计算函数
        result = 0
        if (self.s.__contains__("+")):
            s = self.s.split("+")
            for i in s:
                result = result + int(i)
            print(result)
            self.s = str(result)
            self.txtDisplay.setText(self.s)

        elif (self.s[1::].__contains__("-")):
            if (self.s[0].__eq__("-")):
                self.s = self.s[1::]
                s = self.s.split("-")
                result = int(s[0] * (-1))
            else:
                s = self.s.split("-")
                result = int(s[0])
            for i in s[1::]:
                result = result - int(i)
                print(result)
                self.s = str(result)
                self.txtDisplay.setText(self.s)
        elif (self.s.__contains__("*")):
            s = self.s.split("*")
            result = int(s[0])
            for i in s[1::]:
                result = result * int(i)
            print(result)
            self.s = str(result)
            self.txtDisplay.setText(self.s)
        elif (self.s.__contains__("/")):  # 仅整除，且不能除以0
            s = self.s.split("/")
            result = int(s[0])
            for i in s[1::]:
                result = result / int(i)
            print(result)
            self.s = str(result)
            self.txtDisplay.setText(self.s)


if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = CMainWindow()
    # ui=Ui_MainWindow()
    # ui.CMainWindow(MainWindow)
    # MainWindow.show()
    sys.exit(app.exec_())

最后在pycharm中执行测试