Python_PyQt5入门系列1：LineEdit的读取与写入（后台计算）

通过实现任意两个经纬度计算两点之间的距离为例子

程序生成截图：

#以下是GUI图形界面的创建

from PyQt5import QtCore, QtGui, QtWidgets

from mathimport *

class Ui_MainWindow(object):

def setupUi(self, MainWindow):

MainWindow.setObjectName("MainWindow")

MainWindow.resize(800, 599)

self.centralwidget = QtWidgets.QWidget(MainWindow)

self.centralwidget.setObjectName("centralwidget")

self.label_2 = QtWidgets.QLabel(self.centralwidget)

self.label_2.setGeometry(QtCore.QRect(70, 90, 41, 16))

self.label_2.setObjectName("label_2")

self.label_5 = QtWidgets.QLabel(self.centralwidget)

self.label_5.setGeometry(QtCore.QRect(70, 150, 41, 9))

self.label_5.setObjectName("label_5")

self.label_6 = QtWidgets.QLabel(self.centralwidget)

self.label_6.setGeometry(QtCore.QRect(50, 230, 41, 9))

self.label_6.setObjectName("label_6")

self.label_3 = QtWidgets.QLabel(self.centralwidget)

self.label_3.setGeometry(QtCore.QRect(270, 90, 41, 16))

self.label_3.setObjectName("label_3")

self.label_7 = QtWidgets.QLabel(self.centralwidget)

self.label_7.setGeometry(QtCore.QRect(270, 150, 41, 9))

self.label_7.setObjectName("label_7")

self.lineEdit = QtWidgets.QLineEdit(self.centralwidget)

self.lineEdit.setGeometry(QtCore.QRect(50, 110, 71, 31))

self.lineEdit.setObjectName("lineEdit")

self.lineEdit_2 = QtWidgets.QLineEdit(self.centralwidget)

self.lineEdit_2.setGeometry(QtCore.QRect(50, 170, 71, 31))

self.lineEdit_2.setObjectName("lineEdit_2")

self.lineEdit_3 = QtWidgets.QLineEdit(self.centralwidget)

self.lineEdit_3.setGeometry(QtCore.QRect(250, 110, 71, 31))

self.lineEdit_3.setObjectName("lineEdit_3")

self.lineEdit_4 = QtWidgets.QLineEdit(self.centralwidget)

self.lineEdit_4.setGeometry(QtCore.QRect(250, 170, 71, 31))

self.lineEdit_4.setObjectName("lineEdit_4")

self.lineEdit_5 = QtWidgets.QLineEdit(self.centralwidget)

self.lineEdit_5.setGeometry(QtCore.QRect(80, 220, 71, 31))

self.lineEdit_5.setObjectName("lineEdit_5")

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

self.pushButton.setGeometry(QtCore.QRect(170, 300, 56, 17))

self.pushButton.setObjectName("pushButton")

MainWindow.setCentralWidget(self.centralwidget)

self.menubar = QtWidgets.QMenuBar(MainWindow)

self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 18))

self.menubar.setObjectName("menubar")

MainWindow.setMenuBar(self.menubar)

self.statusbar = QtWidgets.QStatusBar(MainWindow)

self.statusbar.setObjectName("statusbar")

MainWindow.setStatusBar(self.statusbar)

self.retranslateUi(MainWindow)

self.pushButton.clicked.connect(self.btnshanbing_click)

QtCore.QMetaObject.connectSlotsByName(MainWindow)

def retranslateUi(self, MainWindow):

_translate = QtCore.QCoreApplication.translate

MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))

self.label_2.setText(_translate("MainWindow", "经度"))

self.label_5.setText(_translate("MainWindow", "经度"))

self.label_6.setText(_translate("MainWindow", "距离"))

self.label_3.setText(_translate("MainWindow", "经度"))

self.label_7.setText(_translate("MainWindow", "经度"))

self.pushButton.setText(_translate("MainWindow", "确定"))

#以下是btnshanbing_click信号的槽函数

def btnshanbing_click(self):

#以下是将文本框里面的内容读取出来同时将里面的类型转换为浮点型

a=float(self.lineEdit.text())

c=float(self.lineEdit_2.text())

b=float(self.lineEdit_3.text())

d=float(self.lineEdit_4.text())

#以下是经纬度计算公式

e=(acos(sin(b * pi /180) * sin(d * pi /180) + cos(c * pi /180 - a * pi /180) * cos(b * pi /180) * cos(d * pi /180)))*6371004

#以下是将计算的结果生成在LineEdit_5里面去，但是要注意的是必须将计算的结果转换为字符型，否则程序运行不起来

       self.lineEdit_5.setText(str(e))

主程序：

self.lineEdit.text()：读取文本框里面的内容，但是要做计算必须转换为float(self.lineEdit.text())浮点型才能做运算，否则不能运算

self.lineEdit_5.setText(str())：将计算的结果生成在另一个文本框里面必须转换为字符型，否则程序会报错。

综上所述：lineEdit.text()的返回类型为文本型

'''

【简介】

PyQT5中 QTimer例子

'''

import sys

from PyQt5.QtCore import *

from PyQt5.QtGui import *

from PyQt5.QtWidgets import *

global sec

sec = 0

class WorkThread(QThread):

trigger = pyqtSignal()

def countTime():

global sec

sec += 1

# LED显示数字+1

lcdNumber.display(sec)

def work():

# 计时器每秒计数

timer.start(1000)

# 计时开始

workThread.start()

# 当获得循环完毕的信号时，停止计数

workThread.trigger.connect(timeStop)

def timeStop():

timer.stop()

print("运行结束用时", lcdNumber.value())

global sec

sec = 0

if name == " main ":

app = QApplication(sys.argv)

top = QWidget()

top.resize(300, 120)

'''

【简介】

PyQT5中 QThread 例子

'''

from PyQt5.QtCore import *

from PyQt5.QtGui import *

from PyQt5.QtWidgets import *

import sys

class MainWidget(QWidget):

def init (self, parent=None):

super(MainWidget, self). init (parent)

self.setWindowTitle("QThread 例子")

self.thread = Worker()

self.listFile = QListWidget()

self.btnStart = QPushButton('开始')

layout = QGridLayout(self)

layout.addWidget(self.listFile, 0, 0, 1, 2)

layout.addWidget(self.btnStart, 1, 1)

self.btnStart.clicked.connect(self.slotStart)

self.thread.sinOut.connect(self.slotAdd)

class Worker(QThread):

sinOut = pyqtSignal(str)

if name == " main ":

app = QApplication(sys.argv)

demo = MainWidget()

demo.show()

sys.exit(app.exec_())

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