python - 我有 2 个组合框（comboBox_1，comboBox_2）comboBox_1 并用正确的数据填充组合框_2
问题描述
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(711, 425)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.lineEdit_1 = QtWidgets.QLineEdit(self.centralwidget)
self.lineEdit_1.setGeometry(QtCore.QRect(110, 110, 200, 40))
font = QtGui.QFont()
font.setPointSize(18)
font.setBold(True)
font.setWeight(75)
self.lineEdit_1.setFont(font)
self.lineEdit_1.setObjectName("lineEdit_1")
self.lineEdit_2 = QtWidgets.QLineEdit(self.centralwidget)
self.lineEdit_2.setGeometry(QtCore.QRect(390, 110, 200, 40))
font = QtGui.QFont()
font.setPointSize(18)
font.setBold(True)
font.setWeight(75)
self.lineEdit_2.setFont(font)
self.lineEdit_2.setObjectName("lineEdit_2")
self.label_2 = QtWidgets.QLabel(self.centralwidget)
self.label_2.setGeometry(QtCore.QRect(340, 110, 31, 31))
font = QtGui.QFont()
font.setPointSize(28)
font.setBold(True)
font.setWeight(75)
self.label_2.setFont(font)
self.label_2.setObjectName("label_2")
self.comboBox_2 = QtWidgets.QComboBox(self.centralwidget)
self.comboBox_2.setGeometry(QtCore.QRect(110, 170, 481, 40))
font = QtGui.QFont()
font.setPointSize(18)
font.setBold(True)
font.setWeight(75)
self.comboBox_2.setFont(font)
self.comboBox_2.setObjectName("comboBox_2")
self.label_3 = QtWidgets.QLabel(self.centralwidget)
self.label_3.setGeometry(QtCore.QRect(8, 260, 101, 31))
font = QtGui.QFont()
font.setPointSize(16)
font.setBold(True)
font.setWeight(75)
self.label_3.setFont(font)
self.label_3.setObjectName("label_3")
self.quitBtn = QtWidgets.QPushButton(self.centralwidget)
self.quitBtn.setGeometry(QtCore.QRect(547, 320, 121, 51))
font = QtGui.QFont()
font.setPointSize(16)
font.setBold(True)
font.setWeight(75)
self.quitBtn.setFont(font)
self.quitBtn.setObjectName("quitBtn")
self.clearBtn = QtWidgets.QPushButton(self.centralwidget)
self.clearBtn.setGeometry(QtCore.QRect(400, 320, 121, 51))
font = QtGui.QFont()
font.setPointSize(16)
font.setBold(True)
font.setWeight(75)
self.clearBtn.setFont(font)
self.clearBtn.setObjectName("clearBtn")
self.formula_lbl = QtWidgets.QLabel(self.centralwidget)
self.formula_lbl.setGeometry(QtCore.QRect(107, 260, 561, 31))
font = QtGui.QFont()
font.setPointSize(14)
font.setBold(True)
font.setWeight(75)
self.formula_lbl.setFont(font)
self.formula_lbl.setText("\tFahrenheit = 9/5 * Celcius + 32")
self.formula_lbl.setObjectName("formula_lbl")
self.comboBox_1 = QtWidgets.QComboBox(self.centralwidget)
self.comboBox_1.setGeometry(QtCore.QRect(110, 50, 481, 40))
font = QtGui.QFont()
font.setPointSize(18)
font.setBold(True)
font.setWeight(75)
self.comboBox_1.setFont(font)
self.comboBox_1.setLayoutDirection(QtCore.Qt.LeftToRight)
self.comboBox_1.setObjectName("comboBox_1")
self.label_1 = QtWidgets.QLabel(self.centralwidget)
self.label_1.setGeometry(QtCore.QRect(250, 0, 211, 32))
font = QtGui.QFont()
font.setPointSize(18)
font.setBold(True)
font.setWeight(75)
self.label_1.setFont(font)
self.label_1.setLayoutDirection(QtCore.Qt.LeftToRight)
self.label_1.setTextFormat(QtCore.Qt.RichText)
self.label_1.setObjectName("label_1")
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 711, 30))
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)
# When quitBtn is clicked quit app
self.quitBtn.clicked.connect(QtWidgets.qApp.quit)
""" When clearBtn is clicked lineEdit_1 and lineEdit_2 are cleared """
self.clearBtn.clicked.connect(self.lineEdit_1.clear)
self.clearBtn.clicked.connect(self.lineEdit_2.clear)
# Add items to combobox_1
# self.comboBox_1.addItem("Temperature Conversion") # comboBox_1 Index 0
# self.comboBox_1.addItem("Speed Conversion") # comboBox_1 Index 1
self.comboBox_1.addItems(("Temperature", "Speed"))
# Add items temperature Items to combobox_2
self.comboBox_2.addItem("Celsius to Fahrenheight") # comboBox_2 Index 0
self.comboBox_2.addItem("Fahrenheight to Celsius") # comboBox_2 Index 1
self.comboBox_2.addItem("Kelvin to Fahrenheight") # comboBox_2 Index 2
self.comboBox_2.addItem("Fahrenheight to Kelvin") # comboBox_2 Index 3
self.comboBox_2.addItem("Celsius to Kelvin") # comboBox_2 Index 4
self.comboBox_2.addItem("Kelvin to Celsius") # comboBox_2 Index 5
# Add Speed Items to comboBox_2
self.comboBox_2.addItem("Miles per hour to Kilometer") # comboBox_2 Index 6
self.comboBox_2.addItem("Kilometer to Miles per hour") # comboBox_2 Index 7
#---------------------------------------------------------------------
""" Checks if the current comboBox_1 selection has changed """
self.comboBox_1.currentIndexChanged.connect(self.combobox1_changed,
self.comboBox_1.currentIndex())
self.comboBox_1.setCurrentIndex(0)
""" Checks if the current comboBox_2 selection has changed """
self.comboBox_2.currentIndexChanged.connect(self.combobox2_changed,
self.comboBox_2.currentIndex())
self.comboBox_2.setCurrentIndex(0)
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "Conversion App"))
self.label_2.setText(_translate("MainWindow", "="))
self.label_3.setText(_translate("MainWindow", "<html><head/><body><p><span style=\" color:#ff5500;\">Formula:</span></p></body></html>"))
self.quitBtn.setText(_translate("MainWindow", "Quit"))
self.clearBtn.setText(_translate("MainWindow", "Clear"))
self.label_1.setText(_translate("MainWindow", " "))
# This is for my reference from my CLI app
""" function to convert celcius to fahrenheit """
""" Celsius = Index 1 """
# def convert_to_fahrenheit():
# celcius_formula = "fahrenheit = 9/5 * celcius + 32"
# self.formula_lbl.additem(celcius_formula)
# try:
# celcius = float(self.lineEdit_1)
# fahrenheit = 9/5 * celcius + 32
# except ValueError:
# print("Please enter numbers only.\n")
# return convert_to_fahrenheit()
# else:
# return self.lineEdit_2.addItem(str(round(fahrenheit, 1)))
# convert_to_fahrenheit()
我想在 comboBox_1 中选择一个项目并使用正确的数据填充 comboBox_2 以供我选择
解决方案
首先，您似乎是在 Qt Designer 中设计您的 GUI，然后直接编辑导出的 .py 文件。这几乎总是一个坏主意，因为如果您以后决定在 Qt Designer 中更新您的 GUI，当您重新导出 GUI 时，对 .py 文件的任何更改都将丢失。更好的方法是保持导出的 .py 文件完整，然后将其导入另一个 python 文件，您可以使用它来设置 .py 的实例QMainWindow。一种常见的方法是创建一个单独的类，该类继承自基本小部件（QMainWindow在本例中）和 UI 类（'Ui_MainWindow'），并在其中设置所需的信号和插槽。
至于回答实际问题：为了在组合框 1 中选择项目时动态更改组合框 2 中的项目，您可以使用字典，将组合框 1 中的每个项目映射到组合框 2 中相应的项目列表。您然后可以使用第二个字典来存储每个可能的公式。这有一个额外的好处，即您不需要一长串 if-elif 语句来计算结果。
举个例子，假设Ui_MainWindow.py是从 Qt Designer 导出的 python 文件，那么主文件可能类似于
from PyQt5 import QtWidgets, QtCore
from Ui_MainWindow import Ui_MainWindow
class MyMainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self):
super().__init__()
# use Ui_MainWindow.setupUi to setup ui
self.setupUi(self)
# connect quitBtn.clicked and clearBtn.clicked as before
self.quitBtn.clicked.connect(QtWidgets.qApp.quit)
self.clearBtn.clicked.connect(self.lineEdit_1.clear)
self.clearBtn.clicked.connect(self.lineEdit_2.clear)
# add items to combobox 1
self.comboBox_1.addItems(("Temperature", "Speed"))
# dict for storing items in combobox 2 corresponding to items in combobox 1
self.combobox2_dict = {
'Temperature': ["Celsius to Fahrenheit", "Fahrenheight to Celsius",
"Kelvin to Fahrenheit", "Fahrenheit to Kelvin",
"Celsius to Kelvin", "Kelvin to Celsius"],
'Speed': ["Miles per hour to Kilometer per hour", "Kilometer per hour to Miles per hour"]}
self.transformation_dict = {
"Celsius to Fahrenheit": (lambda T: 9 / 5 * T + 32, 'fahrenheit = 9/5 * celsius + 32'),
"Fahrenheight to Celsius": (lambda T: (T - 32) * 5 / 9, 'celsius = 5/9 * (fahrenheit - 32)'),
"Kelvin to Fahrenheit": (lambda T: 9 / 5 * (T - 273.15) + 32, 'fahrenheit = ... kelvin'),
"Fahrenheit to Kelvin": (lambda T: (T - 32) * 5 / 9 + 273.15, 'kelvin = ... fahrenheit'),
"Celsius to Kelvin": (lambda T: T + 273.15, 'kelvin = celsius + 273.15'),
"Kelvin to Celsius": (lambda T: T - 273.15, 'celsius = kelvin - 273.15'),
"Miles per hour to Kilometer per hour": (lambda v: v*1.60934, 'miles/h = 1.60934 * km/h'),
"Kilometer per hour to Miles per hour": (lambda v: v/1.60934, 'km/h = 0.62137 * miles/h') }
# connect signals to slots for updating combobox 2, the formula label and calculating the result.
self.comboBox_1.currentTextChanged.connect(self.combobox1_changed)
# reset label and recalculate result when comboBox_2 changes
self.comboBox_2.currentTextChanged.connect(self.calculate_result)
self.comboBox_2.currentTextChanged.connect(self.set_formula_label)
# recalculate result when lineEdit_1 changes
self.lineEdit_1.textChanged.connect(self.calculate_result)
# initialize formula label
self.comboBox_1.currentTextChanged.emit(self.comboBox_1.currentText())
def combobox1_changed(self, text):
blocked = self.comboBox_2.blockSignals(True)
self.comboBox_2.clear()
self.comboBox_2.addItems(self.combobox2_dict.get(text, []))
self.comboBox_2.blockSignals(blocked)
self.comboBox_2.setCurrentIndex(0)
self.comboBox_2.currentTextChanged.emit(self.comboBox_2.currentText())
def set_formula_label(self, text):
formula = self.transformation_dict[text][1]
self.formula_lbl.setText(formula)
def calculate_result(self):
# Attempt to calculate result by reading text from self.lineEdit_1 and extracting the
# transformation function from self.transformation_dict
try:
# retrieve transformation function and formula as string from dictionary
func = self.transformation_dict[self.comboBox_2.currentText()][0]
val0 = float(self.lineEdit_1.text())
val1 = func(val0)
self.lineEdit_2.setText(f'{val1:0.2f}')
except:
self.lineEdit_2.setText('')
if __name__ == "__main__":
app = QtWidgets.QApplication([])
win = MyMainWindow()
win.show()
app.exec()
推荐阅读
- python - 根据用户输入从 csv 文件中选择列
- r - 在R中动态读取excel数据
- c# - 如何在 C#、Visual Studio 中更新 Telerik 主题版本
- powershell - 作为邮件附件添加的 Powershell base64 内容会破坏文本格式
- regex - 如何获取多行文本中两个字符串之间的中间字符串？
- python-3.x - RZpipe 抛出 OSError
- kotlin - 如何在 Kotlin 中表达“在第一次调用时只赋值一次”？
- flutter - 何时在 Flutter 中使用 FutureBuilder
- python-3.x - 通过python正则表达式删除包含特殊字符的字符串
- postgresql - go postgres 重构 pq CopyIn 到 pgx CopyFrom