（Python）PyQtGui单击按钮时不更新GUI

Question

我有两个单选按钮selectDate和selectTime。下面是一些小部件。我试图使这些小部件不灰显时，他们上面的单选按钮被选中。在

Python3.4（Python发行版），Windows 10 Pro 64位，Qt4 64位

下面是检查是否选中的代码：

if self.selectTime.isChecked() == True:
        self.greyOut2(MainWindow)

if self.selectDate.isChecked() == True:
        self.greyOut1(MainWindow)

这是greyOut1和{}。当执行时，它们成功地将小部件变灰。在

^{pr2}$

现在我的问题是IF语句只执行一次，所以当你选择按钮时，什么都不会发生。在

程序看起来像这样。在

这是完整的（生锈的）代码（打印是为了调试）。这是我的第一个GUI程序，我正在学习Qt一周，所以请不要使用高级代码。在

from PyQt4 import QtCore, QtGui

try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

class Ui_MainWindow(object):

    def setupUi(self, MainWindow):
        MainWindow.setObjectName(_fromUtf8("MainWindow"))
        MainWindow.resize(261, 371)
        MainWindow.setMinimumSize(QtCore.QSize(261, 371))
        MainWindow.setMaximumSize(QtCore.QSize(261, 371))
        icon = QtGui.QIcon()
        icon.addPixmap(QtGui.QPixmap(_fromUtf8("../Dropbox/python/gui/icon.png")), QtGui.QIcon.Normal, QtGui.QIcon.Off)
        MainWindow.setWindowIcon(icon)
        MainWindow.setUnifiedTitleAndToolBarOnMac(False)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setMinimumSize(QtCore.QSize(261, 371))
        self.centralwidget.setMaximumSize(QtCore.QSize(261, 371))
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.action = QtGui.QComboBox(self.centralwidget)
        self.action.setGeometry(QtCore.QRect(104, 60, 91, 22))
        self.action.setObjectName(_fromUtf8("action"))
        self.action.addItem(_fromUtf8(""))
        self.action.addItem(_fromUtf8(""))
        self.action.addItem(_fromUtf8(""))
        self.action.addItem(_fromUtf8(""))
        self.action.addItem(_fromUtf8(""))
        self.label = QtGui.QLabel(self.centralwidget)
        self.label.setGeometry(QtCore.QRect(20, 10, 221, 21))
        self.label.setObjectName(_fromUtf8("label"))
        self.label_2 = QtGui.QLabel(self.centralwidget)
        self.label_2.setGeometry(QtCore.QRect(50, 60, 51, 21))
        font = QtGui.QFont()
        font.setPointSize(12)
        self.label_2.setFont(font)
        self.label_2.setObjectName(_fromUtf8("label_2"))
        self.groupBox = QtGui.QGroupBox(self.centralwidget)
        self.groupBox.setGeometry(QtCore.QRect(10, 100, 241, 191))
        self.groupBox.setObjectName(_fromUtf8("groupBox"))
        self.selectTime = QtGui.QRadioButton(self.groupBox)
        self.selectTime.setGeometry(QtCore.QRect(20, 30, 82, 17))
        self.selectTime.setObjectName(_fromUtf8("selectTime"))
        self.buttonGroup_2 = QtGui.QButtonGroup(MainWindow)
        self.buttonGroup_2.setObjectName(_fromUtf8("buttonGroup_2"))
        self.buttonGroup_2.addButton(self.selectTime)
        self.selectDate = QtGui.QRadioButton(self.groupBox)
        self.selectDate.setGeometry(QtCore.QRect(20, 110, 82, 17))
        self.selectDate.setObjectName(_fromUtf8("selectDate"))
        self.buttonGroup_2.addButton(self.selectDate)
        self.label_3 = QtGui.QLabel(self.groupBox)
        self.label_3.setGeometry(QtCore.QRect(116, 60, 61, 20))
        font = QtGui.QFont()
        font.setPointSize(10)
        self.label_3.setFont(font)
        self.label_3.setObjectName(_fromUtf8("label_3"))
        self.relativeTime = QtGui.QTimeEdit(self.groupBox)
        self.relativeTime.setGeometry(QtCore.QRect(40, 60, 61, 22))
        self.relativeTime.setObjectName(_fromUtf8("relativeTime"))
        self.label_4 = QtGui.QLabel(self.groupBox)
        self.label_4.setGeometry(QtCore.QRect(40, 140, 21, 21))
        font = QtGui.QFont()
        font.setPointSize(10)
        self.label_4.setFont(font)
        self.label_4.setObjectName(_fromUtf8("label_4"))
        self.dateTime = QtGui.QDateTimeEdit(self.groupBox)
        self.dateTime.setGeometry(QtCore.QRect(70, 140, 111, 22))
        self.dateTime.setObjectName(_fromUtf8("dateTime"))
        self.forceCheck = QtGui.QCheckBox(self.centralwidget)
        self.forceCheck.setGeometry(QtCore.QRect(10, 300, 81, 21))
        self.forceCheck.setObjectName(_fromUtf8("forceCheck"))
        self.startButton = QtGui.QPushButton(self.centralwidget)
        self.startButton.setGeometry(QtCore.QRect(170, 300, 71, 23))
        self.startButton.setObjectName(_fromUtf8("startButton"))
        self.label_5 = QtGui.QLabel(self.centralwidget)
        self.label_5.setGeometry(QtCore.QRect(20, 330, 211, 20))
        self.label_5.setObjectName(_fromUtf8("label_5"))

        print(self.selectTime.isChecked())
        print(self.selectDate.isChecked())

        if self.selectTime.isChecked() == True:
            self.greyOut2(MainWindow)

        if self.selectDate.isChecked() == True:
            self.greyOut1(MainWindow)

        MainWindow.setCentralWidget(self.centralwidget)

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

    def retranslateUi(self, MainWindow):
        MainWindow.setWindowTitle(_translate("MainWindow", "Auto Shutdown", None))
        self.action.setItemText(0, _translate("MainWindow", "Shut Down", None))
        self.action.setItemText(1, _translate("MainWindow", "Restart", None))
        self.action.setItemText(2, _translate("MainWindow", "Sleep", None))
        self.action.setItemText(3, _translate("MainWindow", "Log Off", None))
        self.action.setItemText(4, _translate("MainWindow", "Lock", None))
        self.label.setText(_translate("MainWindow", "Please chose an action and then a time for it.", None))
        self.label_2.setText(_translate("MainWindow", "Action:", None))
        self.groupBox.setTitle(_translate("MainWindow", "Time Schedule", None))
        self.selectTime.setText(_translate("MainWindow", "Relative Time", None))
        self.selectDate.setText(_translate("MainWindow", "Date", None))
        self.label_3.setText(_translate("MainWindow", "From now", None))
        self.label_4.setText(_translate("MainWindow", "On", None))
        self.forceCheck.setText(_translate("MainWindow", "Force Action", None))
        self.startButton.setText(_translate("MainWindow", "Start", None))
        self.label_5.setText(_translate("MainWindow", "Your computer will", None))



    def greyOut1(self, MainWindow): #selectDate on
        print("go1")
        self.label_3.setEnabled(False)
        self.relativeTime.setEnabled(False)
        self.label_4.setEnabled(True)
        self.dateTime.setEnabled(True)

    def greyOut2(self, MainWindow): #selectTime on
        print("go2")
        self.lebel_3.setEnabled(True)
        self.relativeTime.setEnabled(True)
        self.label_4.setEnabled(False)
        self.dateTime.setEnabled(False)



if __name__ == "__main__":
    import sys
    app = QtGui.QApplication(sys.argv)
    MainWindow = QtGui.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

Answer 1

当调用setupUi方法时，if/else块只执行一次。在

你需要的是信号和插槽。从PyQt4 doc：

One of the key features of Qt is its use of signals and slots to communicate between objects. Their use encourages the development of reusable components.

A signal is emitted when something of potential interest happens. A slot is a Python callable. If a signal is connected to a slot then the slot is called when the signal is emitted. If a signal isn’t connected then nothing happens. The code (or component) that emits the signal does not know or care if the signal is being used.

您可以创建自己的信号，或者使用已经实现的信号。 类QRadioButton已经有四个信号继承自QAbstractButton（所有不同的按钮都有相同的信号）。 这些信号是clicked，pressed，released和{}（参见QT Doc）。当用户单击按钮时，它们会发出。在

单选按钮是可检查的，因此我们可以使用toggled(bool checked)信号。当按钮被点击时，信号会发出一个布尔值：True是按钮被选中了，False如果它没有被选中。 下面是一个简单的例子：

self.radioButton=QtGui.QRadioButton()
self.radioButton.toggled.connect(self.on_radioButton_click)

def on_radioButton_click(check):
    if check:
        print("I'm checked !")
    else:
        print("I'm unchecked !")