PyQT4：从现有Python程序的Ui获取文本

Question

我正在为我已经做好的一个Python程序创建一个用户界面。这个界面上有两个文本框（QlineEdit），我想用它们来获取程序需要的信息，还有一个按钮和一个文本浏览器，用来显示程序的输出。

我发现了PyQT4，并通过homebrew安装了它，还有QT Creator。我已经创建了用户界面，并把它从mainwindow.ui转换成了mainwindow.py，现在我在想怎么从用户界面的文本框中获取输入的文本，并让程序使用这些文本。

我不知道怎么从文本框（QlineEdit）中提取文本，并把它们存储到程序可以使用的变量（字符串）里。

根据我的理解，我应该创建一个新的.py文件，并导入mainwindow，还有PyQT4.QtCore和PyQT4.QtGui。我不知道接下来该怎么做，所以任何建议都很有帮助。

另外，我该怎么让程序把输出显示到文本浏览器里呢？

也许我的方法有问题，我应该围绕mainwindow.py文件重新构建我的程序？

如果这些信息都很简单，我很抱歉，但我从来没有使用过PyQT或Qt Creator。

这是我从转换后的.ui文件得到的.py代码：

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

# Form implementation generated from reading ui file 'mainwindow.ui'
#
# Created: Wed Aug 13 15:25:22 2014
#      by: PyQt4 UI code generator 4.11.1
#
# WARNING! All changes made in this file will be lost!

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(480, 385)
        MainWindow.setWindowOpacity(1.0)
        self.centralWidget = QtGui.QWidget(MainWindow)
        self.centralWidget.setObjectName(_fromUtf8("centralWidget"))
        self.textBrowser = QtGui.QTextBrowser(self.centralWidget)
        self.textBrowser.setGeometry(QtCore.QRect(100, 120, 256, 192))
        self.textBrowser.setObjectName(_fromUtf8("textBrowser"))
        self.widget = QtGui.QWidget(self.centralWidget)
        self.widget.setGeometry(QtCore.QRect(150, 10, 156, 97))
        self.widget.setObjectName(_fromUtf8("widget"))
        self.verticalLayout_2 = QtGui.QVBoxLayout(self.widget)
        self.verticalLayout_2.setMargin(0)
        self.verticalLayout_2.setObjectName(_fromUtf8("verticalLayout_2"))
        self.verticalLayout = QtGui.QVBoxLayout()
        self.verticalLayout.setObjectName(_fromUtf8("verticalLayout"))
        self.lineEdit = QtGui.QLineEdit(self.widget)
        self.lineEdit.setObjectName(_fromUtf8("lineEdit"))
        self.verticalLayout.addWidget(self.lineEdit)
        self.lineEdit_2 = QtGui.QLineEdit(self.widget)
        self.lineEdit_2.setObjectName(_fromUtf8("lineEdit_2"))
        self.verticalLayout.addWidget(self.lineEdit_2)
        self.verticalLayout_2.addLayout(self.verticalLayout)
        self.pushButton = QtGui.QPushButton(self.widget)
        self.pushButton.setObjectName(_fromUtf8("pushButton"))
        self.verticalLayout_2.addWidget(self.pushButton)
        MainWindow.setCentralWidget(self.centralWidget)
        self.menuBar = QtGui.QMenuBar(MainWindow)
        self.menuBar.setGeometry(QtCore.QRect(0, 0, 480, 22))
        self.menuBar.setObjectName(_fromUtf8("menuBar"))
        MainWindow.setMenuBar(self.menuBar)
        self.mainToolBar = QtGui.QToolBar(MainWindow)
        self.mainToolBar.setObjectName(_fromUtf8("mainToolBar"))
        MainWindow.addToolBar(QtCore.Qt.TopToolBarArea, self.mainToolBar)
        self.statusBar = QtGui.QStatusBar(MainWindow)
        self.statusBar.setObjectName(_fromUtf8("statusBar"))
        MainWindow.setStatusBar(self.statusBar)

        self.retranslateUi(MainWindow)
        QtCore.QObject.connect(self.lineEdit, QtCore.SIGNAL(_fromUtf8("textEdited(QString)")), self.lineEdit.setText)
        QtCore.QObject.connect(self.lineEdit_2, QtCore.SIGNAL(_fromUtf8("textEdited(QString)")), self.lineEdit_2.setText)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow", None))
        self.lineEdit.setPlaceholderText(_translate("MainWindow", "Enter Case Number", None))
        self.lineEdit_2.setPlaceholderText(_translate("MainWindow", "Number of cases", None))
        self.pushButton.setText(_translate("MainWindow", "Submit", None))


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_())

任何信息都很有帮助。谢谢！

Answer 1

用户界面（UI）的工作方式是，UI形成程序的主循环。在这里，mainwindow.py就是你的主循环。你可以导入你在程序中创建的类（我们称之为code.py），或者直接把这些代码粘贴到mainwindow.py里。然后在按钮被按下或者其他事件发生时，你可以调用一个函数来执行code.py中的主代码。

关于你其他的问题，比如如何使用文本和打印到文本浏览器，可以试试下面的代码：

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

# Form implementation generated from reading ui file 'mainwindow.ui'
#
# Created: Wed Aug 13 15:25:22 2014
#      by: PyQt4 UI code generator 4.11.1
#
# WARNING! All changes made in this file will be lost!

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(480, 385)
        MainWindow.setWindowOpacity(1.0)
        self.centralWidget = QtGui.QWidget(MainWindow)
        self.centralWidget.setObjectName(_fromUtf8("centralWidget"))
        self.textBrowser = QtGui.QTextBrowser(self.centralWidget)
        self.textBrowser.setGeometry(QtCore.QRect(100, 120, 256, 192))
        self.textBrowser.setObjectName(_fromUtf8("textBrowser"))
        self.widget = QtGui.QWidget(self.centralWidget)
        self.widget.setGeometry(QtCore.QRect(150, 10, 156, 97))
        self.widget.setObjectName(_fromUtf8("widget"))
        self.verticalLayout_2 = QtGui.QVBoxLayout(self.widget)
        self.verticalLayout_2.setMargin(0)
        self.verticalLayout_2.setObjectName(_fromUtf8("verticalLayout_2"))
        self.verticalLayout = QtGui.QVBoxLayout()
        self.verticalLayout.setObjectName(_fromUtf8("verticalLayout"))
        self.lineEdit = QtGui.QLineEdit(self.widget)
        self.lineEdit.setObjectName(_fromUtf8("lineEdit"))
        self.verticalLayout.addWidget(self.lineEdit)
        self.lineEdit_2 = QtGui.QLineEdit(self.widget)
        self.lineEdit_2.setObjectName(_fromUtf8("lineEdit_2"))
        self.verticalLayout.addWidget(self.lineEdit_2)
        self.verticalLayout_2.addLayout(self.verticalLayout)
        self.pushButton = QtGui.QPushButton(self.widget)
        self.pushButton.setObjectName(_fromUtf8("pushButton"))
        self.verticalLayout_2.addWidget(self.pushButton)
        MainWindow.setCentralWidget(self.centralWidget)
        self.menuBar = QtGui.QMenuBar(MainWindow)
        self.menuBar.setGeometry(QtCore.QRect(0, 0, 480, 22))
        self.menuBar.setObjectName(_fromUtf8("menuBar"))
        MainWindow.setMenuBar(self.menuBar)
        self.mainToolBar = QtGui.QToolBar(MainWindow)
        self.mainToolBar.setObjectName(_fromUtf8("mainToolBar"))
        MainWindow.addToolBar(QtCore.Qt.TopToolBarArea, self.mainToolBar)
        self.statusBar = QtGui.QStatusBar(MainWindow)
        self.statusBar.setObjectName(_fromUtf8("statusBar"))
        MainWindow.setStatusBar(self.statusBar)

        self.retranslateUi(MainWindow)
        QtCore.QObject.connect(self.lineEdit, QtCore.SIGNAL(_fromUtf8("textEdited(QString)")), self.lineEdit.setText)
        QtCore.QObject.connect(self.lineEdit_2, QtCore.SIGNAL(_fromUtf8("textEdited(QString)")), self.lineEdit_2.setText)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow", None))
        self.lineEdit.setPlaceholderText(_translate("MainWindow", "Enter Case Number", None))
        self.lineEdit_2.setPlaceholderText(_translate("MainWindow", "Number of cases", None))
        self.pushButton.setText(_translate("MainWindow", "Submit", None))

        # Call a function when the button "Submit" is pressed
        self.pushButton.clicked.connect(self.OnSubmit)


    def OnSubmit(self):

        # On submit do the necessary 
        # here I take the text from the LineEdits that you have 
        # (ie your Case Number, and number of Cases) 
        # and print them to the textbrowser below

        text = self.lineEdit.text() + ' ' + self.lineEdit_2.text()
        self.textBrowser.append(text)

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_())

你可以在这里找到一些基础教程：http://zetcode.com/gui/pyqt4/，这些教程可以帮助你理解QtGui对象的属性。