python - 带有自定义槽的 PyQt 可以工作，Qt 设计器不能

Question

我正在尝试围绕我已有的一些代码构建一个 GUI。我了解在手动构建 GUI 时如何执行此操作，但在将其添加到 Qt Designer 和 pyuic 生成的 python 代码时卡住了。例如，我可能需要一个按钮，允许用户指向一个文件，我手动这样做，这是可行的:

import sys
from PyQt4 import QtGui


class Example(QtGui.QWidget):    
    def __init__(self):
        super(Example, self).__init__()

        self.initUI()

    def initUI(self):        

        btn = QtGui.QPushButton('Open File', self)
        btn.setToolTip('This is a <b>QPushButton</b> widget')
        btn.resize(btn.sizeHint())
        btn.move(50, 50)     
        btn.clicked.connect(self.loadFile)

        self.setGeometry(300, 300, 250, 150)
        self.show()

    def loadFile(self):
        fname = QtGui.QFileDialog.getOpenFileName(self, 'Open file', '/home')
        # some custom code for reading file and storing it

def main():
    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

但是，当我尝试在 Qt Designer 代码中执行相同操作时，程序在到达文件对话框之前停止。

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_Form(object):
    def setupUi(self, Form):
        Form.setObjectName(_fromUtf8("Form"))
        Form.resize(400, 300)
        self.pushButton = QtGui.QPushButton(Form)
        self.pushButton.setGeometry(QtCore.QRect(130, 100, 75, 23))
        self.pushButton.setObjectName(_fromUtf8("pushButton"))

        self.retranslateUi(Form)
        QtCore.QObject.connect(self.pushButton, QtCore.SIGNAL(_fromUtf8("clicked()")), self.loadFile)
        QtCore.QMetaObject.connectSlotsByName(Form)

    def retranslateUi(self, Form):
        Form.setWindowTitle(_translate("Form", "Form", None))
        self.pushButton.setText(_translate("Form", "Open File", None))

    def loadFile(self):
        print('loadFile1')
        fname = QtGui.QFileDialog.getOpenFileName(self, 'Open file', '/home')
        print('loadFile2')


if __name__ == "__main__":
    import sys
    app = QtGui.QApplication(sys.argv)
    Form = QtGui.QWidget()
    ui = Ui_Form()
    ui.setupUi(Form)
    Form.show()
    sys.exit(app.exec_())

这只会打印 loadFile() 中的第一条语句，但不会打开文件对话框窗口。我做错了什么？

Answer 1

根据documentation :

QString getOpenFileName (QWidget parent = None, QString caption = '', QString directory = '', QString filter = '', Options options = 0)

QString getOpenFileName (QWidget parent = None, QString caption = '', QString directory = '', QString filter = '', QString selectedFilter = '', Options options = 0)

您需要将小部件或 None 作为父级传递，在您的情况下 self 不是对象类型。

你必须改变

 QtGui.QFileDialog.getOpenFileName(self, 'Open file', '/home')

到

QtGui.QFileDialog.getOpenFileName(None, 'Open file', '/home')