Gianluca Gianluca - 3 months ago 17
Python Question

I try to use QFileDialog for choose a file on PyQt but it don't run

I'm new on stackoverflow.
I have a MainWindow on PyQt, I want click a button and open a QFileDialog for choose a file. The problem is: If I use a MainWindow, QFileDialog don't run. If I use a Dialog, QFileDialog run.

This is my code for the MainWindow.

import sys
from Import_fsa import import_fsa
from PyQt4 import QtCore, QtGui
from PyQt4.QtGui import QFileDialog
from Vannucci_Gemignani import Ui_MainWindow


class GUI_fsa(QtGui.QMainWindow):
def __init__(self):

QtGui.QMainWindow.__init__(self)
self.ui=Ui_MainWindow()
self.ui.setupUi(self)

QtCore.QObject.connect(self.ui.Button_Browse, QtCore.SIGNAL('clicked()'), self.Browse)

def Browse(self):

fname=QFileDialog.getOpenFileName()


self.lineEdit.setText(fname)
data_set=import_fsa(fname)


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


This is the code for Dialog. Here I write the code in the .py generate using pyuic4 (QTDesigner)

from PyQt4 import QtCore, QtGui
from PyQt4.QtGui import QFileDialog
from ab1 import ABIFReader
import pylab

try:
_fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
_fromUtf8 = lambda s: s

class Ui_Dialog(object):
def setupUi(self, Dialog):
Dialog.setObjectName(_fromUtf8("Dialog"))
Dialog.resize(508, 363)
self.pushButton = QtGui.QPushButton(Dialog)
self.pushButton.setGeometry(QtCore.QRect(10, 40, 75, 23))
self.pushButton.setObjectName(_fromUtf8("pushButton"))
self.lineEdit = QtGui.QLineEdit(Dialog)
self.lineEdit.setGeometry(QtCore.QRect(110, 40, 361, 20))
self.lineEdit.setObjectName(_fromUtf8("lineEdit"))

self.retranslateUi(Dialog)
QtCore.QMetaObject.connectSlotsByName(Dialog)
QtCore.QObject.connect(self.pushButton, QtCore.SIGNAL('clicked()'), self.selectFile)

def retranslateUi(self, Dialog):
Dialog.setWindowTitle(QtGui.QApplication.translate("Dialog", "Dialog", None, QtGui.QApplication.UnicodeUTF8))
self.pushButton.setText(QtGui.QApplication.translate("Dialog", "PushButton", None, QtGui.QApplication.UnicodeUTF8))


def selectFile(self):
fname=QFileDialog.getOpenFileName()
self.lineEdit.setText(fname)
reader=ABIFReader(fname)
dati=reader.getData('DATA',1)
pylab.plot(dati)







if __name__ == "__main__":
import sys
app = QtGui.QApplication(sys.argv)
Dialog = QtGui.QDialog()
ui = Ui_Dialog()
ui.setupUi(Dialog)
Dialog.show()
sys.exit(app.exec_())


This is Vannucci_Gemignani.py:

from PyQt4 import QtCore, QtGui

try:
_fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
_fromUtf8 = lambda s: s

class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName(_fromUtf8("MainWindow"))
MainWindow.resize(1445, 744)
self.centralwidget = QtGui.QWidget(MainWindow)
self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
self.gridLayoutWidget = QtGui.QWidget(self.centralwidget)
self.gridLayoutWidget.setGeometry(QtCore.QRect(10, 10, 771, 83))
self.gridLayoutWidget.setObjectName(_fromUtf8("gridLayoutWidget"))
self.gridLayout = QtGui.QGridLayout(self.gridLayoutWidget)
self.gridLayout.setMargin(0)
self.gridLayout.setObjectName(_fromUtf8("gridLayout"))
self.Button_Browse = QtGui.QPushButton(self.gridLayoutWidget)
self.Button_Browse.setObjectName(_fromUtf8("Button_Browse"))
self.gridLayout.addWidget(self.Button_Browse, 0, 0, 1, 1)
self.Button_Plot = QtGui.QPushButton(self.gridLayoutWidget)
self.Button_Plot.setObjectName(_fromUtf8("Button_Plot"))
self.gridLayout.addWidget(self.Button_Plot, 1, 0, 1, 1)
self.lineEdit = QtGui.QLineEdit(self.gridLayoutWidget)
self.lineEdit.setObjectName(_fromUtf8("lineEdit"))
self.gridLayout.addWidget(self.lineEdit, 0, 1, 1, 1)
self.Button_Clear = QtGui.QPushButton(self.gridLayoutWidget)
self.Button_Clear.setObjectName(_fromUtf8("Button_Clear"))
self.gridLayout.addWidget(self.Button_Clear, 2, 0, 1, 1)
self.label = QtGui.QLabel(self.centralwidget)
self.label.setGeometry(QtCore.QRect(20, 130, 61, 31))
self.label.setObjectName(_fromUtf8("label"))
self.label_2 = QtGui.QLabel(self.centralwidget)
self.label_2.setGeometry(QtCore.QRect(700, 130, 61, 31))
self.label_2.setObjectName(_fromUtf8("label_2"))
self.label_3 = QtGui.QLabel(self.centralwidget)
self.label_3.setGeometry(QtCore.QRect(20, 430, 61, 31))
self.label_3.setObjectName(_fromUtf8("label_3"))
self.label_4 = QtGui.QLabel(self.centralwidget)
self.label_4.setGeometry(QtCore.QRect(700, 430, 61, 31))
self.label_4.setObjectName(_fromUtf8("label_4"))
self.widget = matplotlibWidget(self.centralwidget)
self.widget.setGeometry(QtCore.QRect(90, 130, 571, 251))
self.widget.setObjectName(_fromUtf8("widget"))
self.widget_2 = matplotlibWidget2(self.centralwidget)
self.widget_2.setGeometry(QtCore.QRect(770, 130, 571, 251))
self.widget_2.setObjectName(_fromUtf8("widget_2"))
self.widget_3 = matplotlibWidget3(self.centralwidget)
self.widget_3.setGeometry(QtCore.QRect(90, 430, 571, 251))
self.widget_3.setObjectName(_fromUtf8("widget_3"))
self.widget_4 = matplotlibWidget4(self.centralwidget)
self.widget_4.setGeometry(QtCore.QRect(770, 430, 571, 251))
self.widget_4.setObjectName(_fromUtf8("widget_4"))
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtGui.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 1445, 21))
self.menubar.setObjectName(_fromUtf8("menubar"))
self.menuFile = QtGui.QMenu(self.menubar)
self.menuFile.setObjectName(_fromUtf8("menuFile"))
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtGui.QStatusBar(MainWindow)
self.statusbar.setObjectName(_fromUtf8("statusbar"))
MainWindow.setStatusBar(self.statusbar)
self.menubar.addAction(self.menuFile.menuAction())

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

def retranslateUi(self, MainWindow):
MainWindow.setWindowTitle(QtGui.QApplication.translate("MainWindow", "fsa Plotter", None, QtGui.QApplication.UnicodeUTF8))
self.Button_Browse.setText(QtGui.QApplication.translate("MainWindow", "Browse", None, QtGui.QApplication.UnicodeUTF8))
self.Button_Plot.setText(QtGui.QApplication.translate("MainWindow", "Plot", None, QtGui.QApplication.UnicodeUTF8))
self.Button_Clear.setText(QtGui.QApplication.translate("MainWindow", "Clear", None, QtGui.QApplication.UnicodeUTF8))
self.label.setText(QtGui.QApplication.translate("MainWindow", "Channel 1", None, QtGui.QApplication.UnicodeUTF8))
self.label_2.setText(QtGui.QApplication.translate("MainWindow", "Channel 2", None, QtGui.QApplication.UnicodeUTF8))
self.label_3.setText(QtGui.QApplication.translate("MainWindow", "Channel 3", None, QtGui.QApplication.UnicodeUTF8))
self.label_4.setText(QtGui.QApplication.translate("MainWindow", "Channel 4", None, QtGui.QApplication.UnicodeUTF8))
self.menuFile.setTitle(QtGui.QApplication.translate("MainWindow", "File", None, QtGui.QApplication.UnicodeUTF8))

from matplotlibwidget import matplotlibWidget
from matplotlibwidget3 import matplotlibWidget3
from matplotlibwidget2 import matplotlibWidget2
from matplotlibwidget4 import matplotlibWidget4

Answer

The file-dialog doesn't show, because you did not create an instance of your GUI_fsa class.

To fix that, make the following changes:

if __name__ == "__main__":

    app = QtGui.QApplication(sys.argv)
    MainWindow = GUI_fsa()
    # the next two lines aren't needed
    # ui = Ui_MainWindow()
    # ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

There is another problem you will also need to fix, in your Browse method. The widgets from Ui_MainWindow need to accessed via self.ui. So also make the following changes:

    def Browse(self):
        fname = QFileDialog.getOpenFileName()
        self.ui.lineEdit.setText(fname)
        ...

One final suggestion: avoid using the old-style syntax for connecting signals, and use the new-style syntax instead:

    # don't do this:
    # QtCore.QObject.connect(self.ui.Button_Browse, QtCore.SIGNAL('clicked()'), self.Browse)
    # do this!
    self.ui.Button_Browse.clicked.connect(self.Browse)
Comments