Python PyQt4如何使用QFileDialog打开图像

Question

I have to write a program with an option to open an image from a file. I have to use QFileDialog and display image in QLabel , using QPixmap . I am able to use them individually but I didn't manage to combine them. I think I need to take my image name from dlg.selectedFiles but I don't know how to choose the moment when there is useful data in it. Do I need to make a loop in my main program, and constantly check if there is image to open? Can I send a signal to my label using openAction.triggered.connect(...) ?

from PyQt4 import QtGui
import sys

class MainWindow(QtGui.QMainWindow):

    def __init__(self, parent = None):
        super(MainWindow, self).__init__(parent)
        menubar = self.menuBar()
        fileMenu = menubar.addMenu('File')
        dlg = QtGui.QFileDialog(self)       
        openAction = QtGui.QAction('Open', self)  
        openAction.triggered.connect(dlg.open)     
        fileMenu.addAction(openAction)
        #label = QtGui.QLabel(self)
        #pixmap = QtGui.QPixmap('')
        #label.setPixmap(pixmap)

def main():
    app = QtGui.QApplication(sys.argv)
    win = MainWindow()
    win.show()
    app.exec_()

if __name__ == '__main__':
    sys.exit(main()) 

Answer 1

You need to make your own slot and connect it to the openAction signal.
In your __init__ function do:

openAction.triggered.connect(self.openSlot)  

In your class MainWindow define the following function:

def openSlot(self):
    # This function is called when the user clicks File->Open.
    filename = QtGui.QFileDialog.getOpenFileName()
    print(filename)
    # Do your pixmap stuff here.