pyqt4中的线程错误

Question

I have the problem. I made the thread and from there I want to open the new window. But it does not work.

import sys
from grab import Grab
from PyQt4 import QtGui, QtCore
class Requests(QtCore.QThread):
    def __init__(self, parent=None):
        QtCore.QThread.__init__(self, parent)

    def run(self):
        # here some comands
        self.emit(QtCore.SIGNAL("mysignal(QString)"), 'open')

class window(QtGui.QWidget):
    def __init__(self, parent = None):
        QtGui.QWidget.__init__(self, parent)

        self.setGeometry(100, 100, 500, 200)
        self.setWindowTitle('Window')
        self.label = QtGui.QLabel(u'Hello')
        self.Layout = QtGui.QVBoxLayout()
        self.Layout.addWidget(self.label)
        self.setLayout(self.Layout)

        self.c = Requests()
        self.c.start()
        self.connect(self.c, QtCore.SIGNAL("mysignal(QString)"), self.open_window, QtCore.Qt.QueuedConnection)

    def open_window(self):
        print 'open modal window'
        modal_w = popup_window()
        modal_w.show()

app = QtGui.QApplication(sys.argv)
main = window()
main.show()
sys.exit(app.exec_())

It is not show new window. Where is the error?

Answer 1

You need to connect the signal before the thread starts, and hence before the signal is emitted. If you want to show a dialog when the worker thread completes, just use the finished signal:

class Requests(QtCore.QThread):    
    def run(self):
        # do some work...
        print 'work finished'

    ...
    self.c = Requests()
    self.c.finished.connect(self.open_window)
    self.c.start()

You also need to keep a reference to the dialog when opening it in the slot:

    def open_window(self):
        print 'open modal window'
        self.modal_w = popup_window()
        self.modal_w.show()