在 PyQt4 中使用 QThread 运行线程时更新变量值

Question

所以当我尝试在我的代码中使用Threading 时出现了问题。我想要做的是将默认值传递给def __init__，然后使用其实例调用具有更新值的线程，但不知何故我无法获得更新的值。

下面是我的初始代码：ma​​in .py

from PyQt4 import QtGui
import sys
import GUI # GUI app by using PYQT4
from PyQt4.QtCore import QThread
#import Photos

class PyMain(QtGui.QWidget, GUI.Ui_Pycloud):
    def __init__(self):
        super(self.__class__, self).__init__()
        self.setupUi(self)
        self.password.setEchoMode(QtGui.QLineEdit.Password)

        """Picking up data from GUI.py file where initially,
        it is set to 'Username' and 'Password' respectively.
        and initialising `GetThread` class"""
        self.get_thread = GetThread(str(self.username.text()), 
                                    str(self.password.text())
                                   )
        """This is what I was initially using.
           I have tried, only passing the instance and calling 
           get_thread.start() inside __init__ fn but even if i don't click 
           `commandLinkButton` it is somehow called automatically.
           I know it is not the right approach"""
        self.commandLinkButton.clicked.connect(self.get_thread.start)


class GetThread(QThread):

    def __init__(self, username, password):
        QThread.__init__(self)
        self.username = username
        self.password = password

    def __del__(self):
        self.wait()

    def authentication(self):
        print self.username, self.password
        # user = Photos.PyPhotos(self.username, self.password)
        # user.authentication(user)

    def run(self):
        self.authentication()


def main():
    app = QtGui.QApplication(sys.argv)
    form = PyMain()
    form.show()
    app.exec_()

if __name__ == '__main__':
    main()

以下是我尝试过的：

...........................
...........................
...........................

class PyMain(QtGui.QWidget, GUI.Ui_Pycloud):
  def __init__(self):
    super(self.__class__, self).__init__()
    self.setupUi(self)
    self.password.setEchoMode(QtGui.QLineEdit.Password)
    self.commandLinkButton.clicked.connect(GetThread(str(self.username.text()), 
                                             str(self.password.text())).__init__)

class GetThread(QThread):

 def __init__(self, username, password):
        QThread.__init__(self)
        self.username = username
        self.password = password
        self.start()
...........................
...........................
...........................

结果： Username Password

当我运行我的main.py 文件时会显示它，而我应该得到这个只有当我按下commandLinkButton 并且如果我在我的 GUI 上更新它们没有发生时应该更新变量。

编辑：以下是我再次尝试的方法，如果我在 GUI 上更新它们，它会向我显示正确的输出，但在这种情况下线程不起作用：

..............
..............
..............
class PyMain(QtGui.QWidget, GUI.Ui_Pycloud):
    def __init__(self):
        super(self.__class__, self).__init__()
        self.setupUi(self)
        self.password.setEchoMode(QtGui.QLineEdit.Password)
        self.commandLinkButton.clicked.connect(self.populate)

    def populate(self):
        get_thread = GetThread(str(self.username.text()), str(self.password.text()))
        get_thread.start()


class GetThread(QThread):

    def __init__(self, username, password):
        QThread.__init__(self)
        self.username = username
        self.password = password

    def __del__(self):
        self.wait()

    def authentication(self):
        print self.username, self.password
        user = Photos.PyPhotos(self.username, self.password)
        user.authentication(user)

    def run(self):
        self.authentication()
......................
......................
......................

那么任何人都可以请告诉我如何处理这个问题？

Answer 1

您需要使用自定义信号将身份验证结果发送回主线程。但请注意，您不得在主线程之外执行任何类型的 gui 操作。因此，例如，工作线程无法显示身份验证对话框或尝试直接更新小部件。它所能做的就是执行一个冗长的非 gui 进程，并在完成后将结果发送回主线程。

代码的基本结构应该是这样的：

class PyMain(QtGui.QWidget, GUI.Ui_Pycloud):
    def __init__(self):
        super(self.__class__, self).__init__()
        self.setupUi(self)
        self.password.setEchoMode(QtGui.QLineEdit.Password)
        self.commandLinkButton.clicked.connect(self.populate)

    def populate(self):
        self.thread = GetThread(self.username.text(), self.password.text())
        self.thread.authResult.connect(self.handleAuthResult)
        self.thread.start()

    def handleAuthResult(self, result):
        # do something with result...

class GetThread(QThread):
    authResult = QtCore.pyqtSignal(object)

    def __init__(self, username, password):
        QThread.__init__(self)
        self.username = username
        self.password = password

    def authentication(self):
        result = do_authentication()
        self.authResult.emit(result)

    def run(self):
        self.authentication()