pyqt：如何在外部变量值更改时动态更新小部件属性？

Question

我有class Ui_MainWindow(object)创建一个带有进度条的窗口，还有class OtherClass(object)包含局部int变量在循环中递增的方法。

如何将局部变量值更改连接到程序条值更改？

主界面.py

import sys
from PyQt4.uic.Compiler.qtproxies import QtGui
from PyQt4 import QtGui
from Ui_MainWindow import Ui_MainWindow

def main():

    app = QtGui.QApplication(sys.argv)
    MainWindow = QtGui.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())



if __name__ == '__main__':
    main()

用户界面主窗口.py

from PyQt4 import QtCore, QtGui
from MainGui.OtherClass import OtherClass

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

class Ui_MainWindow(object):

    def myButtonSlot(self):
        objVar=OtherClass()
        objVar.method()

    def setupUi(self, MainWindow):
        MainWindow.setObjectName(_fromUtf8("MainWindow"))
        MainWindow.resize(389, 332)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.verticalLayout = QtGui.QVBoxLayout(self.centralwidget)
        self.verticalLayout.setObjectName(_fromUtf8("verticalLayout"))

        self.pushButton = QtGui.QPushButton(self.centralwidget)
        self.pushButton.setObjectName(_fromUtf8("pushButton"))
        self.pushButton.clicked.connect(self.myButtonSlot)
        self.verticalLayout.addWidget(self.pushButton)

        self.progressBar = QtGui.QProgressBar(self.centralwidget) 
        self.progressBar.setProperty("value", 24)
        self.progressBar.setObjectName(_fromUtf8("progressBar"))

        self.verticalLayout.addWidget(self.progressBar)
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtGui.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 389, 21))
        self.menubar.setObjectName(_fromUtf8("menubar"))
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtGui.QStatusBar(MainWindow)
        self.statusbar.setObjectName(_fromUtf8("statusbar"))
        MainWindow.setStatusBar(self.statusbar)

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

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

其他类.py

class OtherClass(object):  
    def method(self):
        for i in range(100): # i want to connect variable i to progress bar value
            print i 
            for j in range(100500):
                pass

Answer 1

下面的文章有一个版本，每次按下按钮，进度条都会增加10%。以及使用计时器增加进度条的版本。（我自己正在学习）

在Qt设计器中，添加进度条和按钮。单击“编辑信号/插槽”，将一行从按钮拖到窗口中的某个位置，当按钮被“pressed（）”时，添加一个插槽（或信号？？）称为“button_pressed（）”（使用+按钮进行此操作）。完成此操作后，“确定”按钮将灰显-选择您创建的插槽，然后按“确定”。

将文件另存为ui_MainWindow.ui（注意大写字母）。 使用批处理文件转换为py文件>

pyuic4 -x ui_MainWindow.ui -o ui_MainWindow.py

这个文件应该看起来像…（你不需要编辑这个）。

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_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName(_fromUtf8("MainWindow"))
        MainWindow.resize(800, 600)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.progressBar = QtGui.QProgressBar(self.centralwidget)
        self.progressBar.setGeometry(QtCore.QRect(110, 90, 118, 23))
        self.progressBar.setProperty("value", 24)
        self.progressBar.setObjectName(_fromUtf8("progressBar"))
        self.pushButton = QtGui.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(120, 200, 75, 23))
        self.pushButton.setObjectName(_fromUtf8("pushButton"))
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtGui.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 21))
        self.menubar.setObjectName(_fromUtf8("menubar"))
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtGui.QStatusBar(MainWindow)
        self.statusbar.setObjectName(_fromUtf8("statusbar"))
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        QtCore.QObject.connect(self.pushButton, QtCore.SIGNAL(_fromUtf8("pressed()")), MainWindow.button_pressed)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow", None))
        self.pushButton.setText(_translate("MainWindow", "PushButton", None))


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

创建“program.py”文件。这是你要运行的文件。。。

import sys
from PyQt4 import QtGui
#from PyQt5 import QtCore, QtGui, QtWidgets #works for pyqt5
from mainWindow import MainWindow

def main():
    #app = QtWidgets.QApplication (sys.argv) #works for pyqt5
    app = QtGui.QApplication (sys.argv) #works for pyqt4
    m = MainWindow ()
    m.show ()
    sys.exit (app.exec_ () )

if __name__ == '__main__':
    main ()

现在，当你对主窗口进行子类化时，好的事情就发生在这里。将此文件称为“mainWindow.py”。小心资本化。

from PyQt4 import QtCore, QtGui
from ui_MainWindow import Ui_MainWindow #note the capitalization

class MainWindow (QtGui.QMainWindow):
    def __init__ (self, parent = None):
        super (MainWindow, self).__init__ ()
        self.ui = Ui_MainWindow ()
        self.ui.setupUi (self)
        #------------do your custom stuff from here on-----------
        self.progress = 0 #Start value of progress bar
        self.ui.progressBar.setValue(self.progress)

    def button_pressed(self):
        print('button pressed')
        self.ui.statusbar.showMessage(str(self.progress)) #this is at bottom left of window. Discovered this accidentially when doing this!
        self.ui.progressBar.setValue(self.progress)
        self.progress+=10

有一个很好的教程here，我用它来创建一个备用的'mainWindow.py'，它使用一个计时器来增加进度条。它不会使用sleep循环或CPU密集型循环来阻塞代码。我不明白多线程，多处理器的选择，还没有评论使用这些。

#from PyQt5 import QtCore, QtGui, QtWidgets #works for PyQt5
from PyQt4 import QtCore, QtGui
from ui_MainWindow import Ui_MainWindow #note the capitalization

class MainWindow (QtGui.QMainWindow):
    def __init__ (self, parent = None):
        super (MainWindow, self).__init__ ()
        self.ui = Ui_MainWindow () #same name as appears in mainWindowUi.py
        self.ui.setupUi (self)
        self.progress = 0 #Start value of progress bar
        self.ui.progressBar.setValue(self.progress)

        self.timer = QtCore.QBasicTimer()

    def button_pressed(self):
        self.timerEvent(64) #this needs an argument to work but I'm not sure what is is yet so I just put in some random number

    def timerEvent(self, e):
        self.ui.progressBar.setValue(self.progress)
        if self.progress >=100:
            self.timer.stop()
       else:
            if self.timer.isActive():
                pass
            else:
                self.timer.start(10,self) #10 milliseconds
        self.progress+=1