如何从 Python 中的 Main class 调用 GUI 函数？

Question

我需要 my_app 中的 ProgressBar 小部件，当我点击 pushButton 时，我无法在 def download (self) 中调用 def call_progressBar2(self,value1)。谁能帮帮我？

main.py

from g import Ui_MainWindow
from PyQt4 import QtCore, QtGui
import sys
import time
from b import classb

class MainWindow(QtGui.QMainWindow):
    def __init__(self, parent=None):
        QtGui.QWidget.__init__(self, parent)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        instance_b=classb()
        tvt= self.call_progressBar2(self)
        QtCore.QObject.connect(self.ui.pushButton1, QtCore.SIGNAL("clicked()"), \
                       lambda: instance_b.download(tvt))## I need  help here.


    def call_progressBar2(self,value1): 
        while True:
            time.sleep(0.05)
            value = self.ui.progressBar.value() + 1
            self.ui.progressBar.setValue(value)
            QtGui.qApp.processEvents()
            if (not self.ui._active or
                value >= self.progressBar.maximum()):
                if value==value1:
                    break
        self.ui._active = False            

if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    myapp = MainWindow()
    myapp.show()
    sys.exit(app.exec_())

b.py

import time
from PyQt4 import QtCore, QtGui

class classb (object):
    def __init__(self, parent=None):
       self.parent=parent

#I need call def call_progressBar2() here.
    def download(self):
       from main import MainWindow 
       instance_m= MainWindow
       print 'a'
       instance_m.call_progressBar2(20)
       print 'b'
       instance_m.call_progressBar2(40)
       print 'c'
       instance_m.call_progressBar2(60)
       print 'd'
       instance_m.call_progressBar2(100)

Answer 1

为什么不在连接信号时将当前 MainWindow 实例传递给 download 函数？或者在连接信号之前实例化它时将它传递给 classb 初始化程序？或者指定 download 以便它接受回调，并在连接信号时将 MainWindow 当前实例的 call_progressBar2 方法作为回调传递 ?

Answer 2

不是在 classb.download 方法中创建 MainWindow 的实例，而是在连接信号时将其作为参数传递，这样：

#tvt= self.call_progressBar2(self) #No need for tvt
QtCore.QObject.connect(self.ui.pushButton1, QtCore.SIGNAL("clicked()"), \
                       lambda: instance_b.download(self)) #self here is the MainWindow Instance

然后在classb.download方法中：

def download(self, main_window):
    print 'a'
    main_window.call_progressBar2(20)
    print 'b'
    main_window.call_progressBar2(40)
    print 'c'
    main_window.call_progressBar2(60)
    print 'd'
    main_window.call_progressBar2(100)

如何从 Python 中的 Main class 调用 GUI 函数？

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