PyQt5：将信号从工作线程连接到MainWindow

Question

我正在将PyQt5用于GUI应用程序，其中在按下按钮后运行带有while循环的QThread。我想在我的MainWindow的状态栏中输出有关QThread类中的过程的一些信息。因此，我试图使用插槽和信号来连接两个线程。但是，状态栏不会更新。

我知道window.print_status("Executed loop")在此最小示例中有效，但不是很好的做法，在较大的应用程序中会崩溃。

我如何正确地将线程发出的信号连接到主窗口？

我附上一个最小的例子：

from PyQt5.QtWidgets import QMainWindow, QApplication
from PyQt5 import uic, QtCore, QtGui, QtWidgets
from os import mkdir,path
from time import sleep,strftime,localtime
from shutil import copytree

ui_path = path.dirname(path.abspath(__file__))
Ui_MainWindow, QtBaseClass = uic.loadUiType(path.join(ui_path, "minimal.ui"))

class Communication(QtCore.QObject):
    signal_str = QtCore.pyqtSignal(str)

class MyApp(QMainWindow):
    def __init__(self):
        super(MyApp, self).__init__()
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        self.ui.pushButton.clicked.connect(self.button_clicked)

    def button_clicked(self):
        print("Start pressed")

        self.Thread = WorkingThread()
        self.Thread.start()


    @QtCore.pyqtSlot(str)    
    def print_status(self,messagestring):
        print("Executing print_status with", messagestring)
        self.ui.statusbar.showMessage(messagestring)

class WorkingThread(QtCore.QThread):
    def __init__(self):
        QtCore.QThread.__init__(self)
        self.signals = Communication()
        self.signals.signal_str.connect(window.print_status)

    def __del__(self):
        self.wait()

    def run(self):

        #do something
        self.run = 1
        try:
            while self.run==1:
                #do some stuff in a loop
                #window.print_status("Executed loop")

                self.signals.print_status.emit("Hello World.")

                #sleep for a while and repeat
                sleep(30)
        except:
            return

if __name__ == '__main__':
    #sys.stdout = open(path.join(ui_path, "logFile.txt"), 'w')
    app = QApplication(sys.argv)
    window = MyApp()
    window.show()
    sys.exit(app.exec_())

这是我的ui文件：

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>800</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QLabel" name="label">
    <property name="geometry">
     <rect>
      <x>146</x>
      <y>176</y>
      <width>281</width>
      <height>81</height>
     </rect>
    </property>
    <property name="text">
     <string>Minimal Example</string>
    </property>
   </widget>
   <widget class="QPushButton" name="pushButton">
    <property name="geometry">
     <rect>
      <x>300</x>
      <y>170</y>
      <width>311</width>
      <height>101</height>
     </rect>
    </property>
    <property name="text">
     <string>PushButton</string>
    </property>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>800</width>
     <height>22</height>
    </rect>
   </property>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

Answer 1

我想我发现了我的错误：

代替使用：

self.signals.print_status.emit("Hello World.")

它应该是：

self.signals.signal_str.emit("Hello World.")