我试图围绕如何正确使用PyQt5和Python3的线程和信号，但不知何故无法理解这一切是如何运作的。我在这里找到了一个示例代码，现在正尝试在PyQt5中使用它。
这是gui文件ui.py：
from PyQt5 import QtCore, QtWidgets
class Ui_Win(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(416, 292)
self.centralWidget = QtWidgets.QWidget(MainWindow)
self.centralWidget.setObjectName("centralWidget")
MainWindow.setCentralWidget(self.centralWidget)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Ui_Win()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
这是主要的脚本test_slotting.py：
from ui import Ui_Win
from PyQt5 import QtGui, QtCore, QtWidgets
from PyQt5.QtCore import pyqtSlot
import time
class GenericThread(QtCore.QThread):
def __init__(self, parent=None):
QtCore.QThread.__init__(self, parent)
def __del__(self):
self.quit()
self.wait()
def run(self):
#Do all your heavy processing here
#I'll just wait for 2 seconds
time.sleep(2)
self.emit(QtCore.pyqtSignal('itemSelectionChanged()'))
return
class MainUI(QtWidgets.QMainWindow):
def __init__(self, parent=None):
QtWidgets.QMainWindow.__init__(self)
self.ui = Ui_Win()
self.ui.setupUi(self)
self.ui.List1 = QtWidgets.QListWidget(self)
self.ui.List2 = QtWidgets.QListWidget(self)
hbox = QtWidgets.QHBoxLayout()
hbox.addStretch(1)
hbox.addWidget(self.ui.List1)
hbox.addWidget(self.ui.List2)
self.ui.centralWidget.setLayout(hbox)
self.ui.List1.addItems(['alpha','beta','gamma','delta','epsilon'])
self.ui.List2.addItems(['Item1','Item2'])
self.ui.List1.itemSelectionChanged.connect(self.start_heavy_processing_thread)
@pyqtSlot()
def start_heavy_processing_thread(self):
genericThread = GenericThread(self)
# self.connect(genericThread, QtCore.SIGNAL("itemSelectionChanged()"), self.fill_List2 )
genericThread.itemSelectionChanged.connect(self.fill_List2)
genericThread.start()
def fill_List2(self):
self.ui.List2.clear()
list1SelectedItem = str(self.ui.List1.currentItem().text())
self.ui.List2.addItem(list1SelectedItem)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = MainUI()
MainWindow.show()
sys.exit(app.exec_())
从最初的代码示例中，我不得不改变旧样式＆＃34;
self.connect(genericThread, QtCore.SIGNAL("itemSelectionChanged()"), self.fill_List2 )
到＆＃34;新风格＆＃34;
self.ui.List1.itemSelectionChanged.connect(self.start_heavy_processing_thread)
但是，现在我得到以下AttributeError: 'GenericThread' object has no attribute 'itemSelectionChanged'。我想test_slotting.py中的这一行仍然是＃34;旧式＆＃34;：
self.emit(QtCore.pyqtSignal('itemSelectionChanged()'))
但它的新款式是什么？任何帮助将不胜感激......
答案 0 :(得分：2)
错误是非常期待的。您的GenericThread没有名为itemSelectionChanged()的信号，因此您无法将不存在的信号连接到插槽。此信号属于您的QListWidget，而不属于您的GenericThread。
在您决定创建自定义帐号之前，我建议您详细了解QThread的工作原理。特别是如果你的那个帖子与插槽和信号一起工作，你实际上进行了重复处理＆＃34;，由于QThread的性质，你会被搞砸 - 只有run()里面的内容{{} 1}}实际上在一个单独的线程内运行。其余的（插槽，信号，类成员等）属于您从中生成自己的QThread的线程 - 在您的情况下，这是主线程。
我上传了一个使用PyQt和线程here的示例，您可以在其中查看通常如何完成的事情。我也在那里使用新风格。
关于新风格的简短说明：
我们假设你有一个QWidget派生类，其中QPushButton名为button，而do_work()就是你想要触发的时段self.button.clicked.connect(self.do_work)
| | | |
| | | |
| signal of emitter | slot of receiver
| |
signal emitter signal receiver
单击按钮。要建立此连接，您必须执行以下操作：
self在这种情况下，self.do_work是接收者，因此我们使用do_work来说明广告符self属于clicked，并且信号button所在的位置fill_List2()由<html>
<head>
<style>
@font-face {
font-family: 'NotoEmoji-Regular';
src: url('NotoEmoji-Regular.ttf') format('truetype');
unicode-range: U+1F300-1F5FF, U+1F600-1F64F, U+1F680-1F6FF, U+2600-26FF;
}
body{
font-family: "NotoEmoji-Regular", "Roboto", sans-serif !important;
color: red;
}
</style>
</head>
<body>
Chain <br/>
◉ Dot <br/>
Group <br/>
Person <br/>
Folder <br/>
Eye <br/>
Scroll <br/>
Tools <br/>
</body>
</html>
发出的1}}必须降落。
PS：我注意到你试图使用装饰器，但只是部分地这样做。如果您想使用这些（我强烈建议您这样做），您需要在TreeSet<Product> orderList = new TreeSet<>(new Comparator<Product>() {
@Override
public int compare(Product prod1, Product prod2) {
return prod1.getNumber().compareTo(prod2.getNumber());
}
});
orderList.addAll(result);
函数中添加一个插槽装饰器。
答案 1 :(得分：0)
更新后的代码
<强> ui.py：
from PyQt5 import QtWidgets
class Ui_Win(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(416, 292)
self.centralWidget = QtWidgets.QWidget(MainWindow)
self.centralWidget.setObjectName("centralWidget")
MainWindow.setCentralWidget(self.centralWidget)
self.List1 = QtWidgets.QListWidget()
self.List2 = QtWidgets.QListWidget()
self.hbox = QtWidgets.QHBoxLayout()
self.hbox.addStretch(1)
self.hbox.addWidget(self.List1)
self.hbox.addWidget(self.List2)
self.centralWidget.setLayout(self.hbox)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Ui_Win()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
<强> test_slotting.py：
from ui import Ui_Win
from PyQt5 import QtWidgets, QtCore
from PyQt5.QtCore import pyqtSlot, pyqtSignal, QObject
class Trigger(QObject): # --> or QtCore.QThread? What's the difference?
trigger = pyqtSignal()
def connect_emit(self, pressed_item, list_to_update):
self.pressed_item = pressed_item # --> this kind of looks ugly to me... hmmm...
self.list_to_update = list_to_update # --> this kind of looks ugly to me... hmmm...
self.trigger.connect(self.run)
self.trigger.emit()
def run(self):
self.list_to_update.clear()
self.list_to_update.addItem(self.pressed_item)
class MainUI(QtWidgets.QMainWindow):
def __init__(self, parent=None):
QtWidgets.QMainWindow.__init__(self)
self.ui = Ui_Win()
self.ui.setupUi(self)
self.ui.List1.addItems(['alpha', 'beta', 'gamma', 'delta', 'epsilon'])
self.ui.List2.addItems(['Item1', 'Item2'])
self.ui.List1.itemSelectionChanged.connect(self.start_heavy_processing_thread)
@pyqtSlot() # --> what does this actually do? code also works without it...
def start_heavy_processing_thread(self):
genericThread = Trigger()
myitem = [str(x.text()) for x in self.ui.List1.selectedItems()][0]
mylist = self.ui.List2
genericThread.connect_emit(myitem, mylist)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = MainUI()
MainWindow.show()
sys.exit(app.exec_())