Question

我想将文件拖放到listwidget上，然后在itemactivated，plaintextedit打开并在文件中插入readAll行时。但返回错误："connect() failed between itemActivated(QListWidgetItem*) and read_txt()"

from PyQt5 import QtCore, QtGui, QtWidgets
import sys


class Ui_MainWindow(object):

    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(873, 663)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        MainWindow.setCentralWidget(self.centralwidget)

        self.listWidget = listWidget(self.centralwidget)
        self.listWidget.setGeometry(QtCore.QRect(150, 330, 256, 192))
        self.listWidget.setObjectName("listWidget")

        self.plainTextEdit = QtWidgets.QPlainTextEdit(self.centralwidget)
        self.plainTextEdit.setGeometry(QtCore.QRect(440, 200, 104, 87))
        self.plainTextEdit.setObjectName("plainTextEdit")

        self.listWidget.itemActivated.connect(self.read_txt)

        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    @QtCore.pyqtSlot("QListWidgetItem*")
    def read_txt(self,links):

        file = QtCore.QFile(links.text())
        if file.open(QtCore.QFile.ReadOnly | QtCore.QFile.Text):
            self.plainTextEdit.setPlainText(file.readAll().data().decode())            
class listWidget(QtWidgets.QListWidget):
    def __init__(self, parent):
        super().__init__(parent)   
        self.setAcceptDrops(True)

    def dragEnterEvent(self, event):

        if event.mimeData().hasUrls:

            event.acceptProposedAction()
        else:
            event.ignore() 

    def dragMoveEvent(self, event):
        if event.mimeData().hasUrls:
            event.setDropAction(QtCore.Qt.CopyAction)
            event.acceptProposedAction()
        else:
            event.ignore()
    def dropEvent(self, event):

        if event.mimeData().hasUrls:
            event.setDropAction(QtCore.Qt.CopyAction)

            for url in event.mimeData().urls():
                links=QtWidgets.QListWidgetItem(url.toLocalFile())

            self.addItem(links)
            event.acceptProposedAction()   


if __name__ == "__main__":


    if not QtWidgets.QApplication.instance():
        app = QtWidgets.QApplication(sys.argv)
    else:
        app = QtWidgets.QApplication.instance() 



    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    app.exec_()

拖放工作正常，但无法使用QListWidgetItem中的readtxt方法连接setupUi。有什么问题??

Answer 1

问题是@pyqtSlot装饰器只能用于从QObject继承的类中。您可以将信号连接到任何可调用对象，因此最简单的方法就是省略装饰器，但是如果出于某种原因确实需要装饰器，则可以继承QMainWindow并在其中定义插槽，例如

class MyMainWindow(QtWidgets.QMainWindow):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        self.ui.listWidget.itemActivated.connect(self.read_txt)

    @QtCore.pyqtSlot("QListWidgetItem*")
    def read_txt(self, links):
        file = QtCore.QFile(links.text())
        if file.open(QtCore.QFile.ReadOnly | QtCore.QFile.Text):
            self.ui.plainTextEdit.setPlainText(file.readAll().data().decode())


if __name__ == '__main__':
    ...
    mainWindow = MyMainWindow()
    mainWindow.show()
    ...

在setupUI中连接QListWidgetItem

1 个答案: