Transparently get backspace event in PyQt

问题:

I want to detect when backspace is pressed in a QPlainTextEdit widget.

I have the following code:

    def keyPressEvent(self, event):
        if event.key() == QtCore.Qt.Key_Backspace:
            print("Backspace pressed")

(in a class inherited from QPlainTextEdit)

The problem is that now pressing backspace (or any other character key) does not insert the character into the text box. I could check for every key and do it that way, however, especially with large files, removing the last character could be inefficient, slow and result in messy code.

Is there a better way of doing this?

回答1:

The keyPressEvent method of QPlainTextEdit already has a certain behavior that among other things is to add text, but when you overwrite it you are eliminating it, so the solution is to call the implementation of the parent not to eliminate that behavior

from PyQt5 import QtCore, QtWidgets

class PlainTextEdit(QtWidgets.QPlainTextEdit):
    def keyPressEvent(self, event):
        if event.key() == QtCore.Qt.Key_Backspace:
            print("Backspace pressed")
        super(PlainTextEdit, self).keyPressEvent(event)

if __name__ == '__main__':
    import sys
    app = QtWidgets.QApplication(sys.argv)
    w = PlainTextEdit()
    w.show()
    sys.exit(app.exec_())