单击事件时清除 QLineEdit

Question

我正在使用给定的代码，我希望用户在 QLineEdit 小部件中输入文本，按复制！按钮并查看输入的文本替换“N/A”标签。我的问题是：按照此过程，如何通过简单的鼠标单击清除 QLineEdit 小部件中输入的文本？

从我读到的（this、this和this）来看，我似乎需要在扩展 QLineEdit 的新类中重新实现 focusInEvent()。我的问题是我的 GUI 代码是使用 pyuic5 从 Qt Designer 导入的，上面引用的示例似乎没有考虑到这一点。

这是我的代码：

from PyQt5.QtWidgets import *
import sys

import QLineEdit_test


class MainWindow(QMainWindow, QLineEdit_test.Ui_QLineEdit_test):

    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)
        self.setupUi(self)

        self.copy_button.clicked.connect(self.copy_and_print)

    def copy_and_print(self):

        self.label.setText(self.lineEdit.text())


def main():

    app = QApplication(sys.argv)
    form = MainWindow()
    form.show()
    app.exec_()

if __name__ == "__main__":
    main()

这是我转换后的 .ui 文件：

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_QLineEdit_test(object):
    def setupUi(self, QLineEdit_test):
        QLineEdit_test.setObjectName("QLineEdit_test")
        QLineEdit_test.resize(300, 200)
        QLineEdit_test.setMaximumSize(QtCore.QSize(300, 200))
        self.centralwidget = QtWidgets.QWidget(QLineEdit_test)
        self.centralwidget.setObjectName("centralwidget")
        self.gridLayout_2 = QtWidgets.QGridLayout(self.centralwidget)
        self.gridLayout_2.setObjectName("gridLayout_2")
        self.gridLayout = QtWidgets.QGridLayout()
        self.gridLayout.setObjectName("gridLayout")
        self.lineEdit = QtWidgets.QLineEdit(self.centralwidget)
        self.lineEdit.setMaximumSize(QtCore.QSize(120, 16777215))
        self.lineEdit.setObjectName("lineEdit")
        self.gridLayout.addWidget(self.lineEdit, 0, 0, 1, 1)
        self.copy_button = QtWidgets.QPushButton(self.centralwidget)
        self.copy_button.setObjectName("copy_button")
        self.gridLayout.addWidget(self.copy_button, 1, 0, 1, 1)
        self.label = QtWidgets.QLabel(self.centralwidget)
        self.label.setMaximumSize(QtCore.QSize(200, 20))
        self.label.setAlignment(QtCore.Qt.AlignCenter)
        self.label.setObjectName("label")
        self.gridLayout.addWidget(self.label, 2, 0, 1, 1)
        self.gridLayout_2.addLayout(self.gridLayout, 0, 0, 1, 1)
        QLineEdit_test.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(QLineEdit_test)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 300, 22))
        self.menubar.setObjectName("menubar")
        QLineEdit_test.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(QLineEdit_test)
        self.statusbar.setObjectName("statusbar")
        QLineEdit_test.setStatusBar(self.statusbar)

        self.retranslateUi(QLineEdit_test)
        QtCore.QMetaObject.connectSlotsByName(QLineEdit_test)

    def retranslateUi(self, QLineEdit_test):
        _translate = QtCore.QCoreApplication.translate
        QLineEdit_test.setWindowTitle(_translate("QLineEdit_test", "MainWindow"))
        self.copy_button.setText(_translate("QLineEdit_test", "Copy!"))
        self.copy_button.setShortcut(_translate("QLineEdit_test", "Return"))
        self.label.setText(_translate("QLineEdit_test", "N/A"))

Answer 1

解决方案是提升 QtDesigner 使用我们自定义的 QLineEdit，我们在 mousePressEvent 的帮助下实现点击的信号，这个类将被称为 ClickableLineEdit，文件将被称为 ClickableLineEdit.py。

ClickableLineEdit.py

from PyQt5.QtCore import pyqtSignal
from PyQt5.QtWidgets import QLineEdit


class ClickableLineEdit(QLineEdit):
    clicked = pyqtSignal()
    def mousePressEvent(self, event):
        self.clicked.emit()
        QLineEdit.mousePressEvent(self, event)

为了促进它，将考虑以下结构：

.
??? ClickableLineEdit.py
??? main.py  
??? your.ui
??? QLineEdit_test.py

使用 Qt Designer 打开设计并右键单击 QLineEdit 并选择Promote to ...：

将打开一个菜单并放置以下内容

然后按并推广。然后我们再次生成代码。

然后我们连接信号清除：

class MainWindow(QMainWindow, QLineEdit_test.Ui_QLineEdit_test):

    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)
        self.setupUi(self)

        self.copy_button.clicked.connect(self.copy_and_print)
        self.lineEdit.clicked.connect(self.lineEdit.clear)

    def copy_and_print(self):
        self.label.setText(self.lineEdit.text())

更新：

PySide2：

from PyQt5.QtCore import pyqtSignal
from PyQt5.QtWidgets import QLineEdit


class ClickableLineEdit(QLineEdit):
    clicked = pyqtSignal()
    def mousePressEvent(self, event):
        self.clicked.emit()
        QLineEdit.mousePressEvent(self, event)