Python 当按下鼠标时，如何将QLabel更改为QLineEdit？

我正在尝试创建一个自定义类，以便每当发生鼠标按下事件时，QLabel都应该更改为QLineEdit。所以，在搜索之后，我在Qt网站上找到了这段代码。但是，不幸的是，它不起作用。发布此问题的用户已接受此代码，但我对Qt和Python都是新手，所以我需要一些帮助

class nameDisplay(QtGui.QLabel):
    def __init__(self,buddyList,parent=None):
        QtGui.QLabel.__init__(self, parent)
        self.buddyList = buddyList

    def mousePressEvent(self, event):
        print 'mousePressEvent'
        self.buddyList.username.hide()
        self.buddyList.usernameInput = QtGui.QLineEdit(self.buddyList)
        self.buddyList.usernameInput.setGeometry(QtCore.QRect(120, 10, 121, 20))
        self.buddyList.usernameInput.setText(self.buddyList.username.text())
        self.buddyList.usernameInput.selectAll()
        self.buddyList.usernameInput.show()
        self.connect(self.buddyList.usernameInput,QtCore.SIGNAL("returnPressed()"),self.editingFinish)

    def editingFinish(self):
        self.buddyList.usernameInput.hide()
        self.buddyList.username.show()
        self.buddyList.username.setText(self.buddyList.usernameInput.text())

更新：

我得到的错误是：

# Error: line 1: __init__() takes at least 2 arguments (1 given)
# Traceback (most recent call last):
#   File "<maya console>", line 22, in <module>
# TypeError: __init__() takes at least 2 arguments (1 given) # 

---

下面是一个如何让Qlabel切换到QLineEdit的示例。或者，当字段留空时，可以使用QLineEdit.setPlaceholderText显示一些默认文本。这可能是另一个供您使用的选项，并且将更加简单

from PySide import QtGui, QtCore

# Make a custom label widget (mostly for its mousePressEvent)
class BuddyLabel(QtGui.QLabel):
    def __init__(self, buddy, parent = None):
        super(BuddyLabel, self).__init__(parent)
        self.buddy = buddy

    # When it's clicked, hide itself and show its buddy
    def mousePressEvent(self, event):
        self.hide()
        self.buddy.show()
        self.buddy.setFocus() # Set focus on buddy so user doesn't have to click again

class Window(QtGui.QWidget):
    def __init__(self, parent = None):
        super(Window, self).__init__(parent)

        # Create ui
        self.myEdit = QtGui.QLineEdit()
        self.myEdit.hide() # Hide line edit
        self.myEdit.editingFinished.connect(self.textEdited)
        self.myLabel = BuddyLabel(self.myEdit) # Create our custom label, and assign myEdit as its buddy
        self.myLabel.setText('Nothing has been entered')
        self.myLabel.setSizePolicy(QtGui.QSizePolicy.Preferred, QtGui.QSizePolicy.Fixed) # Change vertical size policy so they both match and you don't get popping when switching

        # Put them under a layout together
        hLayout = QtGui.QHBoxLayout()
        hLayout.addWidget(self.myLabel)
        hLayout.addWidget(self.myEdit)

        # Add a line edit with a place holder
        self.myEdit2 = QtGui.QLineEdit()
        self.myEdit2.setPlaceholderText('Nothing has been entered')
        self.setFocus() # By default this line edit may have focus and the place holder won't show up on load, so focus on the widget

        # Create main layout
        mainLayout = QtGui.QVBoxLayout()
        mainLayout.addLayout(hLayout)
        mainLayout.addWidget(self.myEdit2)
        self.setLayout(mainLayout)

        # Resize and show!
        self.resize(300, 200)
        self.show()

    def textEdited(self):
        # If the input is left empty, revert back to the label showing
        if not self.myEdit.text():
            self.myEdit.hide()
            self.myLabel.show()

win = Window()

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寻求调试帮助的问题代码为什么不工作？必须包括所需的行为、特定的问题或错误以及在问题本身中重现这些问题所需的最短代码。看看怎么做。谢谢你的回复。这正是我想要的。你能给我推荐一些pyqt教程吗？我不知道如何学习pyqt教程。只要经常使用谷歌搜索例子就可以了。