QlineEdit 和信号&槽

Question

我用QLineEdit 和QLabel 创建了一个小部件，我想从QlineEdit 获取输入并用QLabel 显示它。我使用了信号和插槽连接，我不知道我做错了什么，但它不能正常工作。我想从QLineEdit 获取这两个值，然后再显示。

当前窗口

我想要什么？

代码：

import os
import sys
from PyQt5 import QtCore, QtGui, QtWidgets

class WinDialog(QtWidgets.QDialog):

    currenttextedited = QtCore.pyqtSignal(int)

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

        self.setGeometry(300,300,350,300)

        self.setWindowTitle("Signal & Slot")

        self.propertyWidget = PropertyWidget()

        section_lay = QtWidgets.QHBoxLayout()
        section_label = QtWidgets.QLabel("Name: ")
        section_edit = QtWidgets.QLineEdit('')

        length_lay = QtWidgets.QHBoxLayout()
        length_label = QtWidgets.QLabel("Input a number:     L = ")
        self.length_edit = QtWidgets.QLineEdit('1000')
        self.length_edit.setInputMask("999999")
        self.length_edit.setFocus(True)

        thick_lay = QtWidgets.QHBoxLayout()
        thick_label = QtWidgets.QLabel("Input a text: T = ")
        thick_edit = QtWidgets.QLineEdit('')

        section_lay.addWidget(section_label)
        section_lay.addWidget(section_edit)

        length_lay.addWidget(length_label)
        length_lay.addWidget(self.length_edit)
        length_lay.addStretch()

        thick_lay.addWidget(thick_label)
        thick_lay.addWidget(thick_edit)
        thick_lay.addStretch()

        VB_lay = QtWidgets.QVBoxLayout()
        VB_lay.addStretch()
        VB_lay.addLayout(length_lay)
        VB_lay.addLayout(thick_lay)
        VB_lay.addStretch()

        buttonBox = QtWidgets.QDialogButtonBox()

        buttonBox.setStandardButtons(QtWidgets.QDialogButtonBox.Cancel
        |QtWidgets.QDialogButtonBox.Ok)
        buttonBox.accepted.connect(self.accept) 
        buttonBox.rejected.connect(self.reject)

        grid = QtWidgets.QGridLayout(self)
        grid.addLayout(section_lay, 0, 0, 1, 2)
        grid.addLayout(VB_lay, 1, 0)
        grid.addWidget(self.propertyWidget, 2, 0)
        grid.addWidget(buttonBox, 3, 0, 1, 2)



        self.length_edit.textEdited.connect(self.textchanged)

    def textchanged(self, text):
        print(text)
        self.currenttextedited.emit(text)

class PropertyWidget(QtWidgets.QWidget):
    def __init__(self, parent=None):
       super(PropertyWidget, self).__init__(parent)        
       HB_lay = QtWidgets.QHBoxLayout(self)
       self.Displaylabel = QtWidgets.QLabel('')
       HB_lay.addWidget(self.Displaylabel)
       HB_lay.addStretch()



@QtCore.pyqtSlot(int)
def Display(self, text):
    try:
        L_Display = int(text)
        T_Display = int(text) 
        fmt = "L = {}mm\nT = {}mm"
        self.Displaylabel.setText(fmt.format(L_Display, T_Display))
    except ValueError:
        print("Error")        


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

Answer 1

根据图像中的示例，您希望显示不同的文本，但您将相同的数字转换为整数：L_Display = int(text) 和 T_Display = int(text) 那么您希望如何显示 2 个不同的文本？，显然功能显示需要 2条目（self 的两个不同条目加上我已更改为小写，因为建议函数具有小写名称）。

现在的逻辑如下：如果length_edit 或thick_edit 的任何文本发生变化，那么您必须调用display() 传递新文本。所以解决方案是使用一个槽，连接QLineEdits的textEdited信号，并在其中获取文本并传递文本。

最后我看到你希望QLineEdits 只接收数字，所以一个选择是使用QIntValidator，以便只接受数字（另一个更好的选择是使用QSpinBox 而不是QLineEdit）

import sys
from PyQt5 import QtCore, QtGui, QtWidgets

class WinDialog(QtWidgets.QDialog):
    def __init__(self, parent=None):
        super(WinDialog, self).__init__(parent)

        self.setGeometry(300,300,350,300)
        self.setWindowTitle("Signal & Slot")

        self.propertyWidget = PropertyWidget()

        section_lay = QtWidgets.QHBoxLayout()
        section_label = QtWidgets.QLabel("Name: ")
        section_edit = QtWidgets.QLineEdit('')

        length_lay = QtWidgets.QHBoxLayout()

        length_label = QtWidgets.QLabel("Input a number:     L = ")
        self.length_edit = QtWidgets.QLineEdit()
        self.length_edit.setFocus(True)
        val_lenght = QtGui.QIntValidator(0, 100000, self.length_edit)
        self.length_edit.setValidator(val_lenght)

        thick_lay = QtWidgets.QHBoxLayout()
        thick_label = QtWidgets.QLabel("Input a text: T = ")
        self.thick_edit = QtWidgets.QLineEdit()
        val_thick = QtGui.QIntValidator(0, 100000, self.thick_edit)
        self.thick_edit.setValidator(val_thick)

        section_lay.addWidget(section_label)
        section_lay.addWidget(section_edit)

        length_lay.addWidget(length_label)
        length_lay.addWidget(self.length_edit)
        length_lay.addStretch()

        thick_lay.addWidget(thick_label)
        thick_lay.addWidget(self.thick_edit)
        thick_lay.addStretch()

        VB_lay = QtWidgets.QVBoxLayout()
        VB_lay.addStretch()
        VB_lay.addLayout(length_lay)
        VB_lay.addLayout(thick_lay)
        VB_lay.addStretch()

        buttonBox = QtWidgets.QDialogButtonBox()

        buttonBox.setStandardButtons(QtWidgets.QDialogButtonBox.Cancel
            | QtWidgets.QDialogButtonBox.Ok)
        buttonBox.accepted.connect(self.accept) 
        buttonBox.rejected.connect(self.reject)

        grid = QtWidgets.QGridLayout(self)
        grid.addLayout(section_lay, 0, 0, 1, 2)
        grid.addLayout(VB_lay, 1, 0)
        grid.addWidget(self.propertyWidget, 2, 0)
        grid.addWidget(buttonBox, 3, 0, 1, 2)

        self.length_edit.textEdited.connect(self.onTextEdited)
        self.thick_edit.textEdited.connect(self.onTextEdited)

    def onTextEdited(self):        
        l = self.length_edit.text()
        t = self.thick_edit.text()
        self.propertyWidget.display(l, t)

class PropertyWidget(QtWidgets.QWidget):
    def __init__(self, parent=None):
       super(PropertyWidget, self).__init__(parent)        
       HB_lay = QtWidgets.QHBoxLayout(self)
       self.Displaylabel = QtWidgets.QLabel('')
       HB_lay.addWidget(self.Displaylabel)
       HB_lay.addStretch()

    def display(self, l, t):
        try:
            L_Display = int(l)
            T_Display = int(t) 
            fmt = "L = {}mm\nT = {}mm"
            self.Displaylabel.setText(fmt.format(L_Display, T_Display))
        except ValueError:
            self.Displaylabel.clear()       


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