python--pyQt5中QLineEdit -- (单行文本框) 文本行编辑

一、获取、提示、设置文本

displayText 获取除NoEcho以外的文本
text 获取所有文本，包括NoEcho
setPlaceholderText 设置占位文本，无法被text或者displayText获取
setText 设置文本

# -*- coding: utf-8 -*-
from PySide6.QtWidgets import QApplication, QWidget, QLineEdit, QPushButton
class Edit(QWidget):
    def __init__(self):
        super(Edit, self).__init__()
        self.UI()
        self.setGeometry(200, 200, 500, 300)
        self.setWindowTitle("QLineEdit")
        self.show()
    def UI(self):
        self.line = QLineEdit("请输入内容", self)
        self.btn = QPushButton("获取文本", self)
        self.btn.setGeometry(50, 120, 200, 30)
        # ///
        self.label_1 = QLineEdit(self)
        self.label_1.setGeometry(50, 50, 200, 30)
        self.label_1.setPlaceholderText("账号")
        self.btn.clicked.connect(self.txt)
    def txt(self):
        print("line text", self.line.text())
        print("displayText ", self.label_1.displayText())
        print("label_2 text", self.label_1.text())
if __name__ == '__main__':
    app = QApplication([])
    edit = Edit()
    app.exec()

二、显示模式

QLineEdit.EchoMode.Normal 正常显示用户输入的文本
QLineEdit.EchoMode.NoEcho 不会显示任何输入的文本
QLineEdit.EchoMode.Password 用户输入时显示一个密码字符
QLineEdit.EchoMode.PasswordEchoOnEdit 开始输入时显示密码字符

from PySide6.QtWidgets import QApplication, QWidget, QLineEdit
class Edit(QWidget):
    def __init__(self):
        super(Edit, self).__init__()
        self.UI()
        self.setGeometry(200, 200, 500, 300)
        self.setWindowTitle("QLineEdit")
        self.show()
    def UI(self):
        self.label_1 = QLineEdit(self)
        self.label_2 = QLineEdit(self)
        self.label_3 = QLineEdit(self)
        self.label_4 = QLineEdit(self)
        self.label_1.setGeometry(50, 50, 200, 30)
        self.label_1.setPlaceholderText("账号")
        # 按字符输入时的形式显示。默认值。
        self.label_1.setEchoMode(QLineEdit.EchoMode.Normal)
        self.label_2.setGeometry(50, 90, 200, 30)
        self.label_2.setPlaceholderText("密码")
        # 不显示任何内容。常见场景：密码的长度也需要被保护
        self.label_2.setEchoMode(QLineEdit.EchoMode.NoEcho)
        self.label_3.setGeometry(50, 130, 200, 30)
        self.label_3.setPlaceholderText("确认密码")
        # 显示时用平台决定的密码掩码字符替代真实输入的字符
        self.label_3.setEchoMode(QLineEdit.EchoMode.Password)
        self.label_4.setGeometry(50, 170, 200, 30)
        self.label_4.setPlaceholderText("邮箱")
        # 当字符正在被编辑时显示
        self.label_4.setEchoMode(QLineEdit.EchoMode.PasswordEchoOnEdit)
if __name__ == '__main__':
    app = QApplication([])
    edit = Edit()
    app.exec()

三、限制操作

setMaxLength(length: int) 设置文本最大长度，默认值为32767
setReadOnly(yes: bool) 设置是否开启只读模式，默认为False

from PySide6.QtWidgets import QApplication, QWidget, QLineEdit, QPushButton
class Edit(QWidget):
    def __init__(self):
        super(Edit, self).__init__()
        self.UI()
        self.setGeometry(200, 200, 500, 300)
        self.setWindowTitle("QLineEdit")
        self.show()
    def UI(self):
        self.label_1 = QLineEdit(self)
        self.label_1.setGeometry(50, 50, 200, 30)
        self.label_1.setMaxLength(11)     # 设置最大长度为11、
        self.label_1.setReadOnly(True)
if __name__ == '__main__':
    app = QApplication([])
    edit = Edit()
    app.exec()

四、文本框其他好玩的操作

.setClearButtonEnabled(enable: bool) 在编辑器内添加清空按钮
.isClearButtonEnabled() -> bool 是否启用了清空按钮
.setDragEnabled(b: bool) 设置是否允许拖拽，默认不允许

from PySide6.QtWidgets import QApplication, QWidget, QLineEdit, QPushButton
class Edit(QWidget):
    def __init__(self):
        super(Edit, self).__init__()
        self.UI()
        self.setGeometry(200, 200, 500, 300)
        self.setWindowTitle("QLineEdit")
        self.show()
    def UI(self):
        self.label_1 = QLineEdit(self)
        self.label_1.setGeometry(50, 50, 200, 30)
        self.label_1.setPlaceholderText("账号")  # 占位文本
        self.label_1.setClearButtonEnabled(True)     # 在编辑器内添加清空按钮
        self.label_1.isClearButtonEnabled()     # 是否启用了清空按钮
        self.label_1.setDragEnabled(True)       # 设置是否允许拖拽
if __name__ == '__main__':
    app = QApplication([])
    edit = Edit()
    app.exec()

LineEdit的读取与写入（后台计算）

filename = QFileDialog.getOpenFileName(self, "选取文件", " ", "Text files (*.txt)")
        print(filename[0])
        # print(type(filename[0]))  # str
        self.report_UI.lineEdit_4.setText(filename[0])  # 将计算的结果生成在LineEdi 里

提示：注意的是必须将计算的结果转换为字符型，否则程序运行不起来