QTextEdit
是 PyQt 中用于编辑和显示多行文本的组件。它允许用户输入、编辑和格式化文本,并支持丰富的文本编辑功能。以下是关于 QTextEdit
的一些详细解释和示例:
QTextEdit
对象:要创建一个 QTextEdit
对象,只需实例化它,然后将其添加到布局或窗口中。例如:
from PyQt5.QtWidgets import QApplication, QWidget, QTextEdit, QVBoxLayout
app = QApplication([])
window = QWidget()
layout = QVBoxLayout()
text_edit = QTextEdit()
layout.addWidget(text_edit)
window.setLayout(layout)
window.show()
app.exec_()
可以使用 setPlainText
方法设置文本内容,使用 toPlainText
方法获取文本内容。例如:
text_edit.setPlainText("Hello, PyQt5!")
text = text_edit.toPlainText()
使用 setReadOnly
方法来设置文本编辑框是否为只读状态。例如:
text_edit.setReadOnly(True) # Make it read-only
text_edit.setReadOnly(False) # Make it editable
使用 setFont
方法可以为文本内容设置字体,也可以使用 setFontPointSize
来设置字体大小。要更改选定文本的字体和格式,可以使用 QTextCursor
和 QTextCharFormat
,如前面的示例所示。
QTextEdit
支持丰富的文本格式化功能,例如粗体、斜体、下划线、颜色、对齐等。可以通过在文本编辑框中选择文本,然后使用工具栏或编程方式应用这些格式。
from PyQt5.QtGui import QTextCursor
cursor = text_edit.textCursor()
char_format = QTextCharFormat()
char_format.setFontWeight(QFont.Bold)
cursor.mergeCharFormat(char_format)
使用 verticalScrollBar
和 horizontalScrollBar
方法可以获取滚动条,从而实现对 QTextEdit
的滚动控制。
QTextEdit
支持多种信号和槽,用于处理文本变化、光标移动、文本选择等事件。
text_edit.textChanged.connect(my_text_changed_handler)
text_edit.cursorPositionChanged.connect(my_cursor_moved_handler)
以上仅是 QTextEdit
的一些常见用法和功能。你可以通过查阅 PyQt5 的文档来深入了解其更多特性和方法。
import sys
from PyQt5.QtWidgets import QApplication, QWidget, QTextEdit, QVBoxLayout
from PyQt5.QtGui import QTextCursor, QTextBlockFormat
from PyQt5.QtCore import Qt
class CenteredAllLinesTextDisplay(QWidget):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
self.setWindowTitle('Centered All Lines Text Display Example')
self.setGeometry(100, 100, 400, 300)
text = "Hello, PyQt5!\nThis is a centered text display example with all lines centered."
text_edit = QTextEdit(self)
text_edit.setPlainText(text)
text_edit.setReadOnly(True) # Make the text edit widget read-only
# Center align all lines
cursor = QTextCursor(text_edit.document())
cursor.movePosition(QTextCursor.Start)
while not cursor.atEnd():
cursor.movePosition(QTextCursor.StartOfBlock)
cursor.select(QTextCursor.BlockUnderCursor)
block_format = QTextBlockFormat()
block_format.setAlignment(Qt.AlignCenter)
cursor.mergeBlockFormat(block_format)
cursor.movePosition(QTextCursor.EndOfBlock)
cursor.movePosition(QTextCursor.NextBlock)
layout = QVBoxLayout()
layout.addWidget(text_edit)
self.setLayout(layout)
if __name__ == '__main__':
app = QApplication(sys.argv)
window = CenteredAllLinesTextDisplay()
window.show()
sys.exit(app.exec_())
import sys
from PyQt5.QtWidgets import QApplication, QWidget, QTextEdit, QVBoxLayout, QPushButton, QFontDialog
from PyQt5.QtGui import QTextCursor, QTextCharFormat, QFont
class FontSizeTextDisplay(QWidget):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
self.setWindowTitle('Font Size Text Display Example')
self.setGeometry(100, 100, 400, 300)
self.text_edit = QTextEdit(self)
self.text_edit.setPlainText("Hello, PyQt5!\nThis is a font size text display example.")
self.text_edit.setReadOnly(True) # Make the text edit widget read-only
change_font_size_button = QPushButton('Change Font Size', self)
change_font_size_button.clicked.connect(self.changeFontSize)
layout = QVBoxLayout()
layout.addWidget(self.text_edit)
layout.addWidget(change_font_size_button)
self.setLayout(layout)
def changeFontSize(self):
font, ok = QFontDialog.getFont(self)
if ok:
cursor = self.text_edit.textCursor()
char_format = QTextCharFormat()
char_format.setFontPointSize(font.pointSize())
cursor.mergeCharFormat(char_format)
self.text_edit.setCurrentFont(font)
if __name__ == '__main__':
app = QApplication(sys.argv)
window = FontSizeTextDisplay()
window.show()
sys.exit(app.exec_())
import sys
from PyQt5.QtWidgets import QApplication, QWidget, QTextEdit, QVBoxLayout
from PyQt5.QtGui import QFont
class DefaultFontSizeTextDisplay(QWidget):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
self.setWindowTitle('Default Font Size Text Display Example')
self.setGeometry(100, 100, 400, 300)
self.text_edit = QTextEdit(self)
self.text_edit.setPlainText("Hello, PyQt5!\nThis is a default font size text display example.")
default_font = QFont("Arial", 14) # Set the default font and size
self.text_edit.setFont(default_font)
layout = QVBoxLayout()
layout.addWidget(self.text_edit)
self.setLayout(layout)
if __name__ == '__main__':
app = QApplication(sys.argv)
window = DefaultFontSizeTextDisplay()
window.show()
sys.exit(app.exec_())