在 PyQt 中使用行号创建文本区域（textEdit）

Question

我想像 Notepad++ 一样在 PyQt 的左侧创建带有行号的 textEdit。我尝试添加另一个 textEdit 但滚动卡住了。我搜索并找到了这个问题，但没有很好的解决方案。

Answer 1

这是您在基于 c++ http://doc.qt.io/qt-5/qtwidgets-widgets-codeeditor-example.html 的pyqt中寻找CodeEditor 示例吗？

将它放在一起用于 python3（我使用 PyQt4 而不是 5，但我想它是相似的）（并且使用 QPlainTextEdit 而不是 QTextEdit，请参阅QTextEdit 与 QPlainTextEdit）：

import sys
from PyQt4.QtGui import *
from PyQt4.QtCore import *

import numpy as np

class LineNumberArea(QWidget):


    def __init__(self, editor):
        super().__init__(editor)
        self.myeditor = editor


    def sizeHint(self):
        return Qsize(self.editor.lineNumberAreaWidth(), 0)


    def paintEvent(self, event):
        self.myeditor.lineNumberAreaPaintEvent(event)


class CodeEditor(QPlainTextEdit):
    def __init__(self):
        super().__init__()
        self.lineNumberArea = LineNumberArea(self)

        self.connect(self, SIGNAL('blockCountChanged(int)'), self.updateLineNumberAreaWidth)
        self.connect(self, SIGNAL('updateRequest(QRect,int)'), self.updateLineNumberArea)
        self.connect(self, SIGNAL('cursorPositionChanged()'), self.highlightCurrentLine)

        self.updateLineNumberAreaWidth(0)


    def lineNumberAreaWidth(self):
        digits = 1
        count = max(1, self.blockCount())
        while count >= 10:
            count /= 10
            digits += 1
        space = 3 + self.fontMetrics().width('9') * digits
        return space


    def updateLineNumberAreaWidth(self, _):
        self.setViewportMargins(self.lineNumberAreaWidth(), 0, 0, 0)


    def updateLineNumberArea(self, rect, dy):

        if dy:
            self.lineNumberArea.scroll(0, dy)
        else:
            self.lineNumberArea.update(0, rect.y(), self.lineNumberArea.width(),
                       rect.height())

        if rect.contains(self.viewport().rect()):
            self.updateLineNumberAreaWidth(0)


    def resizeEvent(self, event):
        super().resizeEvent(event)

        cr = self.contentsRect();
        self.lineNumberArea.setGeometry(QRect(cr.left(), cr.top(),
                    self.lineNumberAreaWidth(), cr.height()))


    def lineNumberAreaPaintEvent(self, event):
        mypainter = QPainter(self.lineNumberArea)

        mypainter.fillRect(event.rect(), Qt.lightGray)

        block = self.firstVisibleBlock()
        blockNumber = block.blockNumber()
        top = self.blockBoundingGeometry(block).translated(self.contentOffset()).top()
        bottom = top + self.blockBoundingRect(block).height()

        # Just to make sure I use the right font
        height = self.fontMetrics().height()
        while block.isValid() and (top <= event.rect().bottom()):
            if block.isVisible() and (bottom >= event.rect().top()):
                number = str(blockNumber + 1)
                mypainter.setPen(Qt.black)
                mypainter.drawText(0, top, self.lineNumberArea.width(), height,
                 Qt.AlignRight, number)

            block = block.next()
            top = bottom
            bottom = top + self.blockBoundingRect(block).height()
            blockNumber += 1


    def highlightCurrentLine(self):
        extraSelections = []

        if not self.isReadOnly():
            selection = QTextEdit.ExtraSelection()

            lineColor = QColor(Qt.yellow).lighter(160)

            selection.format.setBackground(lineColor)
            selection.format.setProperty(QTextFormat.FullWidthSelection, True)
            selection.cursor = self.textCursor()
            selection.cursor.clearSelection()
            extraSelections.append(selection)
        self.setExtraSelections(extraSelections)


if __name__ == "__main__":
    app = QApplication(sys.argv)

    txt = CodeEditor()
    txt.show()

    sys.exit(app.exec_())

Answer 2

这是我的 PyQt5 和 python3 代码，结合了 @Dan-Dev 和 @Axel Schneider。您可以直接运行它，或者简单地导入 use code from QCodeEditor import QCodeEditor。

#!/usr/bin/python3
# QcodeEditor.py by acbetter.
# -*- coding: utf-8 -*-

from PyQt5.QtCore import Qt, QRect, QSize
from PyQt5.QtWidgets import QWidget, QPlainTextEdit, QTextEdit
from PyQt5.QtGui import QColor, QPainter, QTextFormat


class QLineNumberArea(QWidget):
    def __init__(self, editor):
        super().__init__(editor)
        self.codeEditor = editor

    def sizeHint(self):
        return QSize(self.editor.lineNumberAreaWidth(), 0)

    def paintEvent(self, event):
        self.codeEditor.lineNumberAreaPaintEvent(event)


class QCodeEditor(QPlainTextEdit):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.lineNumberArea = QLineNumberArea(self)
        self.blockCountChanged.connect(self.updateLineNumberAreaWidth)
        self.updateRequest.connect(self.updateLineNumberArea)
        self.cursorPositionChanged.connect(self.highlightCurrentLine)
        self.updateLineNumberAreaWidth(0)

    def lineNumberAreaWidth(self):
        digits = 1
        max_value = max(1, self.blockCount())
        while max_value >= 10:
            max_value /= 10
            digits += 1
        space = 3 + self.fontMetrics().width('9') * digits
        return space

    def updateLineNumberAreaWidth(self, _):
        self.setViewportMargins(self.lineNumberAreaWidth(), 0, 0, 0)

    def updateLineNumberArea(self, rect, dy):
        if dy:
            self.lineNumberArea.scroll(0, dy)
        else:
            self.lineNumberArea.update(0, rect.y(), self.lineNumberArea.width(), rect.height())
        if rect.contains(self.viewport().rect()):
            self.updateLineNumberAreaWidth(0)

    def resizeEvent(self, event):
        super().resizeEvent(event)
        cr = self.contentsRect()
        self.lineNumberArea.setGeometry(QRect(cr.left(), cr.top(), self.lineNumberAreaWidth(), cr.height()))

    def highlightCurrentLine(self):
        extraSelections = []
        if not self.isReadOnly():
            selection = QTextEdit.ExtraSelection()
            lineColor = QColor(Qt.yellow).lighter(160)
            selection.format.setBackground(lineColor)
            selection.format.setProperty(QTextFormat.FullWidthSelection, True)
            selection.cursor = self.textCursor()
            selection.cursor.clearSelection()
            extraSelections.append(selection)
        self.setExtraSelections(extraSelections)

    def lineNumberAreaPaintEvent(self, event):
        painter = QPainter(self.lineNumberArea)

        painter.fillRect(event.rect(), Qt.lightGray)

        block = self.firstVisibleBlock()
        blockNumber = block.blockNumber()
        top = self.blockBoundingGeometry(block).translated(self.contentOffset()).top()
        bottom = top + self.blockBoundingRect(block).height()

        # Just to make sure I use the right font
        height = self.fontMetrics().height()
        while block.isValid() and (top <= event.rect().bottom()):
            if block.isVisible() and (bottom >= event.rect().top()):
                number = str(blockNumber + 1)
                painter.setPen(Qt.black)
                painter.drawText(0, top, self.lineNumberArea.width(), height, Qt.AlignRight, number)

            block = block.next()
            top = bottom
            bottom = top + self.blockBoundingRect(block).height()
            blockNumber += 1


if __name__ == '__main__':
    import sys
    from PyQt5.QtWidgets import QApplication

    app = QApplication(sys.argv)
    codeEditor = QCodeEditor()
    codeEditor.show()
    sys.exit(app.exec_())

它是这样运行的。

顺便说一句，如果你想在 Qt Designer 中使用它，你应该这样做，并将 *.ui 文件放在 QCodeEditor.py 文件路径的同一目录中，除非你设置环境变量。并且，您需要通过命令将 *.ui 文件转换为 *.py 文件pyuic5 -x *.ui -o *.py。希望有帮助~