Python ReportLab 目录页码问题

Question

我需要使用reportlab（v3.6.10）（SimpleDocTemplate）在python（v3.10）中生成带目录的PDF。 页码需要动态设置，但我找到的示例不允许这样做。这是我到目前为止所拥有的。

（目录需要超链接在文档中跳转 - 这在此处有效并共享，因为我没有找到在线示例）

from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.platypus import SimpleDocTemplate, Paragraph, Flowable, Paragraph, PageBreak, Spacer, Table
from reportlab.platypus import PageBreak
from reportlab.platypus.tableofcontents import TableOfContents
from reportlab.lib.units import inch

class DelayedRef(Flowable):
    _ZEROSIZE = True

    def __init__(self, toc, *args):
        self.args = args
        self.toc = toc

    def wrap(self,w,h):
        return 0,0

    def draw(self,*args,**kwd):
        self.toc.addEntry(*self.args)

def addPageNumber(canvas, doc):
    """
    Add the page number
    """
    page_num = canvas.getPageNumber()
    text = "- %s -" % page_num
    canvas.drawRightString(4.5*inch,0.5*inch, text)

def simple_toc():
    docFile = 'test.pdf'
    print(docFile)

    ipsum = '''Lorem ipsum dolor sit amet, consectetur adipiscing elit, 
    sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
    Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris
    nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in
    reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla
    pariatur. Excepteur sint occaecat cupidatat non proident, sunt in
    culpa qui officia deserunt mollit anim id est laborum.'''

    doc = SimpleDocTemplate(docFile)
    story = []
    styles = getSampleStyleSheet()

    story.append(Paragraph("The Title", style=styles['Heading1']))
    story.append(Paragraph("Notes:", style=styles['Normal']))
    story.append(Paragraph(ipsum, style=styles['Normal']))

    story.append(PageBreak())
    story.append(Paragraph('<a name="TOC"/>Table of Contents', style=styles['Heading1']))
    toc = TableOfContents()
    toc.levelStyles = [ParagraphStyle(fontName='Helvetica', fontSize=14, name='Heading1',leftIndent=20, firstLineIndent=-20, spaceBefore=5,leading=16),
                      ParagraphStyle(fontName='Times-Roman', fontSize=14, name='Heading2',leftIndent=20, firstLineIndent=-20, spaceBefore=5,leading=16)]
    story.append(toc)

    story.append(PageBreak())
    story.append(Paragraph('<a name="Part1"/>1. Part 1 Header <a href="#TOC" color="blue">&#8593;</a>', style=styles['Heading1']))
    story.append(DelayedRef(toc, 0, '<a href="#Part1" color="blue">1. Part 1 Header</a>', 1))
    for x in range(10):
        story.append(Paragraph(ipsum, style=styles['Normal']))

    story.append(PageBreak())
    story.append(Paragraph('<a name="Part2"/>2. Part 2 Header <a href="#TOC" color="blue">&#8593;</a>', style=styles['Heading1']))
    story.append(DelayedRef(toc, 0, '<a href="#Part2" color="blue">2. Part 2 Header</a>', 1))
    story.append(Paragraph(ipsum, style=styles['Normal']))


    story.append(Paragraph('<a name="Part21"/>2.1 Part 2.1 Header <a href="#TOC" color="blue">&#8593;</a>', style=styles['Heading2']))
    story.append(DelayedRef(toc, 1, '<a href="#Part21" color="blue">2.1 Part 2.1 Header</a>', 1))
    for x in range(10):
        story.append(Paragraph(ipsum, style=styles['Normal']))

    story.append(PageBreak())
    story.append(Paragraph('<a name="Part3"/>3. Part 3 Header <a href="#TOC" color="blue">&#8593;</a>', style=styles['Heading1']))
    story.append(DelayedRef(toc, 0, '<a href="#Part3" color="blue">3. Part 3 Header</a>',1))

    doc.multiBuild(story, onFirstPage=addPageNumber, onLaterPages=addPageNumber)

if __name__ == '__main__':
    simple_toc()

Answer 1

👍 比 reportlab 的原始解决方案更好（通知） 刚刚添加了很好的页数 用法 ： Story.append(DelayedRef(chapter_toc, level,title))

 class DelayedRef(Flowable):
        _ZEROSIZE = True
    
        def __init__(self, toc,level, title):
            self._toc = toc
            self._level=level
            self._title = title
        def wrap(self,w,h):
            return 0,0
    
        def draw(self,*args,**kwd):
            page_num = self.canv.getPageNumber()
            self._toc.addEntry(self._level,self._title,page_num)