iText GetTextFromPage returns 每页从头开始的文本

Question

我有这个简单的作品。这个问题很奇怪 - 在每次迭代中，reader returns 自 pdf 文档开始以来的整个文本。大概就是这么简单，但是我看不出来。

...
PdfReader reader = new PdfReader ( path );
PdfReaderContentParser parser = new PdfReaderContentParser ( reader );
...
public void Read(int start, int end)
{
    ITextExtractionStrategy strategy = new SimpleTextExtractionStrategy();

    StringBuilder sb = new StringBuilder();

    for (int page = start; page < end; page++)
    {
        try
        {
            sb.Append(PdfTextExtractor.GetTextFromPage(reader, page, strategy));
        }
        catch (Exception ex)
        {
            throw new PdfException(ex.Message, ex.InnerException);
        }

        var p = new Page { Number = page, Content = sb.ToString()};
        sb.Clear();
        PageParsed?.Invoke(this, new PdfEventArgs<Page>(p));
    }
    FileParsed?.Invoke(this, new PdfEventArgs<string>(string.IsNullOrEmpty(Name) ? "File parsed" : Name));
}

Answer 1

strategy 对象保持状态，因此您必须像这样在循环内移动对象实例化：

StringBuilder sb = new StringBuilder();

for (int page = start; page < end; page++)
{
    ITextExtractionStrategy strategy = new SimpleTextExtractionStrategy();
    try
    {
        sb.Append(PdfTextExtractor.GetTextFromPage(reader, page, strategy));
    }
    catch (Exception ex)
    {
        throw new PdfException(ex.Message, ex.InnerException);
    }

    var p = new Page { Number = page, Content = sb.ToString()};
    sb.Clear();
    PageParsed?.Invoke(this, new PdfEventArgs<Page>(p));
}

这将解决您的问题。

iText GetTextFromPage returns 每页从头开始的文本

iText GetTextFromPage returns the text from the begining for evey page

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